SPACE GASS 12 Manual

SPACE GASS 12 User Manual

Table of Contents Introduction

1

Introduction How to use this manual Legal notice Hardware requirements Product support Hardware locks and insurance New features

1 2 6 10 11 12 13

Installation and Configuration

27

Installation and configuration Installing SPACE GASS Configuring SPACE GASS Folders and files Text formatting General configuration Graphics scale calibration Graphics colors General colors Problem size limits Renderer configuration Customizing toolbars Customizing property panels The SPACE GASS utility tool

27 28 29 30 33 35 39 40 42 43 44 48 52 55

Getting Started

59

Getting started Starting SPACE GASS Command line options The main SPACE GASS window The status line Using the mouse Dialogue boxes

59 60 61 64 66 69 70

iii

SPACE GASS 12 User Manual Data entry Managing job files Starting a new job Opening a job Merging jobs Saving a job Deleting a job Cleaning up a job Running a macro Running a script Job status Shortcuts

72 75 76 77 78 80 81 82 84 86 90 91

Input Methods

95

Input methods

95

Linking to Other Programs

97

Linking to other programs CIMSteel/2 Step, IFC Step and Revit links Import links Export links Special Revit Structure links DXF links Importing DXF files Exporting DXF files

97 100 104 108 111 114 115 116

Modelling the Structure

121

Modelling the structure Coordinate systems Sign conventions Ill-conditioning and instabilities

121 122 128 134

Project Data

137

Project data

137

iv

Table of Contents Units Job details and attachments Node data Member data Plate data Node restraint data Section property data Standard section libraries Shape builder Flipping a section Column and beam Tee sections Angle sections Material property data Master-slave constraint data Member offset data Node load data Prescribed node displacement data Member concentrated load data Member distributed force data Member distributed torsion data Thermal load data Member prestress data Plate pressure data Self weight data Combination load case data Load case title data Lumped mass data Spectral load data Spectral curve editor Importing a spectral curve Area load data Sea load data Moving load data

138 140 142 144 151 158 162 166 167 175 176 177 179 181 189 191 192 194 196 199 201 203 205 207 209 212 213 216 219 221 223 226 227

Text File Input

229

Text file input Text file format Initiator Headings text Nodes text

229 230 231 232 233

v

SPACE GASS 12 User Manual Members text Plates text Node restraints text Section properties text Material properties text Master-slave constraints text Member offset text Node loads text Prescribed node displacements text Member concentrated loads text Member distributed forces text Member distributed torsions text Thermal loads text Member prestress loads text Plate pressure loads text Self weight text Combination load cases text Load case titles text Lumped masses text Spectral loads text Steel member design text Terminator Text file errors Text file example

234 236 237 238 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 259 260 265

Structure Wizard

269

Structure wizard

269

Portal Frame Builder

273

Portal frame builder Portal frame geometry Portal frame extra data Portal frame sections and materials Portal frame loads Portal frame load cases Portal frame design Portal frame assumptions

273 275 279 282 283 288 289 291

vi

Table of Contents Datasheet Input

293

Datasheet input Using datasheets

293 294

Graphical Input

301

Graphical overview The renderer The traditional graphics window Selection methods Select all Attachment and alignment methods Grid Snap Ortho Attach Plane Coordinates Using the keyboard to position points Infotips Property panels Multiple viewports Node properties Member properties Plate properties Node restraints Section properties Material properties Master-slave constraints Member offsets Copy node properties Copy member properties Copy plate properties Draw Move Rotate Copy Mirror Delete

301 303 329 338 340 341 345 348 350 351 354 356 358 360 361 366 368 371 375 378 379 380 381 382 383 384 385 386 390 392 393 396 397

vii

SPACE GASS 12 User Manual Stretch Scale Generate arc Generate bends Subdivide Mesh Connect Intersect Extend Remove intermediate nodes Remove crossed member nodes Move intermediate nodes Align members Generate taper/haunch Reverse member direction Reverse plate direction Align plate axes Renumber Connectivity check Node loads Prescribed node displacements Member concentrated loads Member distributed forces Member distributed torsions Thermal loads Member prestress loads Plate pressure loads Self weight Combination load cases Load case titles Lumped masses Static load to mass conversion Spectral loads Area loads Sea Loads Moving loads Varying plate pressure loads Copy node loads Copy member loads Copy plate loads Managing load cases View nodes / members / plates

viii

398 399 400 401 403 405 408 409 411 412 413 414 415 417 420 421 423 424 427 428 430 432 434 437 440 443 445 447 448 452 453 455 457 458 463 472 485 490 491 492 493 495

Table of Contents View node / member / plate properties View global origin View local axes View member origins View labelling and annotation Load case titles viewer View results in local XY or XZ plane View diagrams View plate contours View envelope View dynamic mode shapes View buckling mode shapes View steel member design groups View steel member top flanges View steel member flange restraints View steel member design results Query frame Query analysis results Query steel member design results Redraw Zoom Pan Scales Find Filters Views Viewpoint View manager Notes Measurements and dimensions Gridlines Textures Transparency Repeat last command

496 497 498 499 500 502 504 505 506 509 510 512 513 514 515 516 518 519 521 522 523 525 526 528 532 535 537 540 541 544 547 549 551 554

Analysis

555

Analysis Static analysis Displacements, actions and reactions P-D effect

555 556 558 560

ix

SPACE GASS 12 User Manual P-d effect Tension-only and compression-only effects Cable members Non-linear analysis procedure Static analysis buckling The wavefront optimizer The wavefront analysis method A quick frontwidth calculation method The wavefront method in more detail Running a static analysis Static analysis results Dynamic frequency analysis Modelling considerations Running a dynamic frequency analysis Dynamic frequency analysis results Dynamic response analysis Running a dynamic response analysis Dynamic response procedure Dynamic response analysis results Buckling analysis Buckling effective lengths Special buckling considerations Running a buckling analysis Buckling analysis results Analysis warnings and errors

561 562 564 567 569 570 576 577 578 579 588 589 590 591 598 599 601 605 606 609 611 613 616 622 624

Steel Member Design

629

Steel member design Steel member input methods Auto-create steel members Steel member input form Steel member input datasheet Copy steel member properties Steel member design data Steel member design sign conventions Member groups Flange restraints Column and beam Tees Running a steel member design Updating analysis member sizes

629 631 632 637 640 641 642 653 654 660 668 669 678

x

Table of Contents Serviceability check The steel member design/check process Design groups and intermediate stations Design segments Section check Member check Critical flange Effective flange restraints Twist factor Load height factor Lateral rotation factor End moment ratios and other factors Eccentric effects for compression members Eccentric effects for tension members The code check Steel member design results Steel member design/check assumptions BS5950-1:2000 code specific items Hong Kong CP2011 code specific items AISC 360-10 code specific items Eurocode EN 1993-1-1:2005 code specific items AS/NZS 4600:2005 code specific items Steel member design/check errors

680 681 682 683 684 685 686 687 689 690 692 694 695 696 697 698 700 706 712 715 721 726 731

Steel Connection Design

735

Steel connection design Creating and editing connections The connection manager Design considerations Connection reports Connection preferences

735 737 752 759 761 763

Concrete Column Design

765

Concrete column design Running a concrete column design Concrete column configuration Concrete column design results Concrete column assumptions and notes

765 766 774 776 777

xi

SPACE GASS 12 User Manual Output

779

Output Page setup View text report Print preview Print text report Print graphics The status report

779 784 787 788 791 792 793

Standard Libraries

795

Standard libraries The library editor

795 797

Importing and exporting

800

Importing old libraries Section libraries Material libraries Bolt libraries Plate libraries Weld libraries Reinforcing bar libraries Spectral curve libraries Vehicle libraries

801 802 804 805 806 807 808 809 810

Portal Frame Analysis

811

Portal frame analysis Geometry and loads Method of input Analysis procedure Analysis results Graphical output Analysis input report Static analysis report (itemised) Static analysis report (enveloped) Bill of materials report

811 813 818 820 821 822 827 843 867 882

xii

Table of Contents Dynamic frequency analysis report Dynamic response analysis report Buckling analysis report

883 884 886

Portal Frame Member Design

889

Portal frame member design Member design results Steel member design report

889 894 896

Portal Frame Connection Design

897

Portal frame connection design Connection design results

897 899

Cable Analysis

921

Cable analysis Method of input Analysis procedure Analysis results

921 923 924 925

Converting Old Jobs

935

Converting old jobs

935

Bibliography

937

Bibliography

937

Index

941

xiii

Introduction Introduction SPACE GASS 12 60th Edition, July 2014 SPACE GASS is a general purpose structural analysis and design program for 2D and 3D frames, trusses, grillages, beams and plates. It includes a full complement of features that make it suitable for any job from small beams, trusses and portal frames to large high rise buildings, towers and bridges. To see the new features recently added, refer to New features. Its emphasis on graphics means that you easily see the status of your model at all times. In fact, the extensive range of graphical editing tools allow you to input your model or make changes entirely within the graphical editor. Of course, if you prefer to work with datasheets or other methods of input then they are available too. A structure wizard automatically generates the initial data for many typical structures which you can then manipulate to create the exact model you want. State of the art solvers for linear and non-linear static analysis, dynamic analysis and buckling analysis are available. Steel and concrete design modules for various international codes of practice are also available. Graphical and text reports can be generated for any parts of the structural model. Comprehensive filters that can be defined graphically allow you to customize your graphical views and output reports to include just want you want to see. Although SPACE GASS is a comprehensive program with many advanced features, its logical menu structure, toolbars and graphical emphasis makes it easy to learn and use, even for first time users. If you have questions or need help then you will probably find the answers in this manual.

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How to use this manual Illustrated as follows is an example of each of the three outline styles used in this manual. These styles are designed to draw your attention to information in one of three ways: as a hint, an important note or general note. Hints are non-essential, but useful, pieces of information which will improve your understanding of the program. Hints sometimes identify a special way of doing something and are typically quite specific. Important notes should be carefully read and understood. They outline information that is vital to the effective use of the software. Notes identify articles of information which are meant as an aside to aid your understanding of SPACE GASS. Some notes are quite general in nature and do not give reference to a specific procedure. Notes may also serve to draw your attention to specific interpretation. HINTS This is an example of the SPACE GASS HINTS style and icon. IMPORTANT NOTES ! IMPORTANT NOTE ! This is an example of the SPACE GASS important note style and icon. NOTES

This is an example of the SPACE GASS NOTES style and icon. Following is a brief overview of each section in the manual. Chapter 1 "Installation and Configuration" Deals with the installation and configuration of SPACE GASS. Once the software is installed and running correctly, you should not have to refer to this chapter again.

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Introduction Chapter 2 "Getting Started" If you are new to frame analysis programs or Windows programs in general, then you should read this chapter before attempting to run a job. It provides very good basic information that you will need to know about the operation of SPACE GASS. Chapter 3 "Input Methods" Explains the four main methods of inputting and editing your model. Chapter 4 "Linking to Other Programs" Describes how data can be transferred between SPACE GASS and other structural analysis, CAD and building management programs. Chapter 5 "Modelling the Structure" Discusses the basics of how you can model a structure with SPACE GASS and includes information on nodes, members, restraints, coordinate systems, sign conventions, etc. Chapter 6 "Project Data" Gives a detailed description of each type of data that can be used in the frame analysis part of the model. Data for steel and concrete design is not included (see later chapters). This chapter deals only with the data itself, and leaves the discussion of the numerous methods that you can use to input the data to later chapters. Chapter 7 "Text File Input" Describes the format of standard SPACE GASS text files. This is one of the five methods of data entry. You can type your data into a standard text file and then import it into SPACE GASS. Standard text files can also be used as an alternative for permanent storage of data. Chapter 8 "Structure Wizard" Another method of input involves selecting from a number of standard structures, answering a few simple questions about the structure selected, and then having the structure wizard generate all of the frame data for you. Any of the other data entry methods can be used to modify the data after it has been generated using this method. Chapter 9 "Portal Frame Builder" Described in detail the portal frame builder and how it can be used to generate the complete model of a portal frame building including the full structure, loads (including wind loads) and design data.

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SPACE GASS 12 User Manual Chapter 10 "Datasheet Input" Is a modified form of spreadsheet input which allows you to input or edit any parts of the frame data or steel design data. Along with graphical input, this is probably one of the most useful and versatile methods of data entry. Chapter 11 "Graphical Input" Covers all of the graphics facilities, including those in the renderer. This includes graphical structure input, graphical load input, graphical steel design input, connection drawing detail, graphical output of loading, displacement, bending moment, shear force, stress, axial force and animated mode shape diagrams. Full descriptions are also given for the many commands associated with drawing, moving, copying, rotating, mirroring, erasing, zooming, panning, scaling, coordinate systems, changing the viewpoint, labelling, querying diagrams, viewing the rendered model, hidden line removal, renumbering, etc. Chapter 12 "Analysis" The static, dynamic and buckling analysis modules, together with their options and control parameters are fully described here. Chapter 13 "Steel Member Design" Details the use of the steel member design module. Please pay particular attention to the assumptions listed near the end. Chapter 14 "Steel Connection Design" Details the use of the steel connection design module. Chapter 15 "Concrete Column Design" Details the use of the reinforced concrete column design module. Please pay particular attention to the assumptions listed near the end. Chapter 16 "Output" Describes the types of output reports and graphics hardcopies that can be obtained and the options that are available for sorting, formatting, enveloping, positioning on the page, etc. Chapter 17 "Standard Libraries" SPACE GASS is supplied with a number of standard section, material, bolt, plate and weld libraries. This chapter provides a complete guide on how you can customise any of these libraries, or create your own section libraries.

4

Introduction Appendix A "Portal Frame Analysis" Presents a detailed report on the analysis of a typical steel portal frame. Full discussions regarding the input data and the decisions involved in producing it are included, together with complete printouts of the analysis input and output reports. Appendix B "Portal Frame Member Design" Presents a detailed report on the member design for the steel portal frame analysed in appendix B. It includes a discussion on how the steel members are being modelled, together with complete printouts of the member design input and output reports. Appendix C "Portal Frame Connection Design" Presents a detailed report on the connection design for the steel portal frame analysed in appendix B. It includes a discussion on how the steel connections are being modelled, together with complete printouts of the connection design input and output reports. Appendix D "Cable Analysis" Presents a worked example demonstrating the input and analysis of a 30m tall, guyed mast. The catenary cable equations are used to calculate the axial force in a nominal guy member, this is then compared to the result obtained from SPACE GASS. Appendix E "Converting Old Jobs" Explains how you can convert data files that were produced with SPACE GASS v1, v2 or v3 for loading into the latest version. Note that data files produced with SPACE GASS 4 or later are automatically converted into the latest format when they are opened. Appendix F "Bibliography" A list of references.

5


Legal notice End User License Agreement Notice to Licensee: This End User License Agreement (the "Agreement") is a legal agreement between you and I.T.S. Integrated Technical Software Pty Ltd (ACN 086 605 567) ("ITS"), a registered company under the Corporations Law of the State of Victoria, Australia. BY USING THIS PRODUCT, YOU AGREE TO BE BOUND BY THE TERMS AND CONDITIONS OF THIS AGREEMENT. If you do not agree to all the terms and conditions of this Agreement or if you do not have the authority to agree to all the terms and conditions of this Agreement on behalf of the licensee then you MUST NOT USE THE PRODUCT. Provided the Product has not been used and is not a loan, student or evaluation version, you may return it to your place of purchase for a full refund. 1. Definitions. For the purposes of this Agreement, the following terms shall have the following meanings: 1.1 "Product" shall mean and include the SPACE GASS software, updates, CDs, computer disks, Security Devices, help files, reference manual or other instructions, technical support or any other software, items or information of any kind provided by ITS or obtained from the www.spacegass.com web site. 1.2 "Software" shall mean all software included in the Product. 1.3 "Security Devices" shall mean and include hardware or software that limits the number of users that may operate the Software simultaneously, or imposes an Expiry Date beyond which the Software cannot be used, or prevents certain parts of the Software from being used. 1.4 "Expiry Date" shall mean the date imposed by any Security Devices beyond which the Software cannot be used. 1.5 "ITS" includes its employees, agents and suppliers. 2. License. The Product is protected by copyright laws and international copyright treaties, as well as other intellectual property laws and treaties. The Product is licensed, not sold.

6

Introduction 2.1 Grant of License. Subject to the terms and conditions of this Agreement, ITS grants to you a non-exclusive license to use the Product during the term of this Agreement. 2.2 User Limit. The Software may be installed on an unlimited number of computers, however the maximum number of users operating it simultaneously may not exceed the user limit imposed by the Security Devices. 2.3 Reference Manual. You may make such copies of the reference manual as are reasonably necessary for your use of the Product by the permitted number of simultaneous users, but you may not make copies of the reference manual for any other purpose without the prior written consent of ITS. 3. Ownership; Proprietary Rights. ITS shall at all times be the owner of and have all rights to the Product, and all intellectual property associated therewith, including but not limited to patents, copyrights, trade names and marks, domain names, and trade secrets related thereto. The Product is protected by copyright laws and international treaty provisions. Nothing herein shall cause or imply a sale, license or transfer of any intellectual property rights of ITS to you or to any third party, except as expressly set forth herein. You may not reverse engineer, decompile, disassemble, or otherwise attempt to discover the source code of the Software. You may not attempt to reverse engineer, duplicate or bypass any Security Devices. 4. Disclaimers. ITS makes no warranties or representations as to the Product to you or to any other party. To the extent permitted by applicable law, all implied warranties, including, but not limited to, the implied warranties of merchantability and fitness for a particular purpose, are hereby disclaimed. 5. Limitation of Liability. To the maximum extent permitted by applicable law, in no event shall ITS be liable for any punitive, exemplary, consequential, indirect, incidental, or special damages arising from or related to the use of the Product by any party, including without limitation damages arising from loss of data, loss of revenue or profits or failure to realize savings or other benefits, even if ITS has been advised of or should be aware of the possibility of such damages. In the event of any defect in the Product ITS may, at its option; i. ii. iii.

replace the Product or supply its equivalent; repair the Product; pay for the cost of replacing the Product or of acquiring its equivalent; or

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SPACE GASS 12 User Manual iv.

pay for the cost of having the error in the Product rectified.

To the extent that the Product involves providing a service, in the event of any error or defect in the provision of that service ITS may, at its option; i. ii.

supply the service again; or pay for the cost of having the service supplied again.

Because some states and jurisdictions do not allow the exclusion or limitation of liability, the above limitation may not apply to you. 6. Indemnification. You, at your sole expense, will defend, indemnify and hold ITS harmless from and with respect to any loss or damage (including reasonable attorneys’ fees and costs) incurred in connection with, any suit or proceeding brought by a third party against ITS insofar as such suit or proceeding shall be based upon (i) any claim arising out of or relating to your use of the Product except where such claim alleges that the Software infringes or constitutes wrongful use of any copyright, trade secret, patent or trade mark of any third party; or (ii) any claim arising out of or relating to any act or omission by you. You will pay any damages and costs assessed against ITS (or paid or payable by ITS pursuant to a settlement agreement) in connection with such a suit or proceeding. 7. Changes to the Product. ITS may change the Product from time to time without notice to you and shall not be under any obligation to provide you with any notification of such change. 8. Non-Transferability. You may not rent, lease, sub-license, lend or transfer the Product to another person or legal entity without the prior written consent of ITS. 9. Term and Termination. The term of this Agreement shall commence on the date that you install or use the Product and shall continue (unless earlier terminated as provided herein) until the Expiry Date, or in perpetuity if no Expiry Date is imposed. Without prejudice to any other rights, ITS may terminate this Agreement at any time if you fail to comply with its terms and conditions. Upon termination of this Agreement for any reason whatsoever, you shall cease all use of the Product and remove all copies of the Software from your computers. 10. General. 10.1 Assignment. You may not assign or transfer this Agreement or any of your rights, duties or obligations hereunder and this Agreement may not be

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Introduction involuntarily assigned or assigned by operation of law, without the prior written consent of ITS, which consent may be granted or withheld by ITS in its sole discretion. 10.2 Severability. Each provision of this Agreement is intended to be severable. If any covenant, condition or other provision contained in this Agreement is held to be invalid or illegal by any court of competent jurisdiction, such provision shall be deemed severable from the remainder of the Agreement and shall in no way affect, impair or invalidate any other covenant, condition or other provision contained in this Agreement. If such covenant, condition or other provision shall be deemed invalid due to its scope or breadth, such covenant, condition or other provision shall be deemed valid to the extent of the scope or breadth permitted by law. 10.3 Governing Law. You agree that the use of the Product by you shall be governed by the laws of the State of Victoria and the Commonwealth of Australia, and you consent to the non-exclusive jurisdiction of the courts of that State and the Commonwealth. 10.4 Attorneys’ Fees. If any legal action is brought arising out of or relating to this Agreement, the prevailing party shall be entitled to receive its reasonable attorneys’ fees and court costs in addition to any other relief it may be entitled. 10.5 Entire Agreement. This Agreement is the complete and exclusive statement of the agreement of the parties hereto with respect to the subject matter hereof, and supercedes all prior and concurrent agreements, promises, proposals, representations and warranties, oral or written, with respect to the subject matter hereof.

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Hardware requirements    

Windows XP/Vista/7/8 (Windows 7 or 8 preferred). 32-bit or 64-bit Windows operating system (64-bit preferred). Intel or AMD CPU (Intel multi-core preferred). Any graphics card with at least 2Gb RAM (NVIDIA preferred). Note that SPACE GASS 12 supports hardware acceleration with NVIDIA and ATI graphics cards and will perform best with those brands. For other graphics cards, operations such as zooming, panning, rotating and scaling in the renderer will run considerably slower. It is expected that future versions of SPACE GASS 12 will support hardware acceleration in all modern graphics cards.

10

Introduction

Product support Product support includes:     

Notification of any program modifications or enhancements as they become available. Update facility for those users wishing to upgrade to the latest version. Replacement of any software which is found to be defective through no fault of the user or which does not conform to the general published function of the software. Telephone, facsimile and email support by I.T.S. or an authorised dealer. Comprehensive Internet web site providing latest information, drivers, updates, libraries, etc. for all registered SPACE GASS users.

I.T.S. reserves the right to charge for telephone, facsimile or email support.

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Hardware locks and insurance SPACE GASS is sometimes supplied with a hardware lock that must be inserted into the parallel or USB port before the software will run. If the hardware lock is faulty or becomes damaged or destroyed, it can be replaced for a nominal fee provided that a remnant of the lock showing a valid serial number can be produced proving that it is a genuine SPACE GASS hardware lock. The hardware lock cannot be replaced for a nominal fee if it is lost or stolen and, for this reason, it is recommended that the user insure the software package and hardware lock for the full current market value of the software.

12

Introduction

New features The key new features added in SPACE GASS since v10 are as follows. Note that minor new features, enhancements and bug fixes are not listed here. Version 12.00 This is a major upgrade containing many new features and substantial performance improvements, especially in the analysis solvers and graphics engine. It also makes the renderer the main interface for the program. Introduced a new "Paradise" solver for the static, buckling and dynamic frequency analysis modules. It is a sparse matrix solver that fully utilizes the parallel processing capabilities of modern multi-core CPUs. The new solver is usually between 10 and 100 times faster than SPACE GASS 11. The most dramatic speed savings occur with jobs that have a large matrix frontwidth and lots of load cases. The renderer graphics now fully utilizes the parallel processors on the graphics card rather than doing the graphics calculations on the main CPU. This means that deflection diagrams, bending moment diagrams, shear force diagrams, etc. can be scaled up and down smoothly regardless of the size of the job, even in fully rendered 3D mode. The renderer has been given a major overhaul with a new user interface that now has almost all of the functionality of the traditional SPACE GASS window. This means that you can do everything in the renderer without constantly having to switch back to the traditional SPACE GASS window. The new functionality in the renderer includes:  New user interface that can be configured with different skins and user defined layouts.  Substantial performance increases and no annoying delays or pauses.  Opening and saving of jobs.  Generating reports.  Structure wizards.  Datasheets.  Node, member and plate drawing and editing tools.  Loading input and editing tools.  Filtering.  Scaling.

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SPACE GASS 12 User Manual     

Static, buckling and dynamic analysis. Steel and concrete design. Display of all analysis result diagrams such as deflections, moments, contours, etc. Ability to show fully rendered deflections rather than just wireframe. Animated mode shapes.

Version 11.09 Released an all new Steel Connection Design module for AS4100 that complies with the latest ASI design guides. Released a new Steel Member Design module for AS4600 that works with the cold formed sections from manufacturer including Lysaght, Stramit, Duragal and others. Supported sections include Cees, Zeds, angles, tophats, channels, back-toback Cees, CHSs, SHSs and RHSs. New cold formed section libraries for Lysaght, Stramit and Duragal have also been included. The Portal frame builder now automatically creates all of the main connections in the building. They can then be used in the steel connection design module. Allow a steel member design to be performed via a script file with the user being able to control the design groups, sections properties and load cases considered. Allow exporting of steel member design/check summaries to a text file or MSExcel/Access/Word file. Version 11.08 Various new script commands have been added that allow you to have more control over importing/exporting and analysis. You can also pause the script to see what stage it is up to at any point. Version 11.05 Released a Portal Frame Builder module for the modelling of portal frame buildings in SPACE GASS. It generates the full structural model plus dead loads, live loads, wind loads and steel member design data. The module supports gable (symmetrical and asymmetrical) and monoslope roofs, overhangs, knee braces, haunches, fly bracing, uneven frame spacings, openings, roof/wall bracing and end wall props. Wind loads are generated in accordance with AS/NZS 1170.2:2011 for all regions in Australia and New Zealand.

14

Introduction

Version 11.01 Released a Sea Load module for the calculation of wave, current, marine growth and buoyancy loads on submerged structures in marine and offshore environments. Version 11.00 This is a major new version that includes a new 3D renderer with full editing capabilities. Of course you can still edit your model in the traditional SPACE GASS window, however the editing tools in the renderer are generally more advanced and offer additional features over the traditional editing tools. Some of the load input tools, design data tools and analysis results diagrams are not yet available in the renderer, however they will be added soon. Member force and moment envelope reports can now be limited to the maximum and minimum values taken from just one end of the members rather than from both ends. The analysis engine has also had a major make-over with finite and large displacement theory added, plus options for secant or tangent matrix solutions, residual or full loading, and residual convergence criteria. An "Auto" optimizer setting has also been added that senses the most efficient optimization method before the main analysis calculations begin. It removes the necessity for you to manually use trial and error methods to find the best optimization setting. The standard libraries have been completely re-designed allowing non-standard and built-up sections to be saved. A new shape builder, moving loads generator with animated moving loads, and area loads generator have also been added. Other major new features include on-screen notes, job attachments, dimensions, load combinations grid, load case titles viewer, measure tool, textures, gridlines, view selector, customizable toolbars and multiple undo/redo steps. The major new features of SPACE GASS 11 are listed in more detail below:  A new renderer with full editing capabilities. 

A new shape builder with shape dragging, snapping, stacking, alignment and copy/paste. Shapes can now be specified as voids to easily model holes in your sections. New standard shapes have also been added for polygons,

15

SPACE GASS 12 User Manual polytubes, triangles, Cees, Zeds, tophats and schifflerized angles. Line shapes that allow you to specify a line thickness and a series of points have also been added. You can even show the dimensions of your sections graphically in the new shape builder.

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

On-screen notes that can be positioned anywhere on or near your model or attached to nodes, members or plates.



Dimensions that can be added to your model or to individual members or plates.



A measure tool that lets you determine the actual length, component lengths and angles between any two points.



An attachment tool that you can use to attach external documents, spreadsheets, drawings or any other files to your SPACE GASS job and embed them into the job file.



Important new drawing aids now let you align with other existing points or objects, snap to key intermediate positions along members, attach to existing objects, or align with existing members or global axes. You can even lock onto a node or member by briefly hovering over it and then begin drawing at some offset away from it. When aligned with an axis, member or point, you can also just type in the desired distance away your point should be.



A new combination load cases grid showing primary and combination load cases across the top and combination load cases down the side. You simply type multiplying factors into any cells to quickly build up your combination load cases in a very visual way. Rows for new combination load cases can be added as desired.



Customizable toolbars.



A view selector showing the current viewpoint. It can also be dragged around or clicked to change the orientation of the model.



Unlimited undo/redo steps.



More detailed infotips when hovering over a node, member or plate.

Introduction 

New libraries in XML format that now hold non-standard and built-up sections, directly editable via the shape builder and/or library editor. Categories have also been added for Common, Special, Legacy and Obsolete classifications.



A new moving loads generator incorporating animated views of the vehicles travelling over your model. Horizontal loads and moments can now be added to vehicles. Travel paths can now be drawn graphically, as can a loading area outside of which wheels are treated as inactive even if they are still within the ends of their travel path. A new vehicle editor has also been added, and vehicles are now incorporated into the standard libraries.



A load case manager now lets you copy, renumber or delete multiple load cases rather than one at a time.



buttons throughout SPACE GASS that allow to select from load cases, sections or materials that already exist in the job, plus a load case titles viewer that can be left open all the time if you need to see which load cases are which.



A new area loads generator with options for two-way and one-way loads. Load directions include X, Y, Z, "Normal to area" and "Vector". Loading areas can be actual or projected, and more than four members per polygon can now be handled.



A new renumbering tool that offers renumbering in three directions simultaneously.



A taper/haunch tool that now subdivides automatically if required.



A new find tool with additional modes for finding duplicated nodes, invalid plates, members duplicated in steel member groups, members with free ends and plates with free vertices.



New move, rotate, copy, mirror, stretch and scale tools that allow you to select nodes, members or plates. They also provide a graphical preview of the final result before the changes are made.

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18



Textures such as "brickwork", "steel" and "concrete" that can be added to members or plates and shown graphically.



Gridlines that can be defined and shown graphically in two directions at any spacings and then used as snap and reference points when drawing objects or locating points.



A tool for converting static loads such as dead loads and live loads into masses for use in a dynamic analysis.



A new curve editor for spectral curves that has extra capabilities for importing, exporting, labelling and an equation data generation tool.



A view manager that lets you save the current view into a list of saved views and then recall them as desired.



Moveable property panels that list all of the sections and materials used in your model. You can even click on a section or material in the panel to select all the members or plates in your model that use that item.



A member alignment tool that lets you align or stack members via their center, top, bottom, left or right sides.



An option for showing member origins graphically. This quickly lets you see which way each member is running.



Generation of bends of any radius at member intersections. A very useful tool for pipework analysis.



A tool for reversing the direction of members. Options for adjusting member fixities, offsets and loads are included.



Various tools for extending members along their length, moving intermediate nodes, removing intermediate nodes and removing crossed member nodes.



A new steel member design module for the Hong Kong code HK CP2011 has been released.

Introduction Version 10.8  Steel member design modules for the AISC 360-10 LRFD and ASD standards have been released. 

SPACE GASS now uses the Titan license manager softlock system instead of hardware locks, although hardware locks can still be supplied if requested. TitanLM suppports stand-alone or network installations, and lets users borrow licenses from the network for use off-site.

Versions 10.6 to 10.7  A new plate element has been added in v10.7. Plate elements can be quadrilateral or triangular with bending, shear and membrane stiffness. 

SPACE GASS can now import and export data in CIMSteel/2 (CIS/2) and IFC Step file formats. This allows it to communicate directly with many other programs such as Tekla Structures/XSteel, ProSteel, Microstation, Frameworks Plus, AutoCAD, Revit Structure, StruCAD, etc.



A new built-in graphics rendering module has been added in v10.7 that allows you to generate realistic rendered models of your job that show the complete geometry of all members and plates. This replaces the old internal 3D viewer and the external VRML viewer. It is expected that this module will gradually be given full input, editing and viewing functionality until it completely replaces the existing graphics system in SPACE GASS.



Nodes can now be moved, rotated or deleted directly in v10.7.



Rotated and/or flipped members can now be located using the find command or filtered in v10.7.



In v10.7 graphical envelopes can now be limited to minimums and maximums, just minimums, just maximums or just absolute maximums.



The minimum and maximum intermediate values are now shown on displacement, bending moment, shear force, axial force, torsion and stress diagrams in v10.6.



A new connectivity tool has been added that allows you to check what is connected to any given node, member or plate.

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SPACE GASS 12 User Manual Versions 10.1 to 10.5  An interface to Autodesk’s Revit Structure program has been added in v10.51b.

20



The dynamic response analysis module now supports AS1170.4-2007 and NZS1170.5-2004



Dynamic zoom, pan, viewpoint and diagram scale changing have been added in v10.50. Your current operation stays active and none of your node, member or plate selections are lost while you are using these tools. Refer to shortcuts for more information.



SPACE GASS can be run minimized, normal or maximized (the default mode) depending on the -min, -nml or -max command line options. It can also be controlled by the SHOW line in a script file. These changes were made in v10.50a.



The concrete material properties in the standard metric library have been updated in v10.50a. The new values are based on AS3600-2001 clauses 6.1.5, 6.1.6 and Commentary Table C6.1.2.



Importing/exporting MS-Excel, MS-Word or MS-Access data can now be done in script mode in v10.50.



"D" restraints are no longer supported in v10.50. Restraints are now just "F", "R" or "S".



The structure wizard no longer generates general restraints and is less restraining in general in v10.50.



Importing of SDNF version 3 files is now supported in v10.50.



A new steel member design module for the Hong Kong code HK CP2005 has been added in v10.41.



A new steel member design module for the British code BS5950:2000 has been added in v10.41.



When exporting to DXF, the frame data can now be put into sectionspecific layers rather than having the entire frame in one layer.

Introduction 

A new steel member design module for the LiteSteel beam range of sections from Smorgon Steel has been added in v10.40. These are designed to AS4600.



The tool that updates analysis section property data based on the results of a steel member design has been enhanced considerably so that it allows the update-analysis-design procedure to be iterated automatically.



A new dynamic frequency analysis solver has been added in v10.30. It allows you to create combinations of mass load cases and to combine lumped mass load cases with self weight load cases. The new solver uses the wavefront optimizer and, as a result, the computer’s memory requirement is vastly reduced.



An option for SPACE GASS to check for program updates via the SPACE GASS website has been added.



The moving load generator is now able to generate combination load cases that combine the moving loads with other static loads.



Moving load travel path coordinates, when used in conjunction with travel path node numbers, are now treated as offsets from the path defined by the node numbers.



The number of moving load wheels per vehicle has been increased to 200.



Custom libraries are now stored in a separate file to the standard libraries. They can also be stored in a different folder to the standard libraries.



Your company logo can now be scaled to an exact height that you specify and can optionally be included on every page or just the first page. JPG images formats are also now supported.



Saving of loads after graphical editing, importing of text files and report generation have all been sped up dramatically.



Zooming via the mousewheel is now centered on the mouse position.



Selection of the local XY and/or XZ planes for the display of moments, shears and stresses can now be made direct from the side toolbar rather than via a filter.

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SPACE GASS 12 User Manual 

New members being drawn graphically can now be optionally given the default attributes or those of the previously accessed member.



An option for allowing duplicate members to be drawn has been added. Finding and filtering duplicate members has also been added to the cleanup, find and filter functions.



Deleting members with zero length has been added to the cleanup function.



Filters defined in terms of analysis members now also affect steel design reports.



Options for suppressing automatic re-scaling of load and analysis results diagrams have been added.



An option for selecting steel members and connections graphically and then viewing or editing them in a datasheet has been added.



The default bolt, plate, weld, rebar, spectral and vehicle library names can now be specified in the configuration.



The lowest buckling load factor is now displayed at the end of a buckling analysis.



The end offset distance for members exported to a DXF drawing file can now be specified.



The data generated by the structure wizard is now adjusted according to the vertical axis setting.



The default gravity direction in the self-weight datasheet is now adjusted according to the vertical axis setting.



Auto-created steel members are now terminated at pin-ended members.

Version 10.00  A facility for generating moving loads has been added. 

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Other jobs can be opened and merged with the current job.

Introduction 

Steel member design input data can now be generated automatically for the entire model.



A facility for connecting members that cross over each other has been added.



Print previews can be produced.



Your company logo can be included in text and graphical reports.



The analysis and design output has been combined into a single report.



Text reports can be exported to PDF, HTML and TXT files.



Graphical output can be exported to PDF, HTML and BMP files.



All symbols are now shown correctly in reports.



A new page setup form gives you full control over the output device, margins, page layout and formatting.



You can specify and configure separate graphics and text printers.



USB network locks are supported.



If the program is terminated abnormally, any network licences that were active are recovered immediately and automatically.



Mouse wheel zooming, panning and viewpoint changing is supported.



Keyboard zooming, panning and viewpoint changing is supported.



Keyboard scrolling through filters, views and load cases is supported.



Temporary job files are now stored on the local workstation for extra speed and much reduced network traffic.



Filters, views, etc. in the current job can be retained when data is imported from a text file.

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24



In order to detect the cause of frame buckling, the nodes at which the maximum translations and rotations occur are listed in buckling reports.



Tension/Compression-only effects can be made to revert to "no reversal" mode after a specified number of iterations.



Unrestrained degrees of freedom are now automatically stabilised during the analysis. This prevents many instabilities due to incorrect modelling.



Cable members no longer require uniformly distributed loads to be applied to them.



Nodes connected only to cable members no longer have to be restrained rotationally.



Error messages can be printed or copied to the clipboard.



Export files include all input data and are no longer affected by filters or report selections.



You can print or obtain print previews direct from the datasheets.



SPACE GASS can now import and export data directly with MS-Excel, MS-Access and MS-Word.



Options for springs and compression-only members have been added to the structure wizard beam and grillage structures.



Compression effective lengths in the steel member design input data can be fully controlled separately for each axis.



The automatic reduction of the minor axis compression effective length due to flange restraints is now optional.



Steel members can be nominated as "braced " for either or both axes in order to limit the compression effective lengths to their actual lengths.



Double angles are shown as such in the graphical section property legend.



Steel members that have been offset can now be designed.

Introduction 

Everything attached to and associated with a member is deleted when the member is deleted. This includes attributes, offsets, loads and design input data.



The steel design input data member lists are automatically adjusted when members are deleted, subdivided or otherwise edited graphically.



Steel members and connections are now sorted numerically if input or edited graphically.



Abandoned unnamed jobs can now be recovered automatically.



Undo for all design input data is supported.



Undo for node, member and plate renumbering is supported.



Cleanup for all design input data is supported.



The area loader supports subdivided members.



Single angle sections can be designed as concentrically connected.



The properties of a node can be copied to a graphical selection of other nodes.



The properties of a member can be copied to a graphical selection of other members.



The design input data for a steel member can be copied to a graphical selection of other steel members.



Loads can be copied from a node to a graphical selection of other nodes.



Loads can be copied from a member to a graphical selection of other members.



You can press the space bar to repeat the last graphics command.



An external macro such as another program, batch file or MSExcel/Access macro can be run from within SPACE GASS.

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

SPACE GASS can be controlled externally from another program or batch file using a script file.



A backup copy of the job is made just before each save.



Full 3D geometry displays can be saved in VRML files for later viewing.



Buttons have been added to the library editor for adding, deleting and editing.



A large number of minor improvements, bug fixes and adjustments have been incorporated.

Installation and Configuration Installation and configuration Installation and configuration of SPACE GASS is a simple two-stage process that is explained in the following sections.

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Installing SPACE GASS The installation procedure involves downloading and installing SPACE GASS on your computer and then registering it for the modules you are licensed to use. The registration procedure also involves linking SPACE GASS to your specific Titan softlock or hardware lock. For detailed instructions, refer to www.spacegass.com/install.

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Configuring SPACE GASS You can run SPACE GASS by double-clicking the SPACE GASS icon which has been created. When you first start SPACE GASS, or if you make any changes to your system, you will be prompted for some configuration information. After the initial configuration, you can change any of the configuration settings by selecting them from the Config menu. The eight configuration forms are detailed in this chapter. All configurable data is stored in a number of files called SG.INI, SGSettings.GS and various XML files. They are all stored in the LocalAppData folder (eg. c:\Users\Fred\AppData\Local\SPACE GASS\12). Note that you can quickly reset SPACE GASS back to its default configuration settings by running the SPACE GASS Utility Tool (via the Start button => All Programs => SPACE GASS 12 => Tools => SPACE GASS Utility) and clicking the "Reset Client Configuration" button or the "Reset All" button. For more information, refer to The SPACE GASS utility tool.

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Folders and files Select "Folders and files" from the Config menu. This form allows you to set the folder locations for the SPACE GASS program itself and for the various types of data files.

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Installation and Configuration Main program folder Contains the SPACE GASS program itself. Main data folder Contains the main job data files. Standard libraries folder Contains the standard section, material, bolt, plate, weld, spectral curve, reinforcing bar and vehicle libraries supplied with SPACE GASS. This normally matches the main program folder, however it can be different if you wish to have the standard libraries in a separate folder. Note that all standard libraries are contained in a file called sglibstandard.mdb which cannot be modified. Custom libraries folder Contains the custom section, material, bolt, plate, weld, spectral curve, reinforcing bar and vehicle libraries that you create. These can be in the same folder as the standard libraries or in another location. Note that all custom libraries are contained in a file called sglibcustom.mdb which can be modified via the library editor or the shape builder. If you wish to have the SPACE GASS program folder write protected then you must change the custom library folder to a different location. Text data folder Contains import/export text data files and print text files. Backup data folder Contains import/export backup job data files. Archive data folder Contains import/export archive data files. CAD data folder Contains import/export CAD data files. Temporary data folder Contains temporary files that are created and deleted by SPACE GASS as it operates.

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SPACE GASS 12 User Manual Documents folder Contains MS-Access, MS-Excel and MS-Word document files. Text editor program The name of the SPACE GASS text editor. This can be the standard Windows NOTEPAD or any other text editor that runs in Windows. Calculator program The name of the SPACE GASS calculator. This can be the standard Windows calculator or any other calculator that runs in Windows. Default library names The names of the default libraries. Note that any folders that do not exist are automatically created as you go. Copy the Job to the Backup Data Folder Before Saving If this box is selected, whenever a job is saved, a copy of the previously saved version of the job is copied to the backup data folder and renamed with an extension of BAK.

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Text formatting Select "Text formatting" from the Config menu. This form allows you to set the report and graphics text formats and fonts.

Report text format The report text format which is initially selected when you create a new job. Note that this setting does not change the current job. The report text format for the current job can only be changed from the report form (selected from the Output menu). Graphics text format The graphics text format which is initially selected when you create a new job. Note that this setting does not change the current job. The graphics text format for the current job can only be changed from the Labelling and Annotation form (selected from the View menu). Report font The font for text reports. This must not be a proportional font otherwise the columns of numbers in reports will not line up properly. The two-column output toggle switches between one-column and two-column output in the report.

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Screen graphics font The font for screen graphics text. This can be any proportional or fixed font. After setting the screen graphics font size, if the text on the SPACE GASS graphics screen looks too big or too small, it may be because the screen graphics correction factors have not been set correctly. Refer to "Graphics scale calibration" in "Graphics scale calibration" later in this chapter. Printer graphics font The font for printer graphics text. This can be any proportional or fixed font.

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General configuration Select "General configuration" from the Config menu. This form allows you to set the general purpose configuration items in SPACE GASS.

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SPACE GASS 12 User Manual Sound on alert This allows you to suppress or enable the sound that the program makes when it wants to alert you to something. Sound on error This allows you to suppress or enable the sound that the program makes when an error occurs. Diagram shading Loading, bending moment, shear force, stress and axial force diagrams are shaded if this item is checked. Shading is normally turned off as it makes multiple superimposed diagrams hard to read. Check disk space If this item is checked, SPACE GASS performs a disk space check to ensure that there is enough free space for a static or dynamic analysis to proceed to completion. If the disk space check has been disabled and there is not enough space for the analysis data, the program may abort with an error message. Although this is not a desirable occurrence, it will not result in loss of data. Vertical axis The graphics vertical axis which is initially selected when you create a new job. Note that this setting does not change the current job. The graphics vertical axis for the current job can only be changed from the Viewpoint form (selected from the View menu). Changing this setting only affects the graphics display. It doesn’t affect the local axis definitions, the steel design top flange definitions, or the analysis and design modules in any way. Aperture size The size of the aperture circle which appears when nodes and/or members can be selected graphically. Crosshair size The size of the crosshair which appears when snap or ortho modes are on. Curve resolution All curved lines drawn with SPACE GASS are actually a series of short straight lines. In most cases it is very difficult to differentiate between a true curve and a

36

Installation and Configuration series of ten straight line segments placed around the curve. SPACE GASS allows you to specify how many straight line segments per member are used to approximate curved lines in displacement, bending moment, shear force or axial force diagrams. Use previous attributes when drawing new members If this item is checked, any new members that you draw will have the same attributes as the member that was previously drawn or edited graphically. If unchecked, newly drawn members will have the default attributes. Allow duplicates when drawing new members Check this item if you wish to be able to draw multiple members between the same two nodes. For example, you may wish to have two members that share the same end nodes but which are offset away from each other by some distance. This may be applicable for double angle members that have a gap between them. If you have drawn duplicate members and wish to locate them, you can do so by using the Find tool and selecting "Duplicated" in the member type field. You can also use a similar procedure to create a filter that isolates any duplicated members. Re-scale load diagrams after load editing If this item is checked, load diagrams will be re-scaled automatically whenever any distributed member loads are changed. Re-scale result diagrams after analysis If this item is checked, the analysis diagrams will be re-scaled automatically whenever an analysis is completed. Draw positive bending moments on tension/compression side The convention for drawing bending moment diagrams varies from country to country. SPACE GASS can be configured to draw bending moments on either the tension or compression side of a member. Shorten members in DXF files When exporting to a DXF file, you can allow the members to be drawn full length or you can have them shortened at each end by a proportion of the member depth. For example, a member with a depth of 500mm could be drawn 250mm shorter at each end by using a depth factor of 0.5. Dashed lines Dashed (broken) lines are used to differentiate between load cases and between diagram types. All lines are drawn continuous if dashed lines are not allowed.

37


DXF layer names Layer names are only applicable if you have the CAD interface module. These are the layers into which the drawing will be placed when you transfer it into your CAD program. It is recommended that you make each layer name different so that it is easy to distinguish between centrelines, text, members, hidden lines, attributes, bolts, plates and cut-off lines. It is also recommended that you set the hidden line layer in your CAD software to dashed or dotted lines. Automatically check for program updates SPACE GASS can automatically check its website to see if a newer version is available. If so, a notification message is displayed and you have the option of downloading and installing the update.

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Graphics scale calibration Select "Graphics scale calibration" from the Config menu. This form allows you to calibrate your monitor so that graphics is properly sized and proportioned.

Some monitors exaggerate the horizontal and/or vertical scales so that the SPACE GASS graphical output appears stretched or compressed in either or both directions. SPACE GASS allows you to apply correction factors which allow for these exaggerations and adjust the graphical output so that it is correctly sized and proportioned. You should simply measure the width and height of the two lines on the screen with a ruler, and SPACE GASS calculates the correction factors for you. ! IMPORTANT NOTE ! Ensure that you measure between the arrow heads rather than measuring the overall form or screen size, otherwise items on the SPACE GASS graphics screen will appear too small or too large.

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Graphics colors Select "Graphics colors" from the Config menu. This form allows you to select colors for screen, printer and plotter graphics output.

Colors are selected by first clicking the item to be changed and then selecting a color from the palette at the bottom of the form.

40

Installation and Configuration The list of color indexes next to "Section properties" represents section properties 1-25. If you have more than 25 section properties, the pattern is repeated for properties 26-50, 51-75, etc. The list of color indexes next to "Load cases" represents the first 25 load cases. If you have more than 25 load cases, the pattern is repeated for each additional group of 25 load cases.

41


General colors Select "General colors" from the Config menu. This form allows you to set the Windows color scheme. It controls items such as form colors, button colors, scroll bar colors, etc.

When you select this option SPACE GASS loads the standard Windows color selection form which can also be selected from the Windows Control Panel. The appearance of this screen is dependant upon the version of Windows you are running.

42


Problem size limits Select "Problem size limits" from the Config menu. This form allows you to set maximum job size limits.

SPACE GASS has been dimensioned dynamically. This allows it to expand into the available memory of your computer giving you virtually unlimited problem size capacity dependant only on the memory capacity of your computer. The size limits you set allow you to reserve space for a job, with space being allocated according to the size of each component of a job. You should set the limits high enough so that there is enough capacity for the largest of jobs that you are likely to encounter but small enough that you don't exceed the memory capacity of your computer. Keep in mind that the limits can be changed at any time, even when you are halfway through inputting a job and find that you have run out of capacity. Just select "Problem size limits" from the Config menu and change the limits to suit your job size. After changing the limits you can simply return to where you left off, with all previously entered data retained.

43


Renderer configuration Various renderer settings and preferences are available from the Settings menu in the renderer as shown below. In the following form: The "Alignment proximity" controls how close the mouse cursor must be to an axis aligned with a "locked on" node or member or a global axis in order to align with it. The "Cursor pickbox size" controls how close the mouse cursor must be to a node, member or plate in order to select it, lock onto it, or display its infotip. The "Lock delay" controls how long the mouse cursor must be near a node or member before you lock onto it.

In the following form: The "Use previous attributes..." option, if ticked, means that when you draw a new node, member or plate it will have the same properties (ie. section ID, material ID, etc) as the previous item you drew or selected.

44

Installation and Configuration The "Allow duplicates..." option lets you draw members or plates on top of existing members or plates (ie. so that they share the same nodes). The "Allow hidden nodes to be selectable" option allows you to select nodes that you can't see due to being behind other objects. The "Curve quality" controls the smoothness of curved elements such as 3D nodes, members with circular cross sections, etc. A higher curve quality makes the renderer slightly slower and more memory hungry. The "Result quality" specifies how many short straight lines are used to approximate a curve when drawing deflected shapes, bending moment diagrams, etc. The "Highlight delay" controls how long the mouse cursor must be near a node, member or plate before it becomes highlighted. The "Infotip delay" controls how long the mouse cursor must be near a node, member or plate before its infotip appears. The "Maximum load cases shown together" is the maximum number of load cases that will be displayed simultaneously if you select "All load cases", "All primary load cases" or "All combination load cases". It is used to prevent memory overflow problems when many load cases are displayed together. Note that this setting is ignored if your model has less than 500 nodes. The "Rotation drag distance" is the number of pixels that you can move the mouse while the left button is held down before it will start to rotate the model. It is used to avoid the problem of the model rotating unintentionally when you are trying to select items or start a selection window. If this problem occurs then try increasing the rotation drag distance slightly. The "Rotation mode" controls how the model behaves when you rotate it with the mouse. Trackball mode lets the model rotate about all three axes, whereas Turntable mode prevents rotation about an axis normal to your computer screen. Trackball mode is a bit harder to control than Turntable.

45


In the following form you can change the theme of the renderer via the "Skin" setting. This affects the colors and styles of all the forms, buttons and input fields. You can also separately change the colors of most the items in your model to suit your requirements.

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47


Customizing toolbars All of the toolbars in the renderer can be hidden/shown, moved or undocked. Buttons can also be added or deleted.

In order to move or undock a toolbar, simply drag its handle on the left hand end of the toolbar to the desired location.

Undocked toolbars such as the one shown below can be placed anywhere in the renderer window or docked to the top, bottom, left or right sides of the renderer.

To hide a toolbar, simply right-click anywhere on it and then untick it from the list of toolbars that appears. To restore a toolbar, select Toolbars from the Window menu, click the Toolbars tab and then tick the desired toolbar.

48


Adding or deleting buttons To add or delete buttons, right-click anywhere on a toolbar, select Customize from the menu that appears and then click the Commands tab.

You can then select a toolbar from the list and add or delete buttons as required.

49


The Options tab also has additional settings that you might find useful as shown below.

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For information on how to customize the renderer's property panels, refer to Customizing property panels.

51


Customizing property panels Property panels can be pinned open by clicking the button at the top of the panel so that it changes to . If you click it again, it changes to , indicating that the panel is not pinned and will slide closed as soon as you move away from it. By dragging the title bar of a panel you can drag it away from the side of the renderer and place it anywhere on the screen or dock it to the left or right side of the renderer. You can also split the property panels into separate node, member and plate panels by dragging the relevant tab at the bottom of the panels.

52


For information on how to customize the renderer's toolbars, refer to Customizing toolbars.

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54


The SPACE GASS utility tool The utility tool lets you reset the SPACE GASS registration and/or configuration settings, or attach your own logo to SPACE GASS so that it appears in the printed reports.

Reset Registration If you have a Titan softlock, this option resets SPACE GASS back to its freshly installed state. It is used primarily to start afresh in cases where SPACE GASS is having difficulty obtaining a Titan license. Note that this option resets the connection from SPACE GASS to the Titan server but does not affect the Titan server itself or its registration. If you have a hardware lock, this option de-registers SPACE GASS. The next time you run SPACE GASS it will initiate the re-registration process. It is used primarily to re-register SPACE GASS in cases such as when new modules have been purchased or when the hardware lock has been changed. For more information, refer to http://www.spacegass.com/install.

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SPACE GASS 12 User Manual Reset Client Configuration This option resets the SPACE GASS client configuration back to its default settings. The next time you run SPACE GASS it will initiate the re-configuration process. For more information, refer to Configuring SPACE GASS. Reset All Choose this option to reset both the registration and client configuration. Set Report Logo You can use this option to set your own logo to appear at the top of your printed reports. You must first create a JPG image file that contains your logo and any text that goes with it. For best results, make the image file large enough so that it contains enough pixels for a printer resolution of at least 300 dpi. For example, if your printer operates at 600 dpi resolution and you want the printed logo height to be 20mm, your image file will need to be at least 472 pixels in height (ie. 600/25.4x20). Regardless of the size of your image file, it will be scaled to print at the exact height you specify in the page setup form. After creating your JPG image file, click the "Set Report Logo" button to display the following form.

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You should then click the "Set Logo" button, browse to your image file and select it. Note that even after completing the above procedure, you must ensure that SPACE GASS is configured to use the logo. You can do this by choosing "Page Setup" from the SPACE GASS File menu, setting the logo height and specifying whether it is to be on the first page only or on all pages. For more information, refer to Page setup.

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Getting Started Getting started This chapter explains how to start SPACE GASS and takes you on a guided tour of the main SPACE GASS window and all of its menus. It also explains how you should interact with SPACE GASS and respond to its requests for data.

59


Starting SPACE GASS Before proceeding with this section you should have copied and installed SPACE GASS (see also Installing SPACE GASS). In order to start SPACE GASS, you can either: 1. 2.

Double-click the "SPACE GASS" shortcut on your desktop. Double-click on a SPACE GASS job file (they end with .SG).

If you are running SPACE GASS for the first time, you will be taken through part of the SPACE GASS configuration program (see also Configuring SPACE GASS). You can control how SPACE GASS starts by the use of command line options. For example, you can bypass the splash screen, you can prevent the previous job from loading automatically, you can control the location of the SPACE GASS configuration file, etc. They are fully explained in Command line options.

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Getting Started

Command line options You can control how SPACE GASS starts by adding one or more options to the command line in the shortcut you use to start SPACE GASS. To add a command line option, select "Properties" of your SPACE GASS shortcut and append the contents of the "Target" field with one or more of the following options. -n

Bypasses the automatic loading of the previously used job.

-p

Bypasses the splash screen.

-w

Bypasses the Internet check for new versions of SPACE GASS.

-c [bbggrr]

Allows you to set the datasheet alternate line color, where [bbggrr] is the 6 character hexadecimal representation of the desired color with bb=blue component, gg=green component and rr=red component. For example, 50% blue, 50% green and 20% red could be specified with a command line option of c7f7f33.

-s [file]

Allows you to specify a script file that contains a list of menu commands and other items that SPACE GASS will automatically execute one-by-one rather than you operating it in the normal way. For example, a command line option of -s "c:\scripts\myscript.txt" would load the myscript.txt script file from the c:\scripts folder. Note that the ""s can be omitted if this option is at the end of the target field. See "Running a script" for more information and full details of the script file format.

-min

Runs SPACE GASS minimized so that it is not visible except for an icon on the taskbar. This can be useful when SPACE GASS is controlled by a script file (see the -s command line option above), although it may be more convenient to use the "SHOW MIN" command in the script file to achieve the same effect. See "Running a script" for more information and full

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details of the script file format. -nml

Runs SPACE GASS in a normal window that is usually smaller than the overall screen size.

-max

Runs SPACE GASS maximized so that it fills the entire screen area. This is the default setting and is the same as if none of the -min, -nml or -max command line options are specified.

Note that the -min, -nml and -max command line options can be overridden by the SHOW line in a script file. See "Running a script" for more information and full details of the script file format. For example, to bypass the splash screen and the automatic loading of the previously used job, you could have a shortcut target field of: "C:\Program Files\SPACE GASS\Exe\sgwin.exe" -p -n If you start SPACE GASS by double-clicking on a job, then the shortcut is bypassed and any command line options in it are not used. You can, however, apply the command line options when a job is double-clicked by starting Windows Explorer, selecting Tools –> Folder Options from the menu, clicking the File Types tab, scrolling down to and clicking the SG file extension, clicking the Advanced button, clicking the Edit button and then adding the command line option to the end of the "Application used to perform action" field. Note that you can use the -i command line option to set up multiple shortcuts, each with its own SG.INI file for cases where you want to be able to run SPACE GASS with different configurations. For example, you may have a laptop that is normally connected to the office network during which SPACE GASS needs to access jobs and libraries that are stored on the network. However, there may also be times when the laptop is being used away from the network on-site or at home. It would be convenient if these two scenarios could each have its own folder settings and other configuration items. You can set this up by simply making a copy of your SPACE GASS shortcut so that you have a shortcut for when you are connected to the office network and another for when you are running SPACE GASS away from the office, each with its own SG.INI file and configuration settings. Edit the properties of each shortcut and add -i "path" to the end of the target field, where "path" is the folder containing the

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Getting Started SG.INI file. For example, -i "c:\SG\Config\Office" would store the SG.INI file for that shortcut in the "c:\SG\Config\Office" folder, and -i "c:\SG\Config\Home" would store the SG.INI file for that shortcut in the "c:\SG\Config\Home" folder. The next time you run SPACE GASS from either shortcut, it would run through the configuration process and let you set them up with their own unique configuration settings.

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The main SPACE GASS window When you start SPACE GASS, the following main window appears with the structural model for the current job displayed in it. You can also click the button to open the renderer window.

The title bar This is the colored band across the top of the window, it contains the SPACE GASS version, the name of the current job and the scale of the viewport if it is being displayed in full-screen mode. The menu bar The second band across the top of the window contains the twelve main menu items. By selecting one of the main menu items you can gain access to all of the options contained within that menu. The menu bar allows you to access all of the program’s features (see also The menu system).

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Getting Started The toolbars The buttons across the top and to the left of the display area form the toolbars. The toolbar buttons replicate the most commonly used menu items and give you instant access to them (see also The toolbars). The graphics settings buttons across the bottom of the screen display the current settings for the drawing tool and allow the settings to be toggled. The graphics display area The area in the centre of the main window displays the structural model for the current job. The global axes are also shown in the top-right corner. You can display up to four viewports in this area. The text display area The area below the graphics settings buttons forms the text display area. The first line displays the project heading, job heading and the local axis settings. The second line is a multi-purpose line which usually contains the status line, but which also periodically displays other prompts and messages, some of which are purely informative and some of which require you to respond.

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The status line

The status line appears in the second line of the text display area of the main SPACE GASS window. It is also displayed at the bottom of the renderer. The status line indicates which data is present for the various parts of the current job. The presence (or absence) of data is indicated by sequences of characters shown as follows. In all cases, unless otherwise indicated, "Y" represents "data exists", while "N" represents "no data exists". If, for example, you have performed a static analysis, a dynamic frequency analysis and an elastic buckling analysis (but no dynamic response analysis), the "Analysis" part of the status line would appear as "Analysis:YYNY".

You can use the status line as a check to ensure you have entered sufficient data before performing another operation. For instance, you cannot perform a static analysis until you have applied some type of load to the structure (in addition to which, sufficient data must be present on the structure itself). Check for the appropriate code in the status line window before proceeding with the operation. Headings 1. Project name, Job name, Designer’s initials and Notes (Y/N) Structure 1. Nodes 2. Members 3. Plates 4. Restraints 5. Sections 6. Materials 7. Master-slave constraints 8. Member offsets (Y/N)(Y/N)(Y/N)(Y/N)(Y/N)(Y/N)(Y/N)(Y/N) Loads

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Getting Started 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13.

Node loads Prescribed node displacements Member concentrated loads Member distributed forces Member distributed torsions Thermal loads Member prestress loads Plate pressure loads Self weight Combination load cases Load case titles Lumped masses Spectral load data

(Y/N)(Y/N)(Y/N)(Y/N)(Y/N)(Y/N)(Y/N)(Y/N)(Y/N)(Y/N)(Y/N)(Y/N)(Y/N) Analysis 1. Static analysis, where "N"=not analysed, "Y"=analysed, "U"=desired convergence not obtained, "I"=ill-conditioned 2. Dynamic frequency analysis, where "N"=not analysed, "Y"=analysed 3. Dynamic response spectrum analysis, where "N"=not analysed, "Y"=analysed 4. Buckling analysis, where "N"=not analysed, "Y"=analysed (Y/N/U/I)(Y/N)(Y/N)(Y/N) Steel 1. Steel member design data 2. Steel Member design/check results, where "N"=not designed or checked, "D"=designed, "C"=checked 3. Connection design data

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SPACE GASS 12 User Manual 4. Connection design results, where "N"=not designed, "D"=designed (Y/N)(D/C/N)(Y/N)(D/N) Concrete 1. Concrete column design data 2. Concrete beam design data (Y/N)(Y/N)

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Getting Started

Using the mouse This section gives basic information about using the mouse. If your mouse has more than one button, use the left button unless specifically told otherwise. The right mouse button is generally used by SPACE GASS to replicate the keyboard ESC key. The ESC key generally enables you to abort from the current operation or form. Note, however that the right mouse button is not always active, such as when a form is open. The following definitions explain the basic terms that are associated with using the mouse. Pointer The descriptive cursor that appears on the screen and tracks the mouse movement. Point Position the pointer on an item. Click (or Pick) Point to an item, and then quickly press and release the left mouse button. Right Click Point to an item, and then quickly press and release the right mouse button. Double-click Point to an item, and then quickly press and release the left mouse button twice. Drag Point to an item, press and hold the left mouse button as you move the mouse to a new location, then release it. Mousewheel Rotate the mousewheel to dynamically zoom, pan or change the viewpoint. For more information, refer to Shortcuts.

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Dialogue boxes When you choose a command, a form often appears so that you can select options or type in data. If an option is dimmed, it is not currently available.

Using the keyboard with a form Although it’s usually easiest to use a mouse while you work in a form, you can also select options or fill in information with the keyboard. Some of the standard keyboard operations that you can use in forms are as follows. TAB SHIFT+TAB ENTER ESC ALT

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Move to the next field in the form. Move to the previous field in the form. Equivalent to selecting the Ok button. Equivalent to selecting the Cancel button. If an option, box or button has an underlined letter in its name, you can choose that item by holding down ALT while typing the underlined letter.

Getting Started

Moving a form You can move a form dragging its title bar to the new location. The title bar is the colored band along the top of the form. Closing a form You can close a form by pressing the Ok or Cancel buttons. Alternatively, if the form has a control-menu box at the left side of the title bar, you can double-click on it to replicate the cancel button. If you single click the control-menu box, a control menu appears which also allows you to close or move the form.

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Data entry Forms can contain a wide variety of data entry fields, boxes, options and buttons. Some of the commonly used ones in SPACE GASS are: Command buttons

You choose a command button to initiate an action, such as carrying out or cancelling a command. The Ok, Cancel and Help buttons are common command buttons. In SPACE GASS, they are usually located in the top-right corner of the form. To choose a command button, you can either click on it or press TAB until the button you want is selected, and then press ENTER. Scroll bars Some windows and forms have scroll bars which you can use to view information that does not fit inside the window. If you can view all of the contents of a window or form without having to scroll, the scroll bars may be absent or dimmed to indicate that they cannot be used. Scroll bars have a scroll arrow at each end with a moveable scroll box in between. To scroll through information displayed in a window or form, drag the scroll box to the desired position. To scroll one line at a time, click the scroll arrows, or to scroll continuously, hold a scroll arrow down. To scroll one page at a time, click the scroll bar on either side of the scroll box. Text boxes You can type appropriate information directly into text boxes. Text boxes are generally sideways scrollable so that they can hold more data than can be displayed in the box. Sometimes numeric text boxes have arrow buttons attached to them. These are called "spin buttons" and you can change the number in the text box, without actually having to type anything, by clicking the arrows or holding them down.

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Getting Started When entering data into a text box, you will find that quite often a default value is already displayed there. If a default value is highlighted then as soon as you start typing it will be erased. To edit a default value without causing it to be erased, you can simply click somewhere in the text box or press one of the keyboard ARROW keys before you begin typing. The point where you clicked becomes the insertion point for the new text. If you want to highlight text in a text box, you can simply drag the pointer across the text, or double-click on a word to select one word at a time. Any text that you type will then replace the highlighted text. You can also delete highlighted text by pressing "DEL" or "BACKSPACE". Generally, when you select a text box by clicking on it, its default value does not become highlighted, however if you use the TAB key to get to the text box, its default value does become highlighted. List boxes

Display a list of items in a scrollable window from which you can make a selection. In special circumstances, you can sometimes select more than one item from a list box. Combo boxes Appear initially as a rectangular box containing the current selection. When you select the down arrow in the square box at the right of the selection, a list of available choices appears. If there are more items than can fit in the box, scroll bars are provided.

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SPACE GASS 12 User Manual Radio buttons

Represent a group of mutually exclusive options. You can select only one option at a time. If you already have one option selected, your current selection replaces it. The selected radio button contains a black dot. Check boxes

Represent non-exclusive options. You can select as many check box options as needed. When a check box is selected, it contains an X. Lists Sometimes SPACE GASS will ask you to provide a list of items such as nodes, members or load cases. Lists can be typed in as integers separated by commas or dashes. If, for example, your list was to contain the items 1,2,6,7,8,9,13,14,15 and 20, you could type it in as 1,2,6,7,8,9,13,14,15,20 or as 1,2,6-9,13-15,20. Dashes simply allow you to list a range of numbers. A special type of list is used to input flange restraint positions in the steel member design modules. This list accepts @’s (AT symbol) instead of dashes and can be used to quickly input a number of equally spaced flange restraints. For example, a list containing the following numbers 1.2,2.4,3.6,4.8,6.0,6.6,7.2,7.8,8.4 could be replaced with [email protected],[email protected]. When using a file selection form in which you have to scroll to get to the file you want, you can simply type in the first couple of characters of the file name to automatically scroll it into view.

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Getting Started

Managing job files SPACE GASS jobs end with ".SG". Whenever you run SPACE GASS, it loads and displays the job that you previously had open. The procedures for starting new jobs, opening previously saved jobs, merging jobs, saving jobs, deleting jobs and cleaning up jobs are explained in the following sections.

SPACE GASS jobs are actually ZIP files renamed from {Job}.ZIP to {Job}.SG. You can manually open and view their contents with WinZip, however be careful not to make any changes or SPACE GASS may no longer be able to open them.

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Starting a new job You can start a new job by clicking the the File menu.

toolbar button or selecting "New" from

If you have unsaved changes to the current job file then SPACE GASS will ask you if you wish to save these changes.

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Getting Started

Opening a job You can open a previously saved job by clicking the "Open" from the File menu.

toolbar button or selecting

You will be prompted for the name of the file you wish to open. SPACE GASS, by default, looks in the most recently accessed folder when opening a job.

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Merging jobs You can open another previously saved job and merge it with the current job by selecting "Merge" from the File menu. It is a good idea to save the current job first so that you can recover it if required.

For the job being merged with the current job, you can specify whether you want to include its structural data (required), load data and/or design data. The insertion point is the location at which the (0,0,0) origin of the merged job will be located. The default insertion point will guarantee that no overlapping with the current job occurs. In order to prevent clashing of numbered items, the merged job will be adjusted so that its numbering starts after the highest numbers in the current job. This might prevent some jobs from being merged if there is not enough room between the highest numbers in the current job and the maximum numbers specified in the problem size limits. If this occurs, you could renumber the current job and/or the

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Getting Started merged job before attempting the merge, or you could increase the problem size limits if they are not already at their maximum settings.

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Saving a job You can save the current job by clicking the from the File menu.

toolbar button or selecting "Save"

Saves all changes made to the job. If you have not already created a name for the job (ie. if it is previously unsaved) then you will be prompted for a file name and a location (performs the same function as selecting "save as" from the file menu). "Save As" is similar to "Save", except that the job is saved under a new name that you specify. For example, if you open Job1, make changes to it and then use Save As to save it as Job2, Job1 will be left unchanged while Job2 will be the changed version of Job1.

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Getting Started

Deleting a job You can delete a previously saved job by selecting "Delete Job" from the File menu. Deletes the entire job. Use it with care because the job cannot be recovered after it has been deleted.

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Cleaning up a job You can clean up the current job by clicking the toolbar button or selecting "Clean-up Job" from the File menu or the floating menu.

Cleans up your model by deleting obsolete items or items that are no longer connected to anything. For example, it will remove loads that are applied to non-

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Getting Started existent nodes, members or plates, or section properties that are not being used by any members. It is very useful for quickly removing the causes of many analysis errors. The clean-up tool can also merge nodes that are within a specified distance of one another, transferring members, plates, restraints, loads, etc. from the deleted nodes to the retained nodes. If this action results in a change to the way the structure responds to the applied loads then an error message will be displayed and the clean-up will not proceed. Any pairs of nodes close together that are linked with master-slave constraints will not be merged. Dummy nodes can be removed provided they are not used as direction nodes for members or plates.

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Running a macro You can run a macro by clicking the toolbar button or selecting "Run a Macro" from the File menu or the floating menu. Macros are simply programs external to SPACE GASS that you can run from within SPACE GASS using this tool. They can be MS-Excel or MS-Access programs, DLLs, ActiveX programs, EXE programs or batch files. To run a macro, simply double-click the macro name in the form shown below.

To add a new macro or edit an existing macro, just click the "Add" or "Edit" buttons in the above form and then fill in the details in the following form.

Macro Title is the name of the macro that will appear in the "Run a Macro" form. Macro Type specifies the type of macro that is involved.

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Getting Started Macro File gives the location of the external program that will be executed when you run the macro. This is not required for ActiveX macros. Class Name is the name of the class in an ActiveX macro. Macro Name is the name of the macro in an MS-Excel or MS-Access macro. Parameter is a list of extra parameters that are passed to the macro. Examples of each type of macro are supplied with SPACE GASS and are located in the main program folder.

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Running a script Scripts allow you to run and control SPACE GASS from another program external to SPACE GASS. A script is simply a text file that contains a list of commands that SPACE GASS will automatically execute one-by-one. The script file can be located anywhere, and its name and location must be specified in the command line when SPACE GASS is started. For example, a command line option of -s "c:\scripts\myscript.txt" would load the myscript.txt script file from the c:\scripts folder. Note that the double quotes (" ") can be omitted if this option is at the end of the target field. If you don’t want SPACE GASS to be visible when running in script mode then you can use a "SHOW MIN" line in the script file as described below. You can create a script file manually using a text editor or you can write a program that will create the script file and hence be able to control SPACE GASS automatically. The commands in the script file allow you to select any of the SPACE GASS menu items, however currently only the import, export, analysis and exit functions will bypass their input dialogs when in script mode. All of the other functions will display their normal dialogs and messages and then continue with the script when you have responded to them. Any error messages will be displayed and cause the script mode to be terminated. Any informative messages or warnings will be added to the log file and will not cause the script to pause. If you want to run SPACE GASS normally, ensure that the -s script file option does not exist in the target field of the SPACE GASS shortcut that you use to start SPACE GASS, otherwise SPACE GASS will go into script mode and will execute all the script commands rather than allowing you to control it normally. The structure of a script file is as follows: 1.

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A header line containing "SPACE GASS Script File" must appear before any other command lines.

Getting Started 2.

An optional LOGFILE line can be included between the header line and the first command line. It lets you generate a log file that contains a list of all the menu commands executed from the script file, plus any messages, warnings or errors that might occur while SPACE GASS is running in script mode. It’s format is "LOGFILE Filespec", where Filespec is the path and name of the log file you want to create.

3.

An optional SHOW line can be included between the header line and the first command line. You can use it to specify whether SPACE GASS runs in a minimized, normal or maximized window when in script mode. It’s format is "SHOW MIN", "SHOW NML" or "SHOW MAX". "SHOW MIN" runs SPACE GASS minimized so that it is not visible except for an icon on the taskbar. This is probably the most useful setting for running SPACE GASS in script mode. "SHOW NML" runs SPACE GASS in a window that is usually smaller than the overall screen size. "SHOW MAX" runs SPACE GASS maximized so that it fills the entire screen area. This is the default setting and is the same as having no SHOW line in the script file. Note that the SHOW line overrides any -min, -nml or -max command line options that might have been specified. See "Command line options" for more information.

4.

An optional PAUSE line can be included that allows you to pause the script. It can be useful if your script is not working properly and you want to see what stage it is up to at certain points in the script file.

5.

Command lines must appear exactly as "MENU MM SS [Extra]", where MM is a required 2 digit main-menu number, SS is a required 2 digit sub-menu number, and Extra is an optional list of parameters depending on the command. Extra can be up to 128 characters long and is used only as: (a) the file name when importing or exporting files. (b) the merge option when importing, where M signifies to merge rather than overwrite (eg. M c:\Data\MyData.XLS to merge file MyData.XLS with the current job). If the "M" is omitted when importing then the current job gets overwritten. (c) the type of static analysis, where LIN=Linear, SSF=Small displacement theory/Secant matrix/Full loading, SSR=Small displacement theory/Secant matrix/Residual loading, FSF=Finite displacement theory/Secant matrix/Full loading, FSR=Finite displacement theory/Secant matrix/Residual loading, FTR=Finite displacement theory/Tangent matrix/Residual loading, LSF=Large displacement theory/Secant matrix/Full loading, LSR=Large displacement theory/Secant matrix/Residual loading, LTR=Large displacement theory/Tangent matrix/Residual loading.

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Note that SSF, SSR, FSF, FSR, FTR, LSF, LSR and LTR are all non-linear analyses and are only applicable if MENU 04 02 is used. The above parameters can also be used to set the type of axial force distribution calculation in a buckling analysis when MENU 04 05 is used. (d) the list of load cases to be analysed, where CASES specifies the list (eg. CASES4,6,12-17,23,24 to analyse load cases 4, 6, 12-17, 23 and 24). Note that CASES0 signifies that all load cases should be analysed. (e) the solver type, which can be PARADISE, WAVEFRONT or WATCOM. (f) the optimization method when analysing, where NONE=None, AUTO=Auto, GEN=General, LX=Linear-X, LY=Linear-Y, LZ=Linear-Z, CX=Circular-X, CY=Circular-Y or CZ=Circular-Z. (g) the tension/compression-only effects activation in a static analysis, where TON=Activated, TOFF=Deactivated, TNR=No reversal after n iterations (eg. TNR5 for no reversal after 5 iterations). (h) the number of load steps in a non-linear static analysis, where STEPS specifies the number of steps (eg. STEPS1 for one load step). (i) the maximum number of iterations per load step in a non-linear static analysis, where ITNS specifies the maximum iterations (eg. ITNS10 for a maximum of 10 iterations per load step). (j) the convergence accuracy in a non-linear static analysis, where CNVG specifies the convergence (eg. CNVG99.99 for 99.99% convergence). (k) the lists of steel design groups, section properties and/or load cases when performing a steel member design or check. The lists can be specified as GROUPS, SECTIONS and/or CASES (eg. GROUPS15,12,13,15-20 to export groups 1-5, 12, 13 and 15-20). Note that GROUPS0, SECTIONS0 and/or CASES0 signifies that all items should be included. Note that any analysis or design options not set by you via the Extra parameter are taken to be whatever was used in the previous analysis or design. For example, if you run an analysis of load cases 1,2,3 and 4, and then run another analysis in script mode with the CASES parameter omitted, it will also use just load cases 1,2,3 and 4. 6.

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Comment lines are permitted anywhere in the file provided that they have a "#" before the first non-blank character.

Getting Started 7.

Blank lines are permitted anywhere in the file.

A sample script file follows: SPACE GASS Script File # Create a log file (optional) LOGFILE C:\Space Gass Data\Text\Logfile.txt # Import a text file (Textin.txt) MENU 01 15 C:\Space Gass Data\Text\Textin.txt # Perform a non-linear analysis with Linear-X optimization and tension/compression-only effects activated MENU 04 02 LX TON # Export a text file (Textout.txt) MENU 01 26 C:\Space Gass Data\Text\Textout.txt # Exit SPACE GASS MENU 01 41

Note that when you exit SPACE GASS via a script file, any changes to the current job will be abandoned. If you wish to save the changes then you should include a Save or Save-As command before the Exit command.

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Job status You can display the current status of the job as shown below by selecting "Job Status" from the File menu.

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Getting Started

Shortcuts Many of the menu items can also be accessed using a keyboard or mouse shortcut. Ctrl key shortcuts They are shown in the menus with Ctrl+K or Shift+Ctrl+K after them, where K represents the shortcut key. For example, to operate the Edit Libraries tool you must hold down the Ctrl key and then hit the L key (Ctrl+L). Alternatively, to access the Renumber facility you must hold down the Shift and Ctrl keys together and then hit the R key (Shift+Ctrl+R). Alt key shortcuts Every menu item also has an Alt key shortcut that is represented by an underlined character in the menu item names. If you hold down the Alt key, the underlining appears in the menus and you can then hit the underlined character on the keyboard to select the desired menu item. If there are more than one of the same underlined character in a menu, you can simply hit the underlined character multiple times until the desired menu item is selected. For example, to access the Units form you must hold down the Alt key and then hit the S key followed by the U key (Alt+SU). Alternatively, to access the Connect tool, you must hold down the Alt key and then hit the S key, followed by the C key three times (Alt+SCCC). Renderer shortcuts While using any of the renderer tools, various keyboard shortcuts are available that can speed things up. They are listed below. Shortcut Tab key F11 key G key S key X, Y or Z keys A key (hold down) C key (hold down) Up/Down arrow keys Rotate mousewheel Drag with left mouse button

Action Toggles all of the property panels on or off Toggles full screen mode on or off Toggles the grid on or off Toggles the snap on or off Allows you to set the working plane Temporarily disables aligning with a "locked on" node or member Temporarily disables attaching to a node or member Zooms in/out Zooms in/out Rotates

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Drag with right mouse button

Pans

Many of the other shortcuts listed below are also available in the renderer Other shortcuts The following list shows a number of special mouse and keyboard shortcuts that operate some of the most useful and commonly used tools. Action Zoom in Zoom out Zoom full Zoom previous Pan down Pan up Pan left Pan right Pan in renderer

Rotate down Rotate up Rotate left Rotate right Rotate in renderer

Enlarge load diagram Reduce load diagram

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Keyboard shortcut Up arrow Down arrow Right arrow Left arrow Ctrl+Up arrow Ctrl+Down arrow Ctrl+Right arrow Ctrl+Left arrow

Mouse shortcut Mousewheel forwards Mousewheel backwards

Ctrl+Mousewheel forwards Ctrl+Mousewheel backwards Shift+Mousewheel forwards Shift+Mousewheel backwards Hold the right mouse button down and move the mouse

Shift+Up arrow "V"+Mousewheel forwards Shift+Down "V"+Mousewheel backwards arrow Shift+Right "H"+Mousewheel forwards arrow Shift+Left arrow "H"+Mousewheel backwards Hold the left mouse button down and move the mouse "L"+Up arrow

"L"+Mousewheel forwards

"L"+Down arrow

"L"+Mousewheel backwards

Getting Started

Enlarge deflection diagram Reduce deflection diagram

"D"+Up arrow

"D"+Mousewheel forwards

"D"+Down arrow

"D"+Mousewheel backwards

Enlarge moment diagram Reduce moment diagram

"M"+Up arrow "M"+Mousewheel forwards "M"+Down arrow

Enlarge shear force "S"+Up arrow diagram Reduce shear force "S"+Down diagram arrow Enlarge axial force "A"+Up arrow diagram Reduce axial force "A"+Down diagram arrow

"M"+Mousewheel backwards

"S"+Mousewheel forwards "S"+Mousewheel backwards

"A"+Mousewheel forwards "A"+Mousewheel backwards

Enlarge torsion diagram Reduce torsion diagram

"T"+Up arrow

"T"+Mousewheel forwards

"T"+Down arrow

"T"+Mousewheel backwards

Enlarge buckling diagram Reduce buckling diagram

"B"+Up arrow

"B"+Mousewheel forwards

"B"+Down arrow

"B"+Mousewheel backwards

Enlarge stress diagram Reduce stress diagram

"E"+Up arrow

"E"+Mousewheel forwards

"E"+Down arrow

"E"+Mousewheel backwards

Previous load case Next load case

Page up Page down

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First load case Last load case

Home End

Previous filter Next filter No filter Last filter

Ctrl+Page up Ctrl+Page down Ctrl+Home Ctrl+End

Previous saved view Shift+Page up Next saved view Shift+Page down First saved view Shift+Home Last saved view Shift+End Repeat last command

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Spacebar

Input Methods Input methods There are four main ways in which data can be input into SPACE GASS. Structure Wizard If your model resembles one of the standard structures available in the Structure Wizard then it is the easiest way to quickly generate your model in SPACE GASS. Even if it isn’t exactly what you want, you can then use the other graphical or datasheet tools to modify the generated model to your exact requirements. Datasheet Input Each component of the SPACE GASS model can be input, edited or viewed in a Datasheet. For example, there are datasheets for nodes, members, plates, section properties, member loads, masses, etc. Datasheets are an invaluable tool for viewing data or making changes, particularly using the multi-row editing tool. Graphical Input You can use Graphical Input to input or edit any parts of the structural data or load data in your model. This is a very powerful tool that has the advantages of allowing you to make large changes quickly and see your changes visually as you make them. Importing from Other Programs SPACE GASS is able to link to other programs and import the structural model in a wide variety of formats. Some of the commonly used CAD and BIM (building information management) programs that can be linked to SPACE GASS include Tekla Structures (XSteel), ProSteel, Microstation, Frameworks Plus, StruCAD, Revit Structure, Bentley Structural and AutoCAD. You can also import from SPACE GASS text files, CSV (comma separated value) files, DXF files, SDNF files, Microstran ARC files and MS-Excel files.

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If you have your own program that generates the SPACE GASS data, if it can write the data into a SPACE GASS text file, CSV file or MS-Excel file in the correct format then it can be imported into SPACE GASS. If you wish to know the format of a CSV or MS-Excel file that is suitable for importing into SPACE GASS, the best way is to generate a small model in SPACE GASS using the structure wizard or some other method and then export it into a CSV or MS-Excel file and use resulting file as a pattern. The SPACE GASS text file format is fully explained in Text file format, but you can also generate a text file from SPACE GASS and use it as a pattern. The other formats are quite complex and are simply generated by the programs that you are importing your SPACE GASS model from. For more information, refer to "Linking to other programs". Common Database Each of the above data input methods operates on the same common database, therefore you can use any combination of methods to input your data. For example, you can use the structure wizard to generate the basic frame geometry, then graphically edit the geometry and apply some loads, followed by opening up some datasheets to view the data and make further modifications to the structure or loads. When some data has been input, regardless of the amount or type, you can produce an output report on the screen or printer. In addition, regardless of which input method you use, the graphics display area displays the current state of the structural model graphically. A graphics hardcopy can also be produced at any time.

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Linking to Other Programs Linking to other programs SPACE GASS can link to many other engineering, CAD and BIM (building information management) programs using a wide variety of links and file formats. Some of the commonly used CAD and BIM programs that can be linked to SPACE GASS include Tekla Structures (XSteel), ProSteel, Microstation, Frameworks Plus, StruCAD, Revit Structure, Bentley Structural and AutoCAD. Other programs that can import and/or export CIMSteel/2 (CIS/2) or IFC Step files can also be linked to SPACE GASS. These include STAAD, Risa-3D, SAP2000 ETABS, ROBOT, SmartPlant4D Structural and others Programs that can import and/or export DXF or SDNF files can also be linked to SPACE GASS, however only the basic geometry can be included in these formats. Details of the files that SPACE GASS can import/export are as follows. SPACE GASS Text File

ZIP File

CSV File

CIMSteel/2 (CIS/2) Step File

This format is ideal for people who wish to write their own programs to generate the SPACE GASS data and then import it into SPACE GASS. The format of SPACE GASS text files is fully explained in "Text file input ". This format is still available but is essentially obsolete because the native SPACE GASS job files are actually ZIP files renamed from .ZIP to .SG. This format is also ideal for people who wish to write their own programs to generate the SPACE GASS data and then import it into SPACE GASS. It is a text file with the values separated by commas that can be written by many programs including MS-Excel. Useful for transferring models with many other CAD and building

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IFC Step File

DXF File

SDNF File

MS-Excel

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management programs such as Tekla Structures (XSteel), ProSteel, Microstation, Frameworks Plus, StruCAD, Revit Structure, Bentley Structural, AutoCAD, etc. This is a very comprehensive format that includes the structural and load data. Useful for transferring models with many other CAD and building management programs such as Tekla Structures (XSteel), ProSteel, Microstation, Frameworks Plus, StruCAD, Revit Structure, Bentley Structural, AutoCAD, etc. This is a very comprehensive format that includes the structural and load data. A drawing format text file invented for AutoCAD that many programs can import and export. It is a very good means of transferring drawings from SPACE GASS in the form of plans, elevations, cross sections and connection drawings into a CAD program. Because DXF is a drawing format, when transferring a structural model to another program, it is better to use the more comprehensive and specialized CIMSteel/2 and IFC Step file formats described above. This is a steel detailing neutral file format that has now been made obsolete by the much more advanced CIMSteel/2 and IFC Step file formats described above. It can contain the structural geometry and section property data and is still used by many programs. Microsoft Excel is a very powerful tool for generating data and can be used to


MS-Word

Microstran ARC

quickly generate a structural model for importing into SPACE GASS. SPACE GASS can also export to Microsoft Excel. The data from a SPACE GASS model can be exported to a Microsoft Word document file. A format for importing Microstran models into SPACE GASS.

In order to import from or export to a SPACE GASS text file, CSV file, SDNF file, Microstran ARC file, MS-Excel file or MS-Word file, the procedure simply involves selecting the desired format from the Import or Export options in the File menu and then choosing a file name. Linking to other programs using the very comprehensive CIMSteel/2 (CIS/2) Step, IFC Step or Revit Structure transfer options are fully explained in the following sections.

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CIMSteel/2 Step, IFC Step and Revit links Complete structural models can be imported into SPACE GASS or exported to other programs using the very comprehensive CIMSteel/2 (CIS/2) Step, IFC Step or Revit Structure transfer options. Each of these formats can contain the complete structural model, including loads and design data. They can be used to link SPACE GASS with programs such as Tekla Structures (XSteel), ProSteel, Microstation, Frameworks Plus, StruCAD, Revit Structure, Bentley Structural, AutoCAD and many others that use the CIMSteel/2 (CIS/2) Step or IFC Step formats. Revit Structure is slightly different to the other programs because in addition to communicating with SPACE GASS via the CIMSteel/2 or IFC links, it can also communicate via special import and export menu items that can be added to the Revit Structure "Tools" menu. The physical and analytical models The "physical" model includes all of the "visible" information such as the geometry of the beams, columns, braces, cables, trusses, struts, ties, walls, slabs and connections. It includes all the components that make up the model’s physical attributes. The "analytical" model includes the "visible" information too, but it also contains "hidden" information such as support conditions, member end releases, offset data, section and material properties, loads, load combinations, design data and analysis results. The other main difference with the analytical model is that, depending on the program you are importing from, the geometry may be somewhat idealised so that the centroids of members line up with the members they are connected to. For example, bracing members that connect to a beam-column connection do not often line up with the centroid of the beam-column connection in the real structure and in the "physical" model, however they may be adjusted to line up in the "analytical" model. Section name conversion files One of the major obstacles to successfully transferring data between programs is that there is no standard naming convention for section property names and hence every program uses slightly different names. To solve this problem, conversion

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Linking to Other Programs files are used to convert the section names used by SPACE GASS to the names used by other programs. Conversion files are supplied with SPACE GASS for converting section names to Tekla Structures, Prosteel, Revit Structure and others. You can also make your own section name conversion files quite easily. A conversion file is simply a text file that contains a list of the SPACE GASS section names together with the library each section comes from and the name of the section that is used by the program SPACE GASS is communicating with. An extract from a typical conversion file is as follows: SG Name, SG library, Other name W21x101, US, W 21*101 W21x111, US, W 21*111 W21x122, US, W 21*122 You can see from the above example that the SPACE GASS name and the "Other name" are often very similar and sometimes only involve adding or removing spaces or changing from "x" to "*" or vice versa. Standard section name conversion files are supplied with SPACE GASS for each of the SPACE GASS section libraries and each of the well-known programs that you may want SPACE GASS to communicate with. For example, Tekla Structures conversion files are supplied for each of the SPACE GASS section libraries. Similar sets of conversion files are also supplied for Revit Structure, Prosteel, etc. Creating custom section name conversion files You must first initiate a CIS/2 or IFC import or export from the File menu to display the following form.

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Custom section name conversion files can then be created in either of two ways. 1.

You can create a custom conversion file that is a combination of some of the standard conversion files supplied with SPACE GASS. To do this you must first select a program name in the "Convert section names for" list box and then click the "Libraries" branch of the menu tree on the left and ensure that the SPACE GASS libraries from which the sections will be taken are listed in the "Library search order" box. You can then create the custom conversion file by clicking the "Create a custom section name conversion file" button.

2.

You can create a template for a custom conversion file that contains just the SPACE GASS section names and the libraries they come from, but not the "other program" names. To do this you must click the "Libraries" branch of the menu tree on the left and then ensure that the SPACE GASS libraries from which the sections will be taken are listed in the "Library search order" box. You can then create the template conversion file by clicking the "Create a template section name conversion file" button. To convert the template conversion file into a complete custom conversion file, you should edit the template file with a text editor such as Notepad and manually enter the "other program" names at the end of each line. You could also use MS-

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Linking to Other Programs Excel, however when opening the file, you must specify that the file is comma delimited, otherwise each line will appear in just one cell.

Section name conversion files are stored in the SPACE GASS program folder (usually "c:\Program files\SPACE GASS\Exe"). Details of how to import and export using these links are explained in the following sections.

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Import links You can import a CIS/2 or IFC Step file by selecting "Import - from CIMSteel/2 Step" or "Import - from IFC Step" from the File menu. When importing from Revit Structure, you can import a CIS/2 or IFC Step file created by it or you can select the "Send Model to SPACE GASS" item from the Revit Structure "Tools > External Tools" menu as explained in "Special Revit Structure Links". Even though the internal structure of CIS/2 step files and IFC step files are quite different, the importing procedure is the same and hence the following instructions apply to both.

The name of the file being imported is displayed in the "Data Filename" field and you can select another file by clicking on the button to the right of the input field. When importing, to ensure that the section names used by the source program are converted properly to SPACE GASS names, you should do the following: 1.

If you are linking with a standard program for which a section name conversion file exists, select it in the "Convert section names for" list box. If the name of the program you are linking with does not appear in the list, it simply means that there is currently no standard conversion file for that program.

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Linking to Other Programs If so, you should select "Other". You can then create and use a custom conversion file or use one that you previously created as explained in "Creating custom section name conversion files" in the previous section. Alternatively, you can just skip the custom conversion file option and the section names will be imported or exported with no conversion.

2.

Click the "Libraries" branch of the menu tree on the left to display the section libraries form as shown below.

If you selected a program name in the "Convert section names for" list box in step 1 above, ensure that the "Use a standard section name conversion file" option is ticked. This will activate the section name conversion using the standard conversion files supplied with SPACE GASS. If you selected "Other" in the "Convert section names for" list box in step 1 above, and you have a custom conversion file that you want to use, ensure that the "Use a custom section name conversion file" option is ticked and that the name of the custom conversion file is in the "Conversion filename" field. If you wish to create a custom conversion file, follow the procedure in "Creating custom section name conversion files" in the previous section. If you wish to use a mixture of custom and standard conversion files, you can tick both the "Use a custom section name conversion file" and "Use a standard section name conversion file" options. In this case, SPACE GASS will try to convert the section name using the custom conversion file first and, if the name can’t be found there, the standard conversion files will be used.

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SPACE GASS 12 User Manual 3.

You also need to check that the appropriate SPACE GASS libraries are listed in the "Library search order" box. The "Library search order" box controls which SPACE GASS libraries will be used when the section names being imported are converted. If the name of a section being imported does not appear in one of the libraries listed in this box then it will not be converted. It is therefore important that you include enough libraries in the "Library search order" box to ensure that all the sections being imported have their names converted. You can include all libraries in the box, however this may slow down the import process slightly due to the increased number of libraries that have to be scanned. If a section name appears in more than one SPACE GASS library then the libraries higher up in the list will have priority.

You can choose which components of the model to import by expanding the "Import" branch of the menu tree on the left and then clicking "Nodes" or "Members" as shown below.

You can specify the starting node number or, if you leave it at zero, the imported nodes will be automatically numbered starting from the first available number. Nodes that are very close together can be merged into one, and the connecting members and plates adjusted to suit.

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Linking to Other Programs If you select the "Adjust lower limits of node coordinates by" checkbox, SPACE GASS will find the node with the lowest coordinates and move it to the coordinates that you specify. The rest of the model will also be moved by the same amount.

You can specify the starting member and plate numbers or, if you leave them at zero, the imported members and plates will be automatically numbered starting from the first available number. Members that have an end very close to another member can be connected together. Similarly, members that cross each other within a specified distance can be subdivided and connected at the intersection point. A number of programs that generate CIS/2 and IFC Step files incorrectly mix radians and degrees when specifying member direction angles. If you are importing one of these non-standard files and find that some members are rotated incorrectly, you can select the "Assume radians for all angular measurements" checkbox to correct the problem. For more information about the "Physical" and "Analytical" models, refer to "The physical and analytical models" in the previous section.

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Export links You can export a CIS/2 or IFC Step file by selecting "Export - to CIMSteel/2 Step" or "Export - to IFC Step" from the File menu. When exporting to Revit Structure, you can export a CIS/2 or IFC Step file or you can select the "Update Model from SPACE GASS" item from the Revit Structure "Tools > External Tools" menu as explained in "Special Revit Structure Links". Even though the internal structure of CIS/2 step files and IFC step files are quite different, the exporting procedure is the same and hence the following instructions apply to both.

The name of the file being exported to is displayed in the "Data Filename" field and you can select another file by clicking on the button to the right of the input field. When exporting, to ensure that the section names used by SPACE GASS are converted properly to the names used by the destination program, you should do the following: 1.

If you are linking with a standard program for which a section name conversion file exists, select it in the "Convert section names for" list box. If the name of the program you are linking with does not appear in the list, it

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Linking to Other Programs simply means that there is currently no standard conversion file for that program. If so, you should select "Other". You can then create and use a custom conversion file or use one that you previously created as explained in "Creating custom section name conversion files" in the previous section. Alternatively, you can just skip the custom conversion file option and the section names will be imported or exported with no conversion.

2.

Click the "Libraries" branch of the menu tree on the left to display the section libraries form as shown below.

If you selected a program name in the "Convert section names for" list box in step 1 above, ensure that the "Use a standard section name conversion file" option is ticked. This will activate the section name conversion using the standard conversion files supplied with SPACE GASS. If you selected "Other" in the "Convert section names for" list box in step 1 above, and you have a custom conversion file that you want to use, ensure that the "Use a custom section name conversion file" option is ticked and that the name of the custom conversion file is in the "Conversion filename" field. If you wish to create a custom conversion file, follow the procedure in "Creating custom section name conversion files" in the previous section. If you wish to use a mixture of custom and standard conversion files, you can tick both the "Use a custom section name conversion file" and "Use a standard section name conversion file" options. In this case, SPACE GASS will try to convert the section name using the custom conversion file first and, if the name can’t be found there, the standard conversion files will be used.

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SPACE GASS 12 User Manual You can choose which components of the model to export by clicking the "Export" branch of the menu tree on the left.

The normal procedure is to export the analytical model because, as well as the geometric information, it contains "hidden" information such as support conditions, member end releases, offset data, section and material properties, loads, load combinations, design data and analysis results. However, if you are exporting to a program that requires the physical model then you should select it. Note that when exporting from SPACE GASS, the geometric information in the physical and analytical models is the same. For more information about the "Physical" and "Analytical" models, refer to "The physical and analytical models" in the previous section.

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Special Revit Structure links Revit Structure is slightly different to the other programs because there are two ways to link it to SPACE GASS. In addition to being able to communicate with SPACE GASS via the CIMSteel/2 and IFC Step file links, Revit Structure can be configured to create SPACE GASS jobs directly and also update the Revit model from them. The advantage of using the direct Revit Structure link over the CIMSteel/2 and IFC links is that after you have transferred the model to SPACE GASS, you can import the section property and steel design changes back into Revit Structure without completely replacing the Revit Structure model. The advantage of the CIMSteel/2 and IFC Step file links is that you can start with a SPACE GASS model and transfer it into Revit Structure to create a Revit model from scratch. You can’t do this with the direct Revit Structure link. Of course, you can use a combination of methods. You could start with a SPACE GASS model, export it using CIMSteel/2 or IFC to create a new Revit Structure model, add to the model in Revit Structure and then export it back to SPACE GASS using the direct Revit Structure link. Setting up the direct link between SPACE GASS and Revit Structure You can add the special SPACE GASS items to the Revit Structure "Tools" menu by running the RevitSpaceGassLink.exe file in the SPACE GASS program folder (usually "c:\Program files\SPACE GASS\Exe"). The program will attempt to find the SPACE GASS and Revit Structure program folders and then display them in the following form.

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SPACE GASS 12 User Manual If either field doesn’t display a folder name with "(file found)" at the end, you will have to click the appropriate browse button at the right of the field to select the program folder manually. Once both folders have been identified correctly you can click the Ok button and the SPACE GASS items will be automatically added to the Revit Structure "Tools" menu. Transferring from Revit Structure To create a complete SPACE GASS model from Revit Structure, click the "Send Model to SPACE GASS" item from the Revit Structure "Tools" menu.

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Linking to Other Programs When exporting to SPACE GASS, you have full control over units, connections between beams and columns, loads, member offsets, specification of tension-only members, section names, etc. If the names of sections in your Revit Structure model are different to the names used in the SPACE GASS section libraries, you can use (or set up your own) section name conversion file that converts the Revit Structure names to the SPACE GASS names. For more information, refer to "Creating custom section name conversion files" in "CIMSteel/2 Step, IFC Step and Revit links". Transferring to Revit Structure When the SPACE GASS analysis and/or design is complete, you can update the Revit Structure model by clicking the "Update Model from SPACE GASS" item from the Revit Structure "Tools" menu.

When importing from SPACE GASS you can elect to incorporate steel design data into the Revit Structure model. This is then retained in Revit Structure and returned to SPACE GASS the next time you export a model to SPACE GASS from Revit Structure.

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DXF links The DXF file format is a text format invented for AutoCAD that many programs can import and export. Because DXF is essentially a drawing format rather than for engineering models, it is limited to the basic structural geometry when used to transfer a structural model. For this reason, transferring a structural model is best done using the CIMSteel/2 (CIS/2) Step or IFC Step file formats or the Revit links which are very comprehensive and can include loads. The DXF format is, however, a very good means of creating drawings in the form of plans, elevations, cross sections and connection drawings for transferring into a CAD program. Details of how to import and export DXF files are explained in the following sections.

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Importing DXF files You can import a DXF file by selecting "Import - from DXF" from the File menu. When importing, SPACE GASS interprets each discrete line in a CAD drawing as a member. This has two ramifications that you will need to consider. 1. CAD programs do not know that intersecting lines need to be segmented into sub-members with nodes at the intersection points. For example, if you drew the top and bottom chords of a truss with just two lines adding the struts and braces as separate lines, SPACE GASS would consider that the chords are not connected to the web members except at the chord ends. You must ensure every member that you want in the SPACE GASS model is drawn as a separate line in the CAD program. If you draw a line in the CAD program which continues past a node then the member will not be connected to that node in the SPACE GASS model. 2. You shouldn’t read a DXF file, created with full member geometry, back into SPACE GASS (it interprets each member flange and web line as an individual member).

Note that SPACE GASS only interprets LINE, 3DLINE and POLYLINE entities as geometry when importing a DXF file. All other entity types are ignored. It is usually much quicker and more efficient to draw the structure directly in SPACE GASS rather than drawing it in your CAD program and importing it into SPACE GASS. This is because SPACE GASS knows it is dealing with a structure and not just lines in a drawing.

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Exporting DXF files There are two types of DXF files that can be exported from SPACE GASS. 1.

Elevations, plans, cross sections and member schedules.

2.

Steel connection drawings.

Exporting elevations, plans, cross sections and member schedules You can export elevations, plans, cross sections and member schedules by selecting "Export – to DXF" from the File menu.

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Linking to Other Programs Full geometry You can elect to simply export a wireframe drawing that consists of lines along the centrelines of each member, or you can also include the full member geometry which shows the actual member shapes including flanges and webs, etc. Drawings that include the full member geometry can have the geometry lines shortened by a distance factor that you specify in the General Configuration form at each end of the member so that intersecting members do not run into one another. Member schedule Selecting this check box causes a member schedule to be included in the drawing. Z axis vertical AutoCAD and some other 3D CAD programs assume that the Y-axis is vertical for 2D drawings, while the Z-axis is vertical for 3D drawings. If this check box is selected then the global Z-axis is made vertical in the drawing, otherwise the Y-axis is vertical. Label members Members can be unlabelled, or labelled with the member names, member marks or both. Draw with By choosing 3DLINEs or FACES you can generate a full 3D drawing, or by choosing 2DLINEs you can limit the drawing to just 2D views, elevations, plans or cross sections of the structure. Note that FACEs support hidden line removal and shading while 3DLINEs do not. A 3D drawing complete with full member geometry is very useful for visualizing how the structure fits together and for checking whether members clash with each other or not. Similar 3D drawings with hidden line removal can also be viewed directly in SPACE GASS without having to go to a CAD program (see also View rendered model). Because almost all structural drawings are made up predominantly of 2D plans, elevations and details, the ability of SPACE GASS to produce 2D drawings of the frame is one of the most useful aspects of being able

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SPACE GASS 12 User Manual to export DXF files. SPACE GASS allows you to create a series of 2D vertical or horizontal "slices" at any position through a 3D frame and have them exported to CAD as cross sections, elevations or plans. These 2D drawings can contain the full member geometry complete with dashed and dotted hidden lines. It is then a simple matter for a draftsperson to use a CAD package, such as AutoCAD, to add connections, notation, etc. and complete the structural drawing. 2D drawing plane If you have specified a 2D drawing by choosing 2DLINEs in the "Draw with" combo box, you must choose a 2D drawing plane here. 2D drawing limits If you have specified a 2D drawing, then you must nominate upper and lower drawing plane limits. The limits will be along the global axis at right angles to the 2D drawing plane. Any members that lie between the two limits will be included in the drawing. Scale You can scale the drawing up or down with this field. For example, a scale of 10 causes the drawing dimensions to be reduced by a factor of 10. Units for the DXF drawing file are the same as those used in SPACE GASS. Title Typing a title into this field causes it to appear at the bottom of the drawing. DXF layer names Layer names can be any names of up to 8 characters. AutoSKETCH requires layer names to be integers from 1 to 10 in all cases. It is recommended that you configure your CAD software so that the hidden line layer uses dashed or dotted lines. This ensures that they can be easily distinguished from visible geometry lines. You can specify that the layers should be section-specific for centerlines, full geometry and/or text. This means that each member type will have its own layer rather than the entire frame just going into a single layer. You can then set your CAD software so that each layer has a different color, making identification of the various section types very easy.

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Linking to Other Programs Exporting steel connection drawings During or after a steel connection design, you can create fully detailed and annotated drawings of the connections and export them to DXF drawing files in either of two ways. 1.

Enable the "Generate drawings for a CAD system" option at the beginning of the connection design phase (see also Running a steel connection design). This causes a DXF drawing file to be created for every connection designed.

2.

Click the toolbar button after the connection design phase to view the connection drawings graphically and then selectively produce DXF files from there (see also View steel connection drawings).

Using either method, the final result is the same. You can control the drawing layer names by setting them in the SPACE GASS configuration data. An example of a steel connection drawing produced automatically by SPACE GASS is shown as follows.

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SPACE GASS connection detail

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Modelling the Structure Modelling the structure Before a frame can be modelled and analysed with a program such as SPACE GASS, it must first be idealised and modelled mathematically. The most popular mathematical model uses the concept of nodes connected by elements of a finite size (finite elements). SPACE GASS requires that frames are represented by nodes connected by members, cables or plates. Such nodes are generally free to move and rotate in space. Practical structures, however, are connected to a footing in some way, and so node restraints must be applied which limit the movement of selected nodes. The relative movement between nodes connected by a member, cable or plate is a function of the section and material properties of that element. Loads can be mathematically represented in the model and can be applied elements. Such loads include all of the normal force and moment type loads, in addition to load inducers such as prescribed displacements and temperature differentials. A single analysis can consider numerous load cases, each of which may contain many different load types. During the analysis phase, all unrestrained node displacements (degrees of freedom) are calculated for each load case. Element forces and moments are then determined from the relative movement of the nodes they are connected to and, finally, reactions are calculated by equating element reactions at each restrained node. If the analysis selected is non-linear, SPACE GASS does an initial linear analysis and then modifies the stiffness matrix for each member based on the previous analysis node displacements and member axial forces. It then re-analyses the structure for the modified member stiffness and continues iterating the analysis phase in this way until convergence is achieved. Note that because the plate elements are linear elements at this stage, their stiffness is not modified during the non-linear analysis iterations.

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Coordinate systems The geometry of a structural model is referenced by a set of global XYZ axes. Each member and plate element also has its own set of local xyz axes so that items such as section properties and local loads can be more easily referenced. All axes are right hand orthogonal. This means that if you are looking at the XY plane with the Y-axis pointing upwards and the X-axis pointing to the right, the Zaxis points towards you as shown below. Global Axes The shape and position of a structure in space is defined by a set of global axes (X,Y,Z). All node coordinates, for example, are input relative to the global axes system. The global XZ plane is assumed to be horizontal, while the global Y-axis points vertically upwards. Note that although SPACE GASS assumes that the Y-axis is vertical by default, it can be configured to set the Z-axis to vertical. This is done via the Viewpoint tool.

Global Axes

Member Axes The local axes for a member have their origin at node A and are defined as follows: 1. The x-axis lies along the axis of the member and points from node A to node B. 2. The local y-axis is normal to the local x-axis and points in the same general direction as the global Y-axis. It is orientated such that the local xy-plane is parallel to the global Y-axis.

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Modelling the Structure 3. The local z-axis is orthogonal with x and y. For members that have their longitudinal axis parallel to the global Y-axis, rule 2 is undefined and hence, for these members, the local z-axis points in the same direction as the global Z-axis. 4. If a direction angle, node or axis is defined then the member is rolled about it’s longitudinal x-axis by the direction angle or, if a direction node or axis is defined, by an amount such that the local y-axis is aligned with the direction node or axis as shown below.

Member Local Axes

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SPACE GASS 12 User Manual Member Direction Angle

Member Direction Node

Member Direction Axis

If you are unsure of the orientation of the local axes for a particular member, you can display them graphically (see also View local axes).

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Modelling the Structure Plate Axes The local axes for a plate have their origin at the centre of the plate and are defined as follows: 1. The x-axis is in the plane of the plate and is parallel to the line joining node A and node B. 2. The local y-axis is also in the plane of the plate and is normal to the local x-axis. 3. The local z-axis is normal to the plane of the plate and is orthogonal with x and y. 4. If a direction angle, node or axis is defined then the local axes are rotated about the plate’s normal z-axis by the direction angle or, if a direction node or axis is defined, by an amount such that the local y-axis is aligned with the direction node or axis as shown below. Note that defining a direction angle, node or axis affects the orientation of the plate’s axes but not the orientation of the plate itself.

Plate Local Axes

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Plate Direction Angle

Plate Direction Node

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Plate Direction Axis

If you are unsure of the orientation of the local axes for a particular plate, you can display them graphically (see also View local axes).

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Sign conventions Items which act along or about an axis are considered to be positive when they act along or about the positive axis direction. Positive rotations conform to the right hand screw rule shown as follows.

Right Hand Screw Rule

Applied loads have their sign determined by the axes system in which they are referred. Most types of member and plate loads can be specified in either the global or local system, however node loads and self weight are always referenced by the global system. Node displacements are positive if they displace along or around the positive global axis directions. External reactions are positive if they act along or around the positive global axis directions. Member Actions Member actions follow the sign conventions as follows.

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Member Forces and Moments

Positive axial forces cause compression in the member. Positive moments cause compression on the positive axis side of the member.

Channel and angle sections have their flange toes pointing in the direction of the local z-axis. Positive y-axis moments therefore cause the flange toes to go into compression. Positive shears cause the node A end of the member to translate in the direction of the positive axis with respect to the node B end. Positive torsions cause the node A end of the member to rotate anti-clockwise with respect to the node B end when observed from the node B end. Plate Actions Plate actions follow the sign conventions as follows.

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Plate Forces

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Modelling the Structure Plate Moments

When calculating the design moments for reinforced concrete slabs, the twisting moment Mxy must be combined with the normal bending moments Mx and My. The Wood-Armer method is commonly used for this and is explained in "Bending Moments in Reinforced Concrete Slabs" below.

Plate Stresses

Note that plate elements have no rotational stiffness about their local z-axis. This means that there is effectively a rotational pin connection between the plate and its corner nodes about the axis normal to the plate. Positive moments cause compression in the top (positive z-axis) face of the plate. Plane Stress Three dimensional objects subjected to loads generally have three principal stresses, however in structural elements where one dimension is very small

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SPACE GASS 12 User Manual compared to the other two (ie. plate elements), one of the three principal stresses is zero and a state of "plane stress" is said to exist. In this case, the stresses are negligible with respect to the smaller dimension as they are not able to develop within the material and are small compared to the in-plane stresses. Principal Stress For plates subjected to plane stress, there are two principal stresses acting in the principal axis directions. The angle between the principal axes and the local x and y axes is called the principal angle. The principal stresses can be calculated from x, y and xy using Mohr circle theory as follows. 1 (max) = (x + y)/2 + SQRT((x - y)2/4 + xy2)  (min) = (x + y)/2 - SQRT((x - y)2/4 + xy2) xymax = ( - )/2  = Tan-1(2xy/(x - y))/2 where x, y and xy are the membrane and shear stresses in the local axis directions (as per the above diagrams), 1 and 2 are the principal stresses, xymax is the maximum shear stress and  is the principal angle. von Mises Stress Richard von Mises (an eminent Austrian scientist who worked on solid mechanics, fluid mechanics, aerodynamics, aeronautics, statistics and probability theory) found that, even though none of the principal stresses exceeds the yield stress of the material, it is possible for yielding to result from the combination of stresses. The von Mises criteria is a formula for combining these principal stresses into an equivalent stress, which is then compared to the yield stress of the material. The yield stress is a known property of the material and is usually considered to be the failure stress. The equivalent stress is often called the "von Mises Stress" as a shorthand description. It is not really a stress, but a number that is used as an index. If the von Mises stress exceeds the yield stress, then the material is considered to be at the failure condition. The von Mises stress can be calculated from the principal stresses according to: vm = SQRT(((1 – 2)2 + 12 + 22)/2) where 1 and 2 are the principal stresses and vm is the equivalent or "von Mises" stress.

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Bending Moments in Reinforced Concrete Slabs When evaluating the design moments for a reinforced concrete slab, the twisting moment Mxy must be taken into account in addition to the normal bending moments Mx and My. Mxy contributes a moment effect to both the principal bending directions x and y. Using the Wood-Armer method, the design moments Mx* and My* can be determined as follows: To design bottom reinforcement (ie. calculate moments that cause tension in the bottom face): Mx* = Mx + | Mxy | My* = My + | Mxy | If either of Mx* or My* from the above calculations are < 0 then If Mx* < 0 then Mx* = 0 and My* = My + | Mxy2/Mx | If My* < 0 then My* = 0 and Mx* = Mx + | Mxy2/My | To design top reinforcement (ie. calculate moments that cause tension in the top face): Mx* = Mx - | Mxy | My* = My - | Mxy | If either of Mx* or My* from the above calculations are > 0 then If Mx* > 0 then Mx* = 0 and My* = My - | Mxy2/Mx | If My* > 0 then My* = 0 and Mx* = Mx - | Mxy2/My | Further information can be found by searching for "Wood-Armer" on the Internet or at web sites such as http://www.scribd.com/doc/76706580/Slab-Design-byWood-Armer-Method or http://www.scribd.com/doc/51463621/Wood-Armer

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Ill-conditioning and instabilities The most common analysis errors are caused by structures that are not correctly conditioned or stabilised. Ill-conditioning commonly occurs when frames contain members of widely varying stiffness’s. When a very stiff member is connected to a very flexible member and their stiffness matrices are assembled into the structure stiffness matrix, some of the stiffness terms of the flexible member can be completely lost due to their insignificance in comparison with the stiffness terms of the stiff member. Hence, the flexible member is not completely represented and illconditioning occurs. SPACE GASS contains an algorithm which checks for possible ill-conditioning and displays warning messages if appropriate. Generally, these messages appear well before ill-conditioning actually occurs. They do, however serve to highlight structures which are close to being ill-conditioned. If after the analysis, the sum of the reactions equals the sum of the applied loads then it can be assumed that the frame is well conditioned. Instabilities occur when one or more nodes are free to translate or rotate without resistance from the frame. Sometimes unstable structures are very easy to detect, such as when restraints have not been applied or when an obvious collapse mechanism is possible. Instabilities are often very subtle and difficult to isolate. For example, if an unrestrained node has a pinned connection to each of its connecting members then it would be free to rotate and an instability would result. This type of instability can be hard to detect because it only affects one node in the structure. True trusses must therefore have every rotational degree of freedom restrained. Sometimes highly ill-conditioned frames can also be interpreted as being unstable by the program. Another common type of instability occurs when a group of members connected end-to-end in a straight line are free to rotate about their longitudinal axis. The instability occurs because during the analysis the program is unable to determine the amount of rotation of the intermediate nodes.

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Modelling the Structure Some instabilities cannot be detected by a static analysis, and you should therefore be wary of results that contain very large deflections or deflections that occur in the wrong direction. However most instabilities can be detected by a buckling analysis and are identified by very low buckling load factors. If you get buckling load factors that are below the minimum allowable value (eg. shown as "<0.001" when the minimum allowable value is 0.001), this could indicate an instability problem rather than a buckling problem. It is even more likely to be an instability problem if the low buckling load factors occur in every load case. If the model contains instabilities, the buckling analysis may, in some cases, give invalid results. In the absence of instability or buckling messages from the static analysis, you should always check the deflections to see if they are excessive or not. Excessive deflections are sometimes the only indicator of instabilities. There are no hard and fast rules to follow in the detection of conditioning and stability problems, however if the structure is clearly drawn and examined, the problem usually becomes evident to any moderately experienced user. SPACE GASS is now able to automatically rectify some instabilities caused by nodes that are free to rotate or translate in one or more directions without resistance from interconnecting members, restraints or constraints. For more information, refer to "Stabilize unrestrained nodes" in Running a static analysis.

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Project Data Project data This chapter describes in detail each type of data that can be included in the analysis model.

This chapter does not include design data (see also "Steel member design", "Steel connection design" and "Concrete column design"). See also Input methods. See also Output. See also Print graphics.

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Units

SPACE GASS can handle a variety of different unit sets. The units do not need to be consistent or even belong to the same system (ie. you can mix units from Metric and Imperial). You can quickly select standard Imperial or Metric by clicking the "Imperial" or "Metric" buttons and then make further individual changes as required. If the "Convert the current job for any unit changes" box is checked then all of the data in the current job will be converted in accordance with the units changes you made. If the box is not checked then the units will change but none of the job data will be converted. If the "Save the above units as the default for new jobs" box is checked then SPACE GASS will use the selected units as the default every time you start a new job in the future.

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Project Data

If you are entering data and are not sure what the correct units are for that particular type of data, you should either (a) select the datasheet (from the datasheets button on the top toolbar) for the particular type of data you are entering and observe the units displayed at the bottom-right of the datasheet or, (b) produce an output report and observe the units displayed next to each section heading. ! IMPORTANT NOTE ! Before accepting any output from SPACE GASS, please check that all of the input and output data conforms to the units you have selected. You can do this most conveniently by producing a full output report and observing the units that are shown next to the heading in each section of the report. ! IMPORTANT NOTE ! If you change units for any or all data types after having input some data and you want the data to be converted, then you must ensure that the option to "Convert the current job for any unit changes" is checked. Otherwise the data will not be converted automatically. See also The structure menu. See also Initiator.

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Job details and attachments This tool allows you to specify headings for your job and attach other files that you want to embed and save with the job. Headings

Project heading Allows you to describe the project. Job heading Allows you to describe the job. Designer Identifies you as the designer. Notes Allows you to describe the job in more detail.

Attachments You can attach external documents, drawings, spreadsheets and other files to your job that are then saved and embedded into the main .SG job file. They can be added, opened or extracted using the form shown below.

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Project Data

See also The structure menu. See also Headings text.

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Node data

Nodes are used to define the geometry of the structure in 3D space, and to mark the start and end points of members in the model. There are six possible displacements (degrees of freedom) per node in a 3D frame. They are translation along, and rotation about, X,Y, Z. Node The node numbering order is of no consequence and successive node numbers do not have to be sequential. For example, a straight beam with five nodes could just as easily be numbered 24,8,2,13,99 as 1,2,3,4,5. It is possible to leave gaps in the numbering sequence to allow for nodes which might be inserted later.

While the node numbering sequence doesn’t effect the results it is easier to interpret the results of an analysis if a logical numbering sequence has been used.

You can renumber nodes at any stage by using the graphics renumbering facility (see also Renumber). X, Y and Z coordinates Global coordinates of the node that may be positive or negative. Dummy nodes These are nodes that are not connected to any members. They are useful as direction nodes or reference points. See also Node restraints. See also Master-slave constraints.

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Project Data See also Members. See also Nodes text. See also Datasheet Input. See also Node properties. See also Draw.

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Member data

Members represent the actual beams, columns, ties, struts, cables, braces, etc. in the real structure. They must be prismatic and must be connected to a node at each end. Member The member numbering order affects the analysis frontwidth, however this is of no consequence if the wavefront optimiser is used. The graphical renumbering tool also means that the initial member numbering order is unimportant because it can be easily changed at any time. Successive member numbers do not have to be sequential. Type Choices are:

Normal, Tension-only, Compression-only, Cable.

While in tension, tension-only members act identically to normal members with axial, flexural, torsional and shear capacity. However, if they go into compression then they are automatically disabled and act as if they have been removed from the model. Members such as tension bracing and slender ties fall into this category.

Slender members that rely on axial tension to resist lateral loads applied to them should be modelled as cables rather than as tension-only members! While in compression, compression-only members act identically to normal members with axial, flexural, torsional and shear capacity. However, if they go into tension then they are automatically disabled and act as if they have been removed

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Project Data from the model. This type of member is useful in situations such as where a support member resists download loads by bearing on a footing but is unable to resist any uplift. In both tension-only and compression-only cases, the program does an initial analysis and then scans for tension-only members that have gone into compression, and compression-only members that have gone into tension. If any of these are found they are disabled and the structure is re-analysed. This process continues until all tension-only members are in tension and all compression-only members are in compression. Note that disabled members are sometimes re-enabled if their axial force reverses sign during the iteration process.

During a dynamic analysis, tension-only and compression-only members are treated as normal members that can take tension and compression. See also Tension-only and compression-only effects. Cable members use axial tension only to resist lateral loads. They have no flexural, torsional or shear capacity, and so to avoid instabilities you must restrain all rotational degrees of freedom for nodes connected to cable members which are not rotationally fixed to other members. Cable end fixities of FFFFFF, FFFFFR, FFFFRR, FFFRRR all give the same results. Cables that aren’t laterally loaded are treated as tension-only members which become disabled if they go into compression. Laterally loaded cables sag instead of taking compression.

Cable members cannot be included in a dynamic analysis. See also Cable members. Cable length If the member type is "Cable" then an unstrained cable length can be specified to allow for cable sag when the cable length is different to the chord length (as follows). A zero cable length indicates that the unstrained cable length is equal to the chord length.

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SPACE GASS 12 User Manual Chord length The chord length is the straight line distance between the member ends Note that a member’s chord length may not be equal to the distance between it’s end nodes if offsets exist for that member. Using a direction angle, node or axis If a direction angle, node or axis is defined then the member is rolled about it’s longitudinal x-axis by the direction angle or, if a direction node or axis is defined, by an amount such that the local y-axis is aligned with the direction node or axis as shown below. Note that the three member orientation members are mutually exclusive. Hence, setting one of them to a desired value causes the other two to be disabled.

Member Local Axes

Direction angle The direction angle (degrees), also called the skew angle, allows you to roll the member (with its local axes) about it’s longitudinal axis. It is normally set to zero so that the member local y-axis lies in a vertical plane.

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Project Data

Member Direction Angle

Direction node Selecting a direction node aligns the local xy-plane with the nominated node. A direction node can be a normal node or a dummy node (one which is not connected to any members).

Direction Node

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Direction axis Choices are: X axis, Y axis, Z axis, -X axis, -Y axis, -Z axis, N/A. Selecting a direction axis aligns the local xy-plane with the nominated axis (eg. -Z axis selected in the diagram as follows).

Direction Axis

If you are unsure of the orientation of the local axes for a particular plate, you can display them graphically (see also View local axes). Node A and B The two end nodes connected to each member are referred to as node A and node B. Node A is considered to be at the start of the member and any external loads applied to the member are located by their distance from node A. Node A cannot be equal to node B, however there are no restrictions relating to node A being numerically bigger than node B or vice-versa. End fixity A member may be released or fixed to its end nodes with varying degrees of fixity. Member end fixity is referenced by the local axes system and there are six possible components at each end which may be fixed or released. These components are

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Project Data specified by a six character code corresponding to translational fixity along x, y and z and rotational fixity about x, y and z respectively. The letter "F" represents fixed and "R" represents released. Thus, as an example, a pin ended truss member with no rotational end fixity in a 3D frame could be modelled using a fixity of "FFFFRR" at each end (or FFFRRR if the torsions are also released), while a pin ended truss member in a 2D frame could have fixities of "FFFFFR". Members with fully fixed ends would have fixities of "FFFFFF". You can also specify a spring stiffness, allowing you to model a semi-rigid joint. The letter "S" represents a spring stiffness, applicable to rotation about the local y or z axes of the member. If you specify a spring stiffness in the fixity code you will also need to enter a corresponding stiffness in the y/z stiffness fields. ! IMPORTANT NOTE ! Member end fixities should not be confused with node restraints. Member end fixities specify how members are connected to their end nodes, while node restraints specify how nodes are connected to the footings or other supports. Note that completely rigid frame members should have member end fixities of "FFFFFF" regardless of whether the frame has pin based supports or not. Section The section property number references a particular member cross section from the section property data. Thus, members with identical section properties would have the same section property numbers. The current section property for the members selected is displayed in this field. If no section property has been chosen, or if more than one section property applies to the selection, this field will be blank. The source is displayed along with an indication of whether the section has been flipped and what type of angle section was chosen (if appropriate). You can change the section property by entering another section property number. If this number corresponds with a section which has already been defined, the corresponding properties will be displayed. All of the members selected will have this property applied to them. Material The material property number references a particular material from the material property data. Thus, members with identical materials would have the same material property numbers.

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For full details of the forces and moments in members, refer to "Sign conventions". See also Section properties. See also Material properties. See also Member offsets. See also Members text. See also Datasheet Input. See also Member properties. See also Draw.

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Project Data

Plate data

A mesh of plate elements can be used to represent walls, slabs, plates, etc. in the real structure. Plate elements can be triangular or quadrilateral with a node at each vertex. They can be connected at their nodes to other non-plate elements such as beams, columns, cables, etc. Plate The plate numbering order affects the analysis frontwidth, however this is of no consequence if the wavefront optimiser is used. The graphical renumbering tool also means that the initial plate numbering order is unimportant because it can be easily changed at any time. Successive plate numbers do not have to be sequential. Type Each plate can be specified as thick (using Mindlin plate theory – Ref. 19,20,21) or thin (using Kirchoff plate theory – Ref. 22,23). Transverse shear is not considered for Kirchoff plate theory and for the vast majority of applications in structural engineering we would recommend that Mindlin plate theory be used. Direction angle, node, axis By default, a plate’s local axes are such that x and y are in the plane of the plate and z is normal to the plate. The x-axis is aligned with a line joining nodes A and B and the y-axis is orthogonal with respect to x and z. The direction fields allow you to rotate the x and y axes about the plate’s normal z axis. The purpose for this is to control the axes for which the output results apply.

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Plate Axes

It is recommended that for the plate elements in a surface, you align all their inplane axes in the same direction rather than having them orientated randomly. For circular plates, you may elect to have all of the axes aligned in the same direction or, alternatively, you could align them radially or tangentially depending on which type of output you require. If the plate axes are orientated randomly then the results will be for different axis directions and they will be difficult to compare. It will also be difficult to produce meaningful contour diagrams if the plate axes are not aligned. The Align plate axes tool can be used to quickly align the axes for a selection of plate elements. It will also optionally reverse the normal z-axis of some plate elements if they are not all pointing in the same direction. You can also use the Reverse plate direction tool as an alternative way of reversing the normal z-axis.

Direction Angle

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Project Data

Direction Node

Direction Axis

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SPACE GASS 12 User Manual If you are unsure of the orientation of the local axes for a particular plate, you can display them graphically (see also View local axes). Actual thickness This is the actual thickness of the plate and is used to calculate it’s self weight and self-mass if they have been specified. The thickness should be limited to around 15% of the in-plane plate dimensions for Mindlin plates and around 5% for Kirchoff plates. The plate dimensions relate to the overall plate size and not the element size. Membrane thickness This is used to calculate the membrane stiffness of the plate and is usually the same as the actual thickness. The membrane stiffness terms are the ones that affect Fx, Fy and Fxy as shown below.

Bending thickness This is used to calculate the bending stiffness of the plate and is usually the same as the actual thickness. The moment of inertia per unit length of the plate is taken as Tb3/12, where Tb is the bending thickness. The bending stiffness terms are the ones that affect Mx, My and Mxy as shown below.

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Project Data

When calculating the design moments for reinforced concrete slabs, the twisting moment Mxy must be combined with the normal bending moments Mx and My. The Wood-Armer method is commonly used for this and is explained in "Sign conventions". Shear thickness This is used to calculate the transverse shear stiffness of the plate and is only used for Mindlin (thick) plate theory. For a uniform plate the shear thickness should be approximately Ta*(5/6) to be consistent with Mindlin thick plate theory, where Ta is the actual plate thickness. The transverse shear stiffness terms are the ones that affect Vxz and Vyz as shown below.

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Offset Plates can be offset along their normal z-axis. This may be required to line them up with other interconnecting elements such as other plates or members.

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Project Data Material Material property number references a particular material from the material property data. Thus, plates with identical materials would have the same material property numbers.

For an accurate analysis, plates must be properly meshed into elements that are a suitable size, shape and pattern. For more information, refer to the Mesh tool.

For full details of the forces, moments and stresses in plates, refer to "Sign conventions".

See also Material properties. See also Plates text. See also Datasheet Input. See also Plate properties. See also Draw.

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Node restraint data

Node restraints are used to model the structure’s supports. They are sometimes referred to as boundary conditions. Unrestrained nodes are generally free to move along or about any axis direction, however practical structures must be restrained to a footing in some way, otherwise instabilities would occur. Nodes can be restrained about one or all of their six degrees of freedom and such a restraint may take the form of a fixed restraint or a flexible restraint. If a degree of freedom is given a flexible restraint then a spring stiffness must also be input. Fixing a degree of freedom has the effect of immobilizing that node movement, while specifying a flexible restraint causes the node movement to be a function of the spring stiffness. Node restraints are specified by a six character code corresponding to restraints along X, Y and Z and about X, Y and Z respectively. "F" represents fixed, "R" represents released and "S" represents spring (or flexible). "D" restraints are no longer supported and "F" should be used instead. For example, a pin-based support that prevents all translations but allows the node to rotate about X, Y or Z would have a restraint code of FFFRRR. Alternatively, a roller support that allows the node to move in the X direction only and rotate about X, Y or Z would have a restraint code of RFFRRR. A fully built-in (encastre) support would have a restraint code of FFFFFF. A restraint that prevents movement in the Z direction while allowing all other movements and rotations would have a restraint code of RRFRRR. ! IMPORTANT NOTE !

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Project Data Member end fixities should not be confused with node restraints. Member end fixities specify how members are connected to their end nodes, while node restraints specify how nodes are connected to the footings or other supports. Note that completely rigid frame members should have member end fixities of "FFFFFF" regardless of whether the frame has pin based supports or not. General restraint The general restraint facility allows you to apply a restraint to all otherwise unrestrained nodes. For example, if you have a frame with two pin based supports and you want to prevent all translations in the Z direction for all of its other nodes, you could apply restraints of FFFRRR to the two support nodes and specify a general restraint of RRFRRR. In order to input a general restraint, you simply apply the desired restraint to any unrestrained node and then tick the "General" box (or select "Yes" in the General Restraint column if you are using a datasheet). Using a general restraint saves data entry time and reduces the quantity of printed output. Note that output reports only show the general restraint code on one node, even though the analysis has assumed that it applies to all unrestrained nodes. ! IMPORTANT NOTE ! The general restraint facility should be used with great care and only if you are absolutely sure of the effect it has on your model! If you apply a general restraint early in the development of your model and then forget that it exists at some later stage when it is no longer appropriate, you could be over-restraining your model. This could happen if nodes are added that shouldn’t get the general restraint. It could also happen if you initially use a general restraint to prevent all out-ofplane movements in a 2D frame for example and then extend the frame to 3D and forget to remove the general restraint. X, Y and Z axial stiffnesses Axial spring stiffness for degrees of freedom restrained with "S". Axial spring stiffnesses must always be greater than zero. When modelling the elastic properties of soil as a spring support, the spring stiffness is based on the modulus of subgrade reaction of the soil. This is a notoriously difficult parameter to get an accurate figure for. The following typical values of the modulus of subgrade reaction (to be used as a guide) are extracted

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SPACE GASS 12 User Manual from J. E. Bowles, "Foundation analysis and design", McGraw Hill 4th Edition, 1988. Soil Type Loose sand: Medium dense sand: Dense sand: Clayey medium dense sand: Silty medium dense sand: Clayey soil with qu < 200 kPa: Clayey soil with qu in range 200 to 400 kPa: Clayey soil with qu > 800 kPa:

Modulus of Subgrade Reaction

4800 - 16000 kN/m3 9600 – 80000 kN/m3 64000 – 128000 kN/m3 32000 – 80000 kN/m3 24000 – 48000 kN/m3 12000 – 24000 kN/m3 24000 – 48000 kN/m3 > 48000 kN/m3

The spring stiffness to be input into SPACE GASS is simply equal to the modulus of subgrade reaction multiplied by the area of the footing that the spring is modelling. For example, if you have a 600mm wide strip footing supported on soil with a modulus of subgrade reaction of 80000 kN/m3 and the soil is modelled as springs spaced 500mm apart, the axial stiffness of each spring would be 80000 x 0.600 x 0.500 = 24000 kN/m. Units for the spring stiffness are shown in the headings of the node restraints datasheet. X, Y and Z rotational stiffnesses Rotational spring stiffness spring stiffnesses for degrees of freedom restrained with "S". Rotational spring stiffnesses must always be greater than zero. Important note about restraining 2D frames It is common practice amongst some engineers to restrain all out-of-plane movements in 2D frames. While this is generally appropriate for static analyses (provided there are no out-of-plane loads), it may not be appropriate for buckling and dynamic frequency analyses. This is because the frame may buckle or vibrate in an out-of-plane direction even though there are no loads in that direction. Of course, nodes that are braced in the out-of-plane direction should be restrained in that direction, however nodes that can move out-of-plane in the real structure should not be restrained in that direction in the model. Failure to do this could affect the buckling load factors, effective lengths and dynamic natural frequencies and mode shapes, and could result in unsafe designs. For example, if a 2D frame rafter is sub-divided, the intermediate nodes should not be restrained in the out-of-plane direction unless they are braced in that direction in

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Project Data the real structure. Restraining them would prevent any out-of-plane buckling or vibration modes that could occur if the rafter member hadn’t been sub-divided. Another example is a pin support for a 2D XY-plane frame column base which could be modelled with the standard 2D pin base restraint code of FFFFFR, however this would prevent rotations about the global X-axis. In reality, a column pin support would probably allow rotations about both horizontal axes and hence a restraint code of FFFRFR would be more appropriate. Restraining the rotation about the X-axis would affect the out-of-plane buckling and vibration modes of the column and could result in incorrect results. The general rule to follow is that if a node is free to move or rotate in the real structure then it should not be restrained in that direction in the model. Be careful with the general restraint, as it is applied to all nodes that don’t have their own restraint, and for some nodes this may not be appropriate.

If you have applied a general restraint and require some nodes to not have a restraint at all, you can prevent them from getting the general restraint by restraining them with a code of RRRRRR. See also Node restraints text. See also Datasheet Input. See also Node properties. See also View node / member / plate properties.

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Section property data You can display the section property data for a member by clicking the in the Member Properties form.

button

Section properties must be input for each type of member cross section in the model. Each section property describes the geometric properties of a single cross section relative to the local member axes. Section There are two fields, one for the section property number and the other for the section name. Section property numbers do not have to be sequential or in any particular order. The section property name is used as a description for the section, and as a reference for sections which have been read from a library. Source This indicates the source of the section. There are four different sources: Manual: Library: Shp Bldr: Std Shps:

User defined properties. A shape taken from a library. The source will be the library name (eg. AUST300). Section defined in the Shape Builder. Section defined in Standard Shapes.

See also Standard sections libraries. See also Shape builder.

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Project Data

If you create a section in the shape builder by importing it from the library, and you don’t make any changes to it, the source will be the name of the library the section was taken from. However, you can still edit the shape via the shape builder. You can also edit other library sections in the shape builder, even if the section wasn’t input via the shape builder. Flipped "YES" if the section has been flipped (see also Flipping a section). Angle Type Indicates the angle configuration. Choices are:

Single, Short-Short, Long-Long, Starred.

See also Angle sections. Area of section Cross sectional area of the section. Torsion constant Torsional stiffness of the cross section. Calculating the torsion constant for arbitrary cross sections can be quite complex, particularly if the cross section changes shape (warps) under torsion. For example, a circular tube has a relatively high torsion constant because it doesn’t warp under torsion. However, if a saw cut is made through the tube wall the torsion constant is drastically reduced because the cross section can change shape under very small torsion loads. Thus two shapes with very similar geometric properties can have substantially different torsion constants.

The torsion constant for shapes which cannot warp is equal to the polar moment of inertia. The torsion constants for various common shapes can be calculated using the following formulae.

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Solid circle:

Circular tube: Solid square:

Solid rectangle: where A & B are length and breadth (or vice-versa) and A>B I, H, T, L and angle J is equal to the sum of the torsion constants of the sections: composite sections which constitute the total cross-section. Y and Z moments of inertia Principal moments of inertia of the cross section. Y and Z shear areas Principal shear areas of the cross section, where a value of zero represents an "Infinite" shear area. The shear area is the effective cross sectional area which is used in the calculation of shear deformations. In general, the shear area depends upon the shearing stress distribution, which in turn depends upon the shape of the cross section. For rolled steel sections, the major axis shear area is approximately equal to the area of the web(s). For rectangular cross sections, the shear area is equal to A/1.2, where A is the gross area. Values for other shapes are given in standard textbooks on strength of materials.

For most cross sections and materials, the shear deformations are negligible compared to the flexural deformations. Therefore, the shear area can often be specified as infinite.

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Project Data Principal angle Angle (degrees) from principal axes to geometric axes in anti-clockwise direction. For example, the principal angle is positive for single angle sections that have their horizontal leg pointing to the left. Section mark Member mark used in connection detail drawings, marking plans, etc.

Member cross sections are always shown as if you are looking along the member from the node B end to the node A end. See also Section properties text. See also Datasheet Input. See also Member properties. See also Plate properties. See also View rendered model.

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Standard section libraries Standard sections libraries are available for most countries and they include all I sections, H sections, T sections, channels, angles, square tubes, rectangular tubes and circular tubes. See also Standard library.

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Project Data

Shape builder You can open the shape builder by clicking the button in the Member Properties form of either the renderer or the traditional graphics window.

The shape builder allows you to modify library shapes, combine library, standard and custom shapes into built-up sections, and create standard and custom shapes. Standard shapes are easily created by clicking on one of the standard shapes buttons and entering the desired dimensions. For a custom shape, you are required to enter three or more coordinates and the shape builder will display the shape and calculate the section properties. Inputting shapes To input a shape, you can:

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

Import it from a sections library by clicking the library button



Click the custom shape button define the perimeter of a shape.



Click the line shape button and then enter a set of coordinates to define a shape formed by a line of a user defined thickness. Click one of the standard shape buttons



.

and then enter a set of coordinates to

and then enter its dimensions. Any shape (other than a hollow shape) can be converted to a negative shape (void) by ticking the "Negative shape (hole)" option. This makes it very easy to model voids in your cross section.

Editing and combining shapes You can input up to 10 shapes from any of the above sources and combine them to form your desired cross section. Each shape can be translated, mirrored, rotated or transposed using the shape editing buttons shown below.

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Project Data

Shapes can also be dragged and snapped together via their edge and corner reference points as shown below.

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SPACE GASS 12 User Manual When dragging shapes, the behaviour can be controlled using the grid and snap settings along the bottom of the shape builder as shown below.

Shapes can be copied by dragging while holding down the Ctrl key.

Multiple shapes can be selected by clicking them while holding down the Shift key. You can then use the alignment buttons at the top of the shape builder to align the selected shapes along the top, bottom, center, left or right. Alternatively, you can stack shapes vertically or horizontally using the stack alignment buttons

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Dimensions Dimensions can be added to shapes by clicking the dimensions button

.

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Design properties SPACE GASS can now do a steel member design or check using sections that haven't been imported from a library, however you must specify their steel design properties. You can do this via the shape builder "Design Properties" button. Generally speaking, you would only use the "Design Properties" button when are you don't want to save the section to a library because the saving to library process also includes inputting the steel design properties.

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Project Data

Saving sections You can save your section to a custom library for later recall into any other jobs by clicking the "Save to Library" button appears below.

and then filling out the form that

If a custom section library doesn’t yet exist or if you wish to create a new custom button at the right of the "Library" field and then fill out library, click the the custom library’s details. Similarly, if the library doesn’t yet contain any groups or if you wish to create a new group within a custom library, click the button at the right of the "Group" field and then fill out the group’s details.

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The SPACE GASS section libraries can now contain built-up sections made from whatever shapes you can build in the shape builder, including voids. Built-up or non-standard sections cannot be used in the design/check modules, however they can be recalled into any other jobs and used in a static, dynamic or buckling analysis.

The shape builder always shows the cross section as if you are looking along the member from node A towards node B. This is the reverse of how it was in SPACE GASS 10 and earlier versions.

The section properties displayed in the panel on the right side of the shape builder apply to the whole cross section (ie. the sum of the composite shapes in the display window). See also Member properties. See also View rendered model.

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Flipping a section If the properties of a section have been read from a library, SPACE GASS then asks if the section has been flipped. This simply causes the section to have its major and minor section properties transposed and allows the section to be used in the frame with its major axis parallel to the local y-axis instead of the z-axis. In most cases, the major axis of a member is parallel to its local z-axis (see also Coordinate systems). When a section is flipped, the orientation of the local y and z axes are not affected. This information is not required for sections with equal major and minor axis section properties.

Flipped section orientation

You can see from the diagram above that when the section is flipped, the y and z axes remain unchanged. This method of flipping a section is different to applying a 90 direction angle to a member. A direction angle rotates the local axes together with the section, while the above method simply transposes the section properties. Note that the transposed properties apply to every member which references the flipped section property number, while a direction angle rotation affects only the member(s) to which it is applied.

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Column and beam Tee sections Column Tees have the major axis parallel to the web and are therefore assumed to be lying on their side with their flange vertical (assuming a zero direction angle and no flipping). They are orientated at right angles to normal beam Tees which have the major axis parallel to the flange.

Tee section orientation

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Project Data

Angle sections For angle sections, you can specify single or double angle sections. Choices are:

Single angle, Double angle with short legs connected, Double angle with long legs connected, Double angle starred (equal angles only).

Angle section orientation

The diagrams above show the orientation of a single angle section and the available double angle sections. Note that the z-axis is the major axis in all cases.

For double equal angles, the long leg is assumed to be the vertical leg in the diagrams above. Note that in SPACE GASS 10 and earlier, double equal angle sections with long legs connected were adjusted

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SPACE GASS 12 User Manual internally and treated as though their short legs were connected. This adjustment was removed in SPACE GASS 11 and later versions.

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Project Data

Material property data You can display the material property data for a member by clicking the button in the Member Properties form. The material property data for a plate is always shown in the Plate Properties form.

Material properties must be input for each type of member or plate material in the model. Each material property describes the properties of a single isotropic material. Material There are two fields, one for the material property number and the other for the material name. Material property numbers do not have to be sequential or in any particular order. The material name is used as a description for the material, and as a reference for materials which have been read from a library. E Value of Young’s Modulus for the material.

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Poisson’s Value of Poisson’s Ratio for the material. Mass Dens Mass density, required only for self weight calculations. Temp Coeff The coefficient of thermal expansion, required only for thermal loads. You must ensure that this is appropriate for the temperature units you have selected (see also Units). F’c Characteristic concrete strength, required only for concrete materials. Is used only in the SPACE GASS concrete design modules. See also Material properties text. See also Datasheet Input. See also Member properties. See also Plate properties.

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Master-slave constraint data You can display the master-slave constraints data for a node by clicking the button in the Node Properties form.

Master-slave constraints allow you to connect nodes together with imaginary links so that they translate and/or rotate together. The degree of constraint can be varied so that any or all of the six degrees of freedom of a node can be linked to another node. For example, it is possible to connect two nodes together with a 3D rigid link, a 2D rigid link, a 2D translational link, a 2D rotational link, a 1D translational link, a 1D rotational link or any other combination of the six degrees of freedom.

A node which is linked to another node is termed a "slave node" and the node to which it is linked is termed its "master node". A master node can have many slave nodes, however a slave node can have only one master node. A typical frame can have many slave nodes and many master nodes. A master node cannot be the slave of another master node. A slave node constrained DOF cannot be a support (restraint). A constraint link between a slave node and its master node not only affects the movements of the slave but also the master. Node Slave node to be constrained.

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SPACE GASS 12 User Manual Master node The node to which the slave node is to be constrained. You can select a master node by clicking the "Select" button and then choosing a node. Constraint code Master-slave constraints are controlled by a six character constraint code which specifies the exact constraint relationship between a slave node and its master. The six characters of the constraint code correspond to translational constraint along X, Y and Z and rotational constraint about X, Y and Z respectively. "F" represents fixed (constrained) and "R" represents released (unconstrained). In order to illustrate how the constraint code works, we will consider some typical examples of constraints in the global XY plane. Please note that the following examples apply equally to the XZ and YZ planes also. When considering the XY plane, the only significant characters in the constraint code are the first, second and sixth. These correspond to translation along X and Y, and rotation about Z. When considering the XZ plane, only the first, third and fifth characters apply, and when considering the YZ plane, only the second, third and fourth characters apply. If a slave node has a constraint code of "RFxxxR" (where xxx could be any combination of F’s and R’s) then its Y-axis translation will be the same as its master node. Note that the X-axis translation and the Z-axis rotation of the slave node will be completely independent and in no way affected by its master node. This can be represented by the simple constraint equation Dys = Dym, where Dys is the slave Y-axis translation and Dym is the master Y-axis translation. Similarly, if a slave node has a constraint code of "RRxxxF" then its Z-axis rotation will be the same as its master node and the X-axis and Y-axis translations will be independent. The constraint equation in this case is Rzs = Rzm, where Rzs is the slave Z-axis rotation and Rzm is the master Z-axis rotation. A slightly different situation occurs if both a translational degree of freedom and a rotational degree of freedom are constrained. An example of this is a constraint code of "FFxxxF". In this case, the constraint code effectively places a 2D imaginary rigid member between the slave node and its master so that the translations of the slave node are a function of both the translations and the rotation of the master node. The constraint equations in this case are Dxs = Dxm-Ly*Rzm Dys = Dym+Lx*Rzm Rzs = Rzm

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Project Data where Lx and Ly are the horizontal and vertical components of the distance between the slave and master nodes.

Constraint movements

The following list shows some common constraint codes.

FRRRRR RFRRRR RRFRRR RRRFRR RRRRFR RRRRRF FFFRRR

X translation constrained

(Dxs=Dxm)

Y translation constrained Z translation constrained X rotation constrained Y rotation constrained Z rotation constrained X, Y and Z translations constrained

(Dys=Dym) (Dzs=Dzm) (Rxs=Rxm) (Rys=Rym) (Rzs=Rzm) (Dxs=Dxm) (Dys=Dym)

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RRRFFF

X, Y and Z rotations constrained

FFRRRF

Rigid link in XY plane

FRFRFR

Rigid link in XZ plane

RFFFRR

Rigid link in YZ plane

FFFFFF

Rigid link in all planes

(Dzs=Dzm) (Rxs=Rxm) (Rys=Rym) (Rzs=Rzm) (Dxs=Dxm-Ly*Rzm) (Dys=Dym+Lx*Rzm) (Rzs=Rzm) (Dzs=Dzm-Lx*Rym) (Dxs=Dxm+Lz*Rym) (Rys=Rym) (Dys=Dym-Lz*Rxm) (Dzs=Dzm+Ly*Rxm) (Rxs=Rxm) (Dxs=Dxm-Ly*Rzm+Lz*Rym) (Dys=Dym+Lx*Rzm-Lz*Rxm) (Dzs=Dzm-Lx*Rym+Ly*Rxm) (Rxs=Rxm) (Rys=Rym) (Rzs=Rzm)

Any further combinations of the six character constraint code can also be specified. The following diagrams show the effect that each of the XY plane constraints have. The effects shown apply equally to the XZ and YZ planes also. Note that constraint codes for any of the three planes can be combined together as can be seen in the examples above.

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Project Data

Typical constraint links

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SPACE GASS 12 User Manual Master-slave constraints can be used to great advantage in many structures. They are particularly useful for modelling floor slabs in three dimensional frames. A typical floor slab may displace and rotate in plan as a unit but its plan dimensions do not change due to its large in-plane rigidity. This could be modelled in SPACE GASS by using one of the perimeter nodes in a typical floor slab as the master node for that floor and specifying all of the other perimeter nodes in that floor to be slaves of the master node in the in-plane (XZ plane) directions using a constraint code of "FRFRFR". Thus all nodes in the floor would move as a unit in the inplane (horizontal plane in this case) directions. They would still, however be free to move independently in the out-of-plane (vertical) direction.

Rigid diaphragm modelled with constraints

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Project Data Another example is the case of wind bracing or a scissor lift where two continuous members cross each other and are connected to each other with a bolt or pin. The pin transfers shear from one member to the other but not moment so that the members are free to rotate about the pin independently.

Scissor lift modelled with constraints

This situation is very difficult to model in a frame analysis program unless a constraint facility is available. Using a master-slave constraint, it is a simple matter to locate two nodes on the same point where the two members cross. One of the members would be connected to the first node and the other member would be connected to the second node. Assuming that the frame was in the XY plane, a constraint code of "FFRRRR" could then be used to force the two nodes to translate together but rotate independently. A third example of a common master-slave constraints application is in the modelling of a shear wall. A column of nodes consisting of one master and the rest slaves could be used to form the wall itself. Any other nodes connected directly to the wall could also be slaves of the master. Assuming that the wall was in the XY plane, a constraint code of "FFRRRF" could be used. Another situation which is difficult to model without using a master-slave constraint occurs when two members of different depths are connected together end-to-end such that their centrelines do not line up. In such cases a node could be placed at the end of each member and then a master-slave constraint could be used to join the two nodes together with a rigid link.

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SPACE GASS 12 User Manual In some situations, short stiff members could be used as an alternative to constraint links, however they would be susceptible to ill-conditioning problems, particularly if they were very stiff in comparison to other members in the structure.

Master-slave constraints do not suffer from ill-conditioning problems, regardless of how short the links are. See also Master-slave constraints text. See also Datasheet Input. See also Node properties. See also View node / member / plate properties.

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Project Data

Member offset data You can display the offsets data for a member by clicking the Member Properties form.

Choices are:

button in the

Local, Global.

It is possible to specify a rigid member segment that doesn’t deform under bending at each end of a member. These rigid segments have infinite stiffness for bending, shear and axial deformations. Member offsets are very useful for modelling the very stiff area at the interconnection of members (especially stiff members such as large steel members or concrete members).

Member offsets

For example, the rectangular reinforced concrete frame shown above on the left could be modelled quite accurately with SPACE GASS using a model similar to the one shown on the right. Each member in the model has short member offsets at each end where intersecting members overlap.

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Member offsets are also very useful in situations where the centrelines of connected members do not intersect at a node. For example, the diagonal brace members of a plane truss may intersect below the top chord centreline. Member offsets could be used to allow for this. Member offsets could also be used to model the centreline mismatch when members of different depths are connected end-to-end with "top-of-steel" alignment.

The ends of a member with "local" offsets are offset relative to an axis connecting the end nodes of the member rather than being relative to the axis of the member in its final position. ! IMPORTANT NOTE ! Be careful when sub-dividing members that have local offsets because the direction of the axis that the offsets are relative to will change when any intermediate nodes are added. See also Member offset text. See also Datasheet Input. See also Member properties. See also View node / member / plate properties.

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Project Data

Node load data

Concentrated forces and moments may be applied to any node along or about the global X, Y and Z axis directions. If a load is applied to a restrained degree of freedom then that load is simply added to the final reaction. Node loads may be applied in any number of load cases and may be combined with other load types within the same load case. Case Load case to contain node loads. Node Node to be loaded. X, Y and Z forces Node forces (global axes). X, Y and Z moments Node moments (global axes). See also Node loads text. See also Datasheet Input. See also Node loads. See also View diagrams.

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Prescribed node displacement data

Prescribed node displacements allow you to specify known displacements and/or rotations to nodes. They can be very useful for situations where a frame deflects by a fixed and known amount such as settlement of a support for example.

Prescribed displacements may only be applied to restrained (fixed or deleted) degrees of freedom, otherwise they are ignored. Prescribed node displacements may be applied in any number of load cases and may be combined with other load types within the same load case. It is important to note that like all other load types, prescribed node displacements do not have any effect on load cases other than the ones in which they are input. Case Load case to contain prescribed displacements. Node Node to be displaced. X, Y and Z translations Node translations (global axes). X, Y and Z rotations Node rotations (global axes). See also Prescribed node displacements text.

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Project Data See also Datasheet Input. See also Prescribed node displacements. See also View diagrams.

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Member concentrated load data

Concentrated forces and moments may be applied to members in either the global or the local axes systems. Such loads can act along or about any of the three axis directions and can be located at any point along the member. Member concentrated loads may be applied in any number of load cases and may be combined with other load types within the same load case. Case Load case to contain concentrated member loads. Member Member to be loaded. Sub load This allows you to reference multiple concentrated loads on a member in the same load case. Each load is given a sub load number (different to a load case number). For example five concentrated loads applied to a member within the same load case would have sub load numbers of 1,2,3,4 and 5 respectively. Unless there are multiple loads applied to a single member within the same load case, the sub load number should be 1. Axes Axes system in which loads are referenced. Choices are:

Local, Global.

Units Units system in which load positions are referenced.

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Choices are:

Actual, Percentage.

Position The load position is defined as the distance from node A to the load. Depending on the "Units system" selected, this distance may be expressed as an absolute length or as a percentage of the member length. Thus, a member 600mm long with a load at midspan could have the load position specified as 300mm or as 50%. X, Y and Z forces Member concentrated forces. X, Y and Z moments Member concentrated moments. See also Member concentrated loads text. See also Datasheet Input. See also Member concentrated loads. See also View diagrams.

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Member distributed force data

Member distributed forces can be input in the local or global axes systems and can act along any of the three axis directions. Distributed forces may start and finish at any point along the member length and may vary in intensity from start to finish. Thus, it is possible to apply uniform, trapezoidal, or triangular distributed loads. Member distributed forces may be applied in any load case and may be combined with other load types within the same load case. ! IMPORTANT NOTE ! For "Local" or "Global Inclined" loads, the total load is equal to the load per unit length multiplied by the actual distance between the load start and finish positions. For "Global Projected" loads, the total load is equal to the load per unit length multiplied by the projected distance between the load start and finish positions. ! IMPORTANT NOTE ! For cable members, distributed forces must be uniform and extend over the entire length of the cable. For "Global Inclined" UDLs applied to cable members, the total load is equal to the load per unit length multiplied by the unstrained cable length (which may not be equal to the distance between the cable’s end nodes). For "Global Projected" UDLs applied to cable members, the total load is equal to the load per unit length multiplied by the projected distance between the cable’s end nodes. Case Load case to contain distributed member forces.

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Project Data Member Member to be loaded. Sub load This allows you to reference multiple distributed loads on a member in the same load case. Each load is given a sub load number (different to a load case number). For example two distributed loads applied to a member within the same load case would have sub load numbers of 1 and 2 respectively. Unless there are multiple loads applied to a single member within the same load case, the sub load number should be 1. Axes Axes system in which loads are referenced. There are two global axes systems which may be used. When the axes are designated as "Global projected" the load acts over the projected length of the member, while a "Global inclined" load acts over the actual length of the member. Choices are:

Local, Global projected, Global inclined.

Units Units system in which load positions are referenced. Choices are:

Actual, Percentage.

Start and finish positions The load start and finish positions are taken relative to node A. Depending on the "Units system" selected, this distance may be expressed as an absolute length or percentage of the member length. Thus, a member 600mm long with a load that extends from the 150mm mark to the end could have the load start position specified as 150mm or as 25%, and the load finish position specified as 600mm or as 100%. The finish position must always be greater than start. X, Y and Z start and finish forces Start and finish member distributed forces. See also Member distributed forces text. See also Datasheet Input. See also Member distributed forces.

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SPACE GASS 12 User Manual See also View diagrams. See also Cable members.

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Project Data

Member distributed torsion data

Member distributed torsion loads are similar to member distributed forces except they may only be applied about the local x-axis. The load intensity may be varied between the start and finish positions. Member distributed torsions may be applied in any load case and may be combined with other load types within the same load case. Case Load case to contain distributed member torsions. Member Member to be loaded. Sub load This allows you to reference multiple distributed torsions on a member in the same load case. Each load is given a sub load number (different to a load case number). For example two distributed torsions applied to a member within the same load case would have sub load numbers of 1 and 2 respectively. Unless there are multiple loads applied to a single member within the same load case, the sub load number should be 1. Units Units system in which load positions are referenced. Choices are:

Actual,

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SPACE GASS 12 User Manual Percentage. Start and finish positions The load start and finish positions are taken relative to node A. Depending on the "Units system" selected, this distance may be expressed as an absolute length or percentage of the member length. Thus, a member 600mm long with a load that extends from the 150mm mark to the end could have the load start position specified as 150mm or as 25%, and the load finish position specified as 600mm or as 100%. The finish position must always be greater than start. Start and finish torsion load Start and finish member distributed torsion load. See also Member distributed torsions text. See also Datasheet Input. See also Member distributed torsions. See also View diagrams.

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Project Data

Thermal load data

A thermal load can be applied to a member by specifying a temperature change, while a thermal load can be applied to a plate in the form of a temperature change or a thermal gradient across its thickness. Thermal loads act over the entire length of the members or area of the plates to which they are applied. Thermal loads may be applied in any load case and may be combined with other load types within the same load case. Case Load case to contain thermal loads. Element Member or plate to be loaded. Thermal load Uniform temperature change. Thermal gradient (plates only) Thermal gradient across plate thickness. A positive thermal gradient causes the top (positive z-axis) face of the plate to expand and the bottom face to contract.

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Unlike other load types, you can apply thermal loads to non-existent members or plates without causing an analysis error. Such loads are simply ignored during the analysis phase. For example, in order to apply a uniform 10 temperature change to an entire structure with a highest member number of less than 100, you could simply generate 10 thermal loads on members 1-100 without concerning yourself about possible gaps in the member numbering sequence. See also Thermal loads text. See also Datasheet Input. See also Thermal loads. See also View diagrams.

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Member prestress data

A prestress can be applied to a member by specifying a tensile or compressive force. Prestress loads act over the entire length of the members on which they are applied. It is possible to model prestress loads with equivalent thermal loads and vice-versa, however this is generally unnecessary because they can both be applied directly in SPACE GASS. Prestress loads may be applied in any load case and may be combined with other load types within the same load case.

Note that the prestress load you apply to a member is not likely to be the final axial force in the member at the end of the analysis (unless its ends are fixed in position or don't move). This is because the axial force changes as the member stretches or compresses as its end nodes move. If you wish to achieve a particular axial force at the end of the analysis then a trial and error process is required. This involves setting an initial prestress force, performing the analysis, checking the final axial force, adjusting the prestress and repeating the process until the desired axial force is achieved. This is a common requirement in post-tensioned concrete applications where the tendons are jacked to a known tension.

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SPACE GASS 12 User Manual Case Load case to contain prestress loads. Member Member to be loaded. Prestress force The prestress force is positive for compression or negative for tension. In some instances, you may wish to apply a prestress load to a cable member instead of specifying a non-zero unstrained cable length. The prestress load P that is equivalent to an unstrained cable length L is given by the equation:

where

D = chord length, A = cross sectional area, E = Young’s modulus of elasticity.

See also Member prestress loads text. See also Datasheet Input. See also Member prestress loads. See also Cable members. See also View diagrams.

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Project Data

Plate pressure data

Pressure loads may be applied to plates in either the global or the local axes systems. Such loads can act along or about any of the three axis directions and always extend over the entire plate surface. Plate pressure loads may be applied in any number of load cases and may be combined with other load types within the same load case. Case Load case to contain plate pressure loads. Plate Plate to be loaded. Axes Axes system in which loads are referenced. Choices are:

Local, Global.

X, Y and Z pressure Plate pressure loads.

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SPACE GASS 12 User Manual Plate pressure loads can be input graphically as explained in Plate pressure loads or, for variable pressure loads such as hydrostatic or wind loads, the Varying plate pressure loads tool can be used. See also Plate pressure loads text. See also Datasheet Input. See also Plate pressure loads. See also Varying plate pressure loads. See also View diagrams.

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Project Data

Self weight data

Self weight loads are considered as forces and moments in a static analysis and as masses in a dynamic analysis. Self weight can be automatically generated by the program if an acceleration (such as gravity) is specified. Acceleration may be specified along any of the three global axis directions. Note that self weight will only be considered if non-zero mass densities are specified in the material property data. When self weight loads are used as masses in a dynamic analysis, the direction and magnitude of the X, Y and Z accelerations are ignored. The process simply involves calculating the mass of each member and then applying half of it as translational lumped masses to each of the member end nodes in each of the unrestrained X, Y and Z global axis directions. Self weight may be applied in any load case and may be combined with other load types within the same load case. Case Load case to contain self weight.

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SPACE GASS 12 User Manual X, Y and Z acceleration Acceleration applied to the entire structure. See Units for the appropriate acceleration units that apply. See also Self weight text. See also Datasheet Input. See also Self weight. See also Cable members.

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Project Data

Combination load case data

All loads applied to a structure are always input via primary load cases. Further load cases can be created by combining the various primary load cases into combination load cases.

Combination load cases can be combined into further combination load cases. Combination case Load case to be formed. Cannot be equal to a primary load case. Case Load case to be factored and combined into the combination. This can be a primary load case or a combination load case. Multiplying factor The multiplying factor applied to the primary load case when it is combined. Consider for example a structure that is to be analysed for the following combination load cases 10, 11 and 12.

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SPACE GASS 12 User Manual Load case 1: Load case 2: Load case 3: Load case 4: Load case 5: Load case 20: Load case 21: Load case 22: where

Self weight (SW) Floor load (LL1) Roof traffic (LL2) Cladding (CL) Wind load (WL) 1.25*DL + 1.50*LL 0.80*DL + 1.50*LL 0.80*DL + 1.00*WL, DL = SW + CL LL = LL1 + LL2

The desired combination load cases could then be made up as follows. Load case 10 (DL): Load case 11 (LL): Load case 20: Load case 21: Load case 22:

1.00*Load case 1 + 1.00*Load case 4 1.00*Load case 2 + 1.00*Load case 3 1.25*Load case 10 + 1.50*Load case 11 0.80*Load case 10 + 1.50*Load case 11 0.80*Load case 10 + 1.00*Load case 5

Note that for a linear analysis, it is not necessary to analyse the combination load cases. They can be calculated by simple linear superposition of the primary load case results during the output phase. For a non-linear (2nd order) analysis however, the simple linear superposition rules don’t apply and combination load cases have to be fully analysed and treated in the same way as primary load cases. For this reason, SPACE GASS allows you to decide whether or not to analyse the combination load cases and treat them the same as primary load cases or to not analyse them and have them calculated by simple linear superposition during the output phase. You can specify the load cases that you want analysed by listing them at the start of the analysis phase. For example, if you have primary load cases 1,2,3 and 4, and combination load cases 10,11 and 12, you could analyse just the primaries by entering 1-4 for the load cases list.

If you are doing a dynamic response analysis, you should create a reverse combination load case for each spectral load case. You may also have to create further combinations to combine the spectral load cases with different direction vectors. For more information refer to Spectral load data.

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Project Data

SPACE GASS will not allow a combination load case to be a simple linear combination of analysed primary load cases if any of the primaries have been analysed non-linearly or if the frame contains tension-only or compression-only members. In this case the combination load case must be analysed. You can modify the combination load case data and obtain new results without re-analysing the structure, however this only applies to linear superposition combinations. Results for analysed combinations are deleted if the combination load case data is changed. See also Combination load cases text. See also Datasheet Input. See also Combination load cases.

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Load case title data

Load case titles serve the purpose of creating clearer, more understandable output. Primary or combination load cases may be given titles. Case Load case to have title defined. Title A description of the load case. Notes Notes that allow you to describe the load case in more detail. See also Load case titles text. See also Datasheet Input.

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Project Data

Lumped mass data

Lumped masses are considered in a dynamic analysis and are ignored in a static analysis. Translational or rotational masses can be applied to any node along or about the global X, Y and Z axis directions. If a mass is applied to a restrained degree of freedom then that mass is simply ignored during the dynamic frequency analysis. Masses may be applied in any load cases and may be combined with static loads within the same load case, although it is often a good idea to put masses in load cases of their own (ie. not in with static loads) so that they can be isolated in graphics displays or output reports. Self mass can be added to the lumped masses by either by adding self-weight to a load case that contains lumped masses or by combining lumped mass and selfweight load cases into a combination load case. Case Load case to contain lumped masses. Node Node to have masses applied. X, Y and Z translational masses Translational masses (global axes). X, Y and Z rotational masses Rotational masses (global axes).

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The application of lumped masses A mass that affects the natural frequencies of a structure must be applied in each of the unrestrained directions of the node to which it is attached. For example, a 0.5 tonne machine which is attached to a point on a building rafter has an inertia in each of the X, Y and Z directions and effects the natural frequencies of the building in all three directions. It must therefore be applied as 0.5 tonne X, Y and Z translational masses. ! IMPORTANT NOTE ! Lumped masses are not the same as loads and therefore cannot be calculated by simply converting loads to mass units. Masses represent the structure and/or attachments to the structure which move and rotate with it and which effect its natural frequencies. Some types of loads would have to be input as lumped masses while others would not. For example, dead loads and 30-100% of live loads would normally affect the natural frequencies of a structure, however wind loads would not. The inertia of the structure could be modelled in one of the following two ways: Translational masses Consider a rigid floor slab. You could model the distribution of mass by placing a small translational mass at each node in the slab (the sum of all node masses equalling the total mass of the slab). Translational and rotational masses You could also model the rigid floor slab by lumping all of the translational mass and a rotational mass at the centroid of the slab. In the first approach, the rotational inertia would be provided by the action of each of the small translational masses being a distance away from the centroid of the slab. In the second approach, the rotational inertia would be provided directly by the rotational mass at the centroid of the slab. It is usually more convenient and just as accurate to use the second approach. The rotational mass for a point at the centroid of a rectangle is

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Project Data where m is the mass of the rectangle, and a and b are the dimensions of the rectangle. The concept of rotational mass, together with formulae for calculating rotational masses at various locations on rectangles and other shapes, is given in Clough and Penzien (10). Self mass It is not necessary to manually input lumped masses for the self mass of the structure because self mass can automatically be considered by simply adding selfweight to one or more load cases. However, automatic self mass generation does not calculate rotational masses because of the large number of extra masses that would be generated for a fairly insignificant improvement in results accuracy. If required, rotational self mass must be manually applied as rotational lumped masses. In order to adequately define the distribution of mass along members for which local vibrations are important, it is sometimes necessary to add intermediate nodes (with masses applied) to such members. See also Lumped masses text. See also Self-weight. See also Datasheet Input. See also Lumped masses. See also View diagrams. See also Dynamic frequency analysis. See also Running a dynamic frequency analysis.

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Spectral load data

In order to perform a response spectrum analysis, you must first create one or more spectral load cases. A spectral load case contains the number of a mass load case, a direction vector and a list of mode shapes, each with its associated spectral curve and damping factor. Spectral load cases can be combined and multiple spectral load cases can be analysed simultaneously.

The mode shapes must have been calculated from a dynamic frequency analysis before the response spectrum analysis can proceed. Case The spectral load case being created (see also "load cases" below). Mode A mode shape being included in the spectral load case. Multiple mode shapes can be included in a single spectral load case by simply inputting multiple entries (lines) with the same spectral load case number. A particular mode shape can appear only once in each spectral load case. In the spectral analysis, it is important to consider a sufficient number of mode shapes. SPACE GASS provides a very efficient means of measuring the contribution of each mode shape in the overall dynamic response. This is known as the mass participation factor. For example, for an earthquake acting in the X direction, the total X-axis mass participation factor should be greater than 90% (AS1170.4 clause 7.4.2). If it is less than 90% then a few more mode shapes should be included in the analysis. A small mass participation factor will indicate

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Project Data inaccurate results. For more information, refer to "Dynamic response analysis results". Spectral curve The name of the spectral curve to be used with the specified mode shape. Normally all mode shapes in a spectral load case use the same spectral curve, however you can nominate different spectral curves for each mode if desired. Damping The damping factor associated with the nominated spectral curve. This value is built into each spectral curve when it was derived and cannot be changed. It is included in the datasheet for display purposes only. Mass case The mass load case for which the specified mode shapes have been (or will be) calculated from a dynamic frequency analysis. Direction vector Defines the direction of the ground vibration. For example, an earthquake acting in the X direction would have a direction vector of Dx=1.0, Dy=0.0 and Dz=0.0. Note that for AS1170.4 and NZS4203, if auto-scaling of the base shear is activated, the direction vector should be parallel to one of the horizontal global axes. For these codes, to model a direction vector that is at an angle to the horizontal global axes, you should create a separate spectral load case for each of the horizontal global axis directions and then combine them into a combination load case using multiplying factors that are proportional to the projected lengths of the desired direction vector. Load cases For building structures, it is common to input two spectral load cases per mass load case, one for each of the orthogonal horizontal directions. Furthermore, if the loading code requires you to consider a combination of the two orthogonal directions (ie. AS1170.4-2007 5.4.2.1 or NZS1170.5-2004 5.3.1) then further load cases may also be required. Finally, because the dynamic vibrations oscillate from one side to the other, it is also necessary to consider the reverse of all of the above load cases. For example, consider two basic spectral load cases defined for a particular mass load case as follows: Load case 21 = Direction vector 1,0,0 (ie. earthquake in X-axis direction)

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SPACE GASS 12 User Manual Load case 22 = Direction vector 0,0,1 (ie. earthquake in Z-axis direction) If the loading code requires further combinations of the above load cases in the form of 100% of the actions in one direction plus 30% of the actions in the perpendicular direction then further load cases are required. These are most conveniently input as combination load cases as follows: Load case 23 = 1.0 x case 21 + 0.3 x case 22 Load case 24 = 1.0 x case 21 - 0.3 x case 22 Load case 25 = 1.0 x case 22 + 0.3 x case 21 Load case 26 = 1.0 x case 22 - 0.3 x case 21 Finally, the reverse of the all the above load cases must be defined as further combination load cases as follows: Load case 31 = -1.0 x Load case 21 Load case 32 = -1.0 x Load case 22 Load case 33 = -1.0 x Load case 23 Load case 34 = -1.0 x Load case 24 Load case 35 = -1.0 x Load case 25 Load case 36 = -1.0 x Load case 26 Thus, each pair of basic spectral load cases can spawn up to a further ten combination load cases. The structure should be designed to resist the envelope of all load cases.

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Project Data

Spectral curve editor You can open the spectral curve editor by opening the "Spectral Load Data" datasheet from the Loads menu and then clicking the

button.

You can select the desired spectral curve from the tree in the left-hand window and observe its data values in the right-hand window. You can also click the spectral curve editor button (next to the Ok button) to load and display the spectral curve editor as shown below.

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The spectral curve editor can be used to input or edit curves in the spectral curve library. Note, however, that the standard curves supplied with SPACE GASS can’t be changed. The editor allows you to create a spectral curve that will result in the most accurate analysis possible. Operation of the spectral curve editor is self-explanatory and simply involves selecting a curve name and then inputting or modifying its properties. Each curve contains a set of period versus acceleration pairs, a description and a damping factor. You can go to a specific point in a curve by clicking near it in the graphics window or by scrolling to and selecting it in the list box. The currently selected point in the list box is highlighted by a small circle in the graphics window. You can add (or delete) points by clicking the buttons below the list box. See also Standard Libraries for general information about the operation of the library editor.

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Project Data

Importing a spectral curve You can import a spectral curve directly into the spectral curve editor by rightclicking the spectral library that you want to import the curve into and selecting "From Text File" or "From Excel". Note that you can't import into a standard library and so you have to create a custom spectral library first. You can do this by clicking the "Add Library" button near the bottom of the form. In order to successfully import a spectral curve into the spectral curve editor you must ensure that you use the correct format in the text or Excel file. You can create a text or Excel file to use as a pattern for creating your own file by simply exporting one of the standard spectral curves. Right-click on one of the existing curves and then choose the "Export..." option to do this. The correct format is as follows: Line 1 Line 2 Line 3 Line 4 …etc. …etc. Line n Line n+1

Description:Damping factor period,acceleration period,acceleration period,acceleration

{for point 1} {for point 2} {for point 3}

period,acceleration period,acceleration

{for point n-1} {for point n}

For example: AS1170.4 S=1.0:5% 0.00,2.5 0.01,2.5 0.02,2.5 … … 2.99,0.602276 3.00,0.600937 See also Spectral loads text.

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SPACE GASS 12 User Manual See also Datasheet Input. See also Dynamic response analysis. See also Running a dynamic response analysis.

222

Project Data

Area load data

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Project Data

The area loads tool generates member distributed forces based on pressure loads applied to areas defined by members that you have selected. For more information see Area loads and Member distributed forces.

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Sea load data

This tool lets you generate wave and ocean current loads on submerged structures in marine and offshore environments where these effects impose significant loading on the affected structure. For more detailed information refer to "Sea Loads".

226

Project Data

Moving load data

The moving loads tool generates node loads and member concentrated loads based on one or more moving vehicles. For more information refer to "Moving loads", "Node load data" and "Member concentrated load data".

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Text File Input Text file input Select "Import from text" or "Export to text" from the File menu Inputting data into SPACE GASS via a text file is sometimes faster than using datasheet input, however it is not as user friendly and is not recommended for first time users of SPACE GASS. You can use Windows Notepad to edit or create text files. The text editor linked to SPACE GASS can be started by choosing "Text editor" from the File menu. SPACE GASS text file names have the form .TXT, where is any name. The text file should be located in the text data folder as created during the installation procedure. If a large proportion of the data for a job has to be modified and you do not wish to use the normal editing facilities, the data can be put into a text file which can then be edited using a word processor or text editor, and then imported back into SPACE GASS.

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Text file format Each data group in a SPACE GASS text file must be preceded by a title line. The title line describes the type of data in the lines to follow. For example, the node data would be preceded by "NODES". When reading text files the program uses only the first six characters of each title line, therefore when creating text files you can abbreviate title lines to their first six characters. It is possible to repeat data throughout the data file. Single items or whole groups can be repeated. In such cases the last entry overrides any previous entries. For example, if node coordinates were entered at the top of the file and then updated at the end, the last group would override the first. This practice, however is not recommended. Groups of data do not have to be input in any particular order. The program recognises the data types by their title lines rather than their order of appearance.  

    

Items within a line must be separated by commas. Lines can be continued on the next line if they end with the "&" character. The maximum length of a single line is 1024 characters. The maximum length of a set of continued lines is 2048 characters. Comment lines must begin with the "#" character. Blank lines are permitted anywhere in the file. Non-numeric items that contain commas must be enclosed in "quotes".

Real numbers in SPACE GASS text files no longer need to contain a decimal point. Furthermore, all numbers in SPACE GASS text files can now be up to 15 digits long (they were previously limited to 10 digits).

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Text File Input

Initiator Line 1: Line 2:

SPACE GASS Text File - Version 900 UNITS LENGTH:Len, SECTION:SecProp, STRENGTH:MatStr, DENSITY:Dens, TEMP:Temp, FORCE:Force, MOMENT:Mom, MASS:Mass, ACC:Acc, TRANS:Trans, STRESS:Stress

Len SecProp MatStr

Length units (ft, in, m, cm or mm) Section property units (ft, in, m, cm or mm) Material strength units (Ksf, Psf, Ksi, Psi, MPa, kPa, Pa, kg/m^2, kg/cm^2, kg/mm^2) Mass density units (K/ft^3, K/in^3, lb/ft^3, lb/in^3, T/m^3, T/cm^3, T/mm^3, kg/m^3, kg/cm^3, kg/mm^3) Temperature units (Fahrenheit, Celsius) Force units (K, lb, kN, N, kg) Moment units (Kft, Kin, lbft, lbin, kNm, kNcm, kNmm, Nm, Ncm, Nmm, kgm, kgcm, kgmm) Mass units (K, lb, T, kg) Acceleration units (g's, ft/sec^2, in/sec^2, m/sec^2, cm/sec^2, mm/sec^2, kN/kg) Translation units (ft, in, m, cm, mm) Stress units (Ksf, Psf, Ksi, Psi, MPa, kPa, Pa, kg/m^2, kg/cm^2, kg/mm^2)

Dens

Temp Force Mom

Mass Acc

Trans Stress

(Chars) (Chars) (Chars)

(Chars)

(Chars) (Chars) (Chars)

(Chars) (Chars)

(Chars) (Chars)

See also Units.

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Headings text Line 1: Line 2: Line 3: Line 4: Line 5:

HEADINGS Project Job Designer Notes

Project Job Designer Notes

Project description Job description Designer’s initials Job notes

(50 Char) (50 Char) (3 Char) (1024 Char)

If any of the heading lines have no data then they should be entered as just a pair of quotes (eg. "") rather than just being a blank line. See also Headings.

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Text File Input

Nodes text Line 1: NODES Next n Node,X,Y,Z,Gen1,Ndi1,Rot,Ai,Xi1,Yi1,Zi1, lines: Gen2,Ndi2,Xi2,Yi2,Zi2 Node X Y Z Gen1 Ndi1 Rot Ai Xi1 Yi1 Zi1 Gen2 Ndi2 Xi2 Yi2 Zi2

Node number X coordinate Y coordinate Z coordinate # of 1st order nodes to be generated 1st order node number increment Axis of rot. for arc or helix generation (X/Y/Z) Angle increment for arc or helix generation 1st order X increment 1st order Y increment 1st order Z increment # of 2nd order nodes to be generated 2nd order node number increment 2nd order X increment 2nd order Y increment 2nd order Z increment

(Integer) (Real) (Real) (Real) (Integer) (Integer) (1 Char) (Real) (Real) (Real) (Real) (Integer) (Integer) (Real) (Real) (Real)

For straight line generation, Ai should be zero. For arc or helix generation, Rot is the axis of rotation, Ai is the angle increment and Xi1, Yi1, Zi1 are the centre of rotation and the helix length increment. For example, if a helix is generated about the Y-axis, then Yi1 is the helix length increment. For arc generation the helix length increment is 0. Rot choices are "X"=X-axis, "Y"=Y-axis, "Z"=Z-axis. See also Nodes.

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Members text Line 1: Next n lines:

MEMBERS Mem,DirAng,DirNode,DirAxis,Type,Na,Nb,Sp,Mp, Fa,Fb,Ya,SZa,SYb,SZb,Cab,Gen1,Mbi1,Nai1,Nbi1, Gen2,Mbi2,Nai2,Nbi2

Mem DirAng DirNode DirAxis Type Na Nb Sp Mp Fa Fb SYa SZa Syb SZb Cab Gen1 Mbil Nail Nbil Gen2 Mbi2 Nai2 Nbi2

Member number Direction angle Direction node Direction axis Member type (N/T/C/A) Node number A Node number B Section property number Material property number Node A fixity (F/R/S) Node B fixity (F/R/S) Y rotational stiffness at node A Z rotational stiffness at node A Y rotational stiffness at node B Y rotational stiffness at node B Cable length # of 1st order members to be generated 1st order member number increment 1st order node A increment 1st order node B increment # of 2nd order members to be generated 2nd order member number increment 2nd order node A increment 2nd order node B increment

(Integer) (Real) (Integer) (2 Char) (1 Char) (Integer) (Integer) (Integer) (Integer) (6 Char) (6 Char) (Real) (Real) (Real) (Real) (Real) (Integer) (Integer) (Integer) (Integer) (Integer) (Integer) (Integer) (Integer)

Type choices are "N"=Normal, "T"=Tension-only, "C"=Compression-only, "A"=Cable. Fa, Fb choices are "F"=Fixed, "R"=Released. "S"=Spring can also be used for the y and z rotational fixities.

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Text File Input See also Members.

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Plates text Line 1: Next n lines:

PLATES Plate,DirAng,DirNode,DirAxis,Type,Na,Nb,Nc,Nd, TA,TM,TB,TS,Mat,Offset,Gen,PInc,NInc

Plate DirAng DirNode DirAxis Type Na Nb Nc Nd TA TM TB TS Mat Offset Gen PInc NInc

Plate number Direction angle Direction node Direction axis Plate type (K/M) Node number A Node number B Node number C Node number D Actual thickness Membrane thickness Bending thickness Shear thickness Material property number Plate offset # of plates to be generated Plate number increment Node number increment

Type choices are "K"=Kirchoff (thin), "M"=Mindlin (thick). See also Plates.

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(Integer) (Real) (Integer) (2 Char) (1 Char) (Integer) (Integer) (Integer) (Integer) (Real) (Real) (Real) (Real) (Integer) (Real) (Integer) (Integer) (Integer)

Text File Input

Node restraints text Line 1: RESTRAINTS Next n Node,Rest,Gr,Gen,NInc,Ax,Ay,Az,Rx,Ry,Rz lines: Node Rest Gr Gen NInc Ax Ay Az Rx Ry Rz

Node number Restraint code (F/R/D/S) General restraint (Y/N) # of restrained nodes Node number increment X axial spring stiffness Y axial spring stiffness Z axial spring stiffness X rotational spring stiffness Y rotational spring stiffness Z rotational spring stiffness

(Integer) (6 Char) (1 Char) (Integer) (Integer) (Real) (Real) (Real) (Real) (Real) (Real)

Rs choices are "F"=Fixed, "R"=Released, "D"=Deleted, "S"=Spring. Gr choices are "Y"=General restraint, " " or "N"=Normal restraint. See also Node restraints.

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Section properties text Line 1: SECTIONS Next n Sec,Secn,Lib,Ast,Mark,Flip,Ar,Ix,Iy,Iz,Ay,Az,Pa, lines: Scs,Dpth,Wdth,Fw,Ft,Hf Note that Dpth,Wdth,Fw,Ft and Hf are only required if Scs is R,C,T,L or I Sec Secn Lib Ast Mark Flip Ar Ix Iy Iz Ay Az Pa Scs Dpth Wdth Fw Ft Hf

Section property number Section name Section library name Angle section type (A/S/L/X) Section mark Section flipped (Y/N) Area of section Torsion constant Y moment of inertia Z moment of inertia Y shear area Z shear area Principal angle Standard shape (R/C/T/L/I) Overall depth or diameter Overall width or web width Flange width if T-beam or L-beam Flange thickness if T-beam or L-beam Height to bot. of flange if T-beam or L-beam

(Integer) (15 Char) (8 Char) (1 Char) (5 Char) (1 Char) (Real) (Real) (Real) (Real) (Real) (Real) (Real) (1 Char) (Real) (Real) (Real) (Real) (Real)

Ast choices are " "=Not an angle section, "A"=Single angle, "S"=Double angle with short legs connected, "L"=Double angle with long legs connected, "X"=Double starred angle. Flip choices are "Y"=Flipped, " " or "N"=Not flipped. Scs choices are " "=Not a standard shape, "R"=Rectangle, "C"=Circle, "T"=Tbeam, "L"=Left L-beam, "I"=Right L-beam. If Scs is blank, the section is assumed to come from Ar, Ix, Iy, Iz, Ay, Az and Pa.

238

Text File Input

See also Section properties.

239


Material properties text Line 1: Next n lines:

MATERIALS Mat,Matl,E,Pr,D,T,Fc

Mat Matl Lib E Pr D T Fc

Material property number Material name Material library name Young’s modulus Poisson’s ratio Mass density Coefficient of thermal expansion Characteristic concrete strength

See also Material properties.

240

(Integer) (15 Char) (8 Char) (Real) (Real) (Real) (Real) (Real)

Text File Input

Master-slave constraints text Line 1: Next n lines:

CONSTRAINTS SNode,MNode,Cnst,Gen,SInc,MInc

SNode MNode Cnst Gen SInc MInc

Slave node number Master node number Constraint code (F/R) # of slave nodes to be generated Slave node number increment Master node number increment

(Integer) (Integer) (6 Char) (Integer) (Integer) (Integer)

Cc choices are "F"=Fixed, "R"=Released. See also Master-slave constraints.

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Member offset text Line 1: OFFSETS Next n Mem,Ax,Dxa,Dya,Dza,Dxb,Dyb,Dzb lines: Mem Ax Dxa Dya Dza Dxb Dyb Dzb

Member number Axes system (L/G) Member offset from A along x-axis Member offset from A along y-axis Member offset from A along z-axis Member offset from B along x-axis Member offset from B along y-axis Member offset from B along z-axis

Ax choices are "L"=Local, "G"=Global. See also Member offsets.

242

(Integer) (1 Char) (Real) (Real) (Real) (Real) (Real) (Real)

Text File Input

Node loads text Line 1: NODELOADS Next n Case,Node,Fx,Fy,Fz,Mx,My,Mz,Gen,NInc lines: Case Node Fx Fy Fz Mx My Mz Gen NInc

Load case number Node number X force Y force Z force X moment Y moment Z moment # of loaded nodes to be generated Node number increment

(Integer) (Integer) (Real) (Real) (Real) (Real) (Real) (Real) (Integer) (Integer)

See also Node loads.

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Prescribed node displacements text Line 1: NODEDISPS Next n Case,Node,Tx,Ty,Tz,Rx,Ry,Rz,Gen,NInc lines: Case Node Tx Ty Tz Rx Ry Rz Gen NInc

Load case number Node number X translation Y translation Z translation X rotation Y rotation Z rotation # of displaced nodes to be generated Node number increment

See also Prescribed node displacements.

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Text File Input

Member concentrated loads text Line 1: MEMBCONC Next n Case,Mem,Sl,Ax,Un,Ps,Fx,Fy,Fz,Mx,My,Mz, lines: Gen1,MInc,Gen2,SInc,PInc Case Mem Sl Ax Un Ps Fx Fy Fz Mx My Mz Gen1 MInc Gen2 SInc PInc

Load case number Member number Sub load number Axes system (L/G) Units system (A/%) Load position X force Y force Z force X moment Y moment Z moment # of loaded members to be generated Member number increment # of loads per member to be generated Sub load number increment Load position increment

(Integer) (Integer) (Integer) (1 Char) (1 Char) (Real) (Real) (Real) (Real) (Real) (Real) (Real) (Integer) (Integer) (Integer) (Integer) (Real)

Ax choices are "L"=Local, "G"=Global. Un choices are "A"=Actual, "%"=Percentage. See also Member concentrated loads.

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Member distributed forces text Line 1: MEMBFORCES Next n Case,Mem,Sl,Ax,Un,St,Fi,Xs,Xf,Ys,Yf,Zs,Zf, lines: Gen,MInc Case Mem Sl Ax Un St Fi Xs Xf Ys Yf Zs Zf Gen MInc

Load case number Member number Sub load number Axes system (L/G/A) Units system (A/%) Start position Finish position X start force X finish force Y start force Y finish force Z start force Z finish force # of loaded members to be generated Member number increment

(Integer) (Integer) (Integer) (1 Char) (1 Char) (Real) (Real) (Real) (Real) (Real) (Real) (Real) (Real) (Integer) (Integer)

Ax choices are "L"=Local, "G"=Global-projected, "A"=Global-inclined. Un choices are "A"=Actual, "%"=Percentage. See also Member distributed forces.

246

Text File Input

Member distributed torsions text Line 1: MEMBTORSION Next n Case,Mem,Sl,Un,St,Fi,Ts,Tf,Gen,MInc lines: Case Mem Sl Un St Fi Ts Tf Gen MInc

Load case number Member number Sub load number Units system (A/%) Start position Finish position Start torsion Finish torsion # of torsion loads to be generated Member # increment

(Integer) (Integer) (Integer) (1 Char) (Real) (Real) (Real) (Real) (Integer) (Integer)

Un choices are "A"=Actual, "%"=Percentage. See also Member distributed torsions.

247


Thermal loads text Line 1: THERMAL Next n Case,Elem,Type,Temp,GradY,GradZ,Gen,EInc lines: Case Elem Type Temp GradY GradZ Gen EInc

Load case number Element number Element type (M/P) Temperature change Reserved (must be set to 0.0) Plate thermal gradient # of thermal loads to be generated Element # increment

Type choices are "M"=Member, "P"=Plate. See also Thermal loads.

248

(Integer) (Integer) (1 Char) (Real) (Real) (Real) (Integer) (Integer)

Text File Input

Member prestress loads text Line 1: Next n lines:

PRESTRESS Case,Mem,Force,Gen,MInc

Case Mem Force Gen MInc

Load case number Member number Prestress force # of prestress loads to be generated Member # increment

(Integer) (Integer) (Real) (Integer) (Integer)

See also Member prestress.

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Plate pressure loads text Line 1: Next n lines:

PRESSURE Case,Plate,Px,Py,Pz,Gen,PInc

Case Plate Ax Px Py Pz Gen PInc

Load case number Plate number Axes system (L/G/A) X pressure Y pressure Z pressure # of loaded plates to be generated Plate number increment

(Integer) (Integer) (1 Char) (Real) (Real) (Real) (Integer) (Integer)

Ax choices are "L"=Local, "G"=Global-projected, "A"=Global-inclined. See also Plate pressure.

250

Text File Input

Self weight text Line 1: Next n lines:

SELFWEIGHT Case,Ax,Ay,Az

Case Ax Ay Az

Load case number X acceleration Y acceleration Z acceleration

(Integer) (Real) (Real) (Real)

See also Self weight.

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Combination load cases text Line 1: COMBINATIONS Next n lines: Comb,Case,Fact Comb Case Fact

Combination load case number Load case number (primary or combination) Multiplying factor

See also Combination load cases.

252

(Integer) (Integer) (Real)

Text File Input

Load case titles text Line 1: TITLES Next n lines: Case,Title,Notes Case Title Notes

Load case number Load case title Load case notes

(Integer) (50 Char) (255 Char)

See also Load case titles.

253


Lumped masses text Line 1: LUMPEDMASS Next n Case,Node,Tx,Ty,Tz,Rx,Ry,Rz,Gen,NInc lines: Case Node Tx Ty Tz Rx Ry Rz Gen NInc

Load case number Node number X translational mass Y translational mass Z translational mass X rotational mass Y rotational mass Z rotational mass # of loaded nodes to be generated Node number increment

See also Lumped masses.

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Text File Input

Spectral loads text Line 1: Next n lines:

SPECTRAL Case,Mode,Curve,MCase,Dx,Dy,Dz

Case Mode Curve MCase Dx Dy Dz

Load case number Mode shape Spectral curve name Mass case X direction vector Y direction vector Z direction vector

(Integer) (Integer) (50 Char) (Integer) (Real) (Real) (Real)

See also Spectral loads.

255


Steel member design text Line 1: STEELMEMBERS Next n lines: Group,Title,MList,SGrade,Units,LoadHeight, ScanCode,CalcLcMjr,LcMjr,BraceMjr,CalcLcMnr, LcMnr,BraceMnr, CalcLb,Lb+,Lb-,TopPos, TopRest,BotPos,BotRest, Ast,EndCon, EccEffect,Criteria,Bolts,Dia,Gen,GInc,MInc (Integer) (50 Char) List of analysis members in the group (50 Int) MList Strength grade (N/H) (1 Char) SGrade Units system (A/R) (1 Char) Units (1 Char) LoadHeight Load height position (C/T) (4 Char) ScanCode Library scan code (1 Char) CalcLcMjr Calculate LcMjr from a buckling analysis (Y/N) Major axis compression effective length (Real) LcMjr BraceMjr Major axis braced in position at both ends of group (Y/N) (1 Char) (1 Char) CalcLcMnr Calculate LcMnr from a buckling analysis (Y/N) Minor axis compression effective length (Real) LcMnr BraceMnr Minor axis braced in position at both ends of group (Y/N) (1 Char) Calculate Lb+ and Lb- (Y/N) (1 Char) CalcLb Positive bending effective length (Real) Lb+ Negative bending effective length (Real) LbList of restraint positions (intermediate only) on top flange (50 TopPos Real) List of restraint types (end and intermediate) on top flange (52 TopRest Char) List of restraint positions (intermediate only) on bottom (50 BotPos flange Real) List of restraint types (end and intermediate) on bottom (52 BotRest flange Char) Angle section type (A/S/L/X) (1 Char) Ast End connection type (C/F/W/S/L) (1 Char) EndCon (1 Char) EccEffect Consider eccentric effects (Y/N) Design criteria (W/D) (1 Char) Criteria Group Title

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Group number Group title

Text File Input Bolts Dia Gen GInc MInc

Maximum number of bolts in cross section (0=Welded) Bolt diameter Number of groups to be generated Group number increment Member number increment

(Integer) (Real) (Integer) (Integer) (Integer)

SGrade choices are "N"=Normal strength, "H"=High strength. Units choices are "A"=Actual, "R"=Ratio. LoadHeight choices are "C"=Shear centre or below, "T"=Top flange. CalcLcMjr choices are "Y"=Calculate LcMjr from a buckling analysis, "N"=Use the input value of LcMjr. BraceMjr choices are "Y"=Both ends of the design group are braced in position for buckling about the major axis, "N"=Either or both ends of the design group are not braced in position for buckling about the major axis. CalcLcMnr choices are "Y"=Calculate LcMnr from a buckling analysis, "N"=Use the input value of LcMnr. BraceMnr choices are "Y"=Both ends of the design group are braced in position for buckling about the minor axis, "N"=Either or both ends of the design group are not braced in position for buckling about the minor axis. CalcLb choices are "Y"=Calculate Lb+ and Lb- from the flange restraints, "N"=Use the input values of Lb+ and Lb-. TopPos and BotPos are lists of the intermediate flange restraint positions which can include @ multipliers but not dashes. For example, restraint positions 1.2,3.0,4.8,6.6,8.4,10.2,11.4 could be listed as 1.2,[email protected],[email protected] or 1.2,[email protected],11.4. TopRest and BotRest must be a string of characters without commas, dashes or @’s. For example FLLPLR. Ast choices are "A"=Single angle, "S"=Double angle with short legs connected, "L"=Double angle with long legs connected, "X"=Double starred angle. Ast is only considered if the section is an angle section.

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SPACE GASS 12 User Manual EndCon choices are "C"=Centroid, "F"=Flange, "W"=Web, "S"=Angle short leg, "L"=Angle long leg. EccEffect choices are "Y"=Consider end connection eccentric effects, "N"=Ignore eccentric effects. Criteria choices are "W"=Use weight design criteria, "D"=Use depth design criteria. See also Steel member design data.

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Text File Input

Terminator Line 1:

END

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Text file errors Error messages which may occur while a text file is being read by SPACE GASS are as follows. Illegal or missing numeric value Essential real or integer numeric value has been omitted or is beyond the problem size limits. Illegal data encountered Unexpected data type was encountered (eg. integer instead of real). Title line not recognised Incorrect data group title has been detected (eg. NEDES instead of NODES). Generation data out of limits Items to be generated would exceed the problem size limits. Change the generation data or choose "Problem size limits" from the Config menu and increase the limits. Illegal or missing character Illegal character detected or expected character not found. Maximum limit exceeded One of the problem size limits has been exceeded. Choose "Problem size limits" from the Config menu and increase the limits. Library not found The standard sections or materials library cannot be found. Wrong format library The standard sections or materials library is in an invalid or old format and cannot be read. Section or material not found Specified section or material name cannot be found in specified library. Demonstration version limit exceeded The demonstration version of the program allows only 1 section property, 1 material property, 5 steel design groups, and 1 steel design connection.

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Text File Input Not a valid SPACE GASS text file The file does not have a valid SPACE GASS text file format or the first line does not indicate that it is SPACE GASS data. Restraint positions are not in ascending order The intermediate flange restraint positions must be in ascending order. Restraint positions do not match types The number of intermediate flange restraint positions must match the number of restraint types less the two end restraint types. Each use of an @ multiplier in a restraint positions list must have only one corresponding restraint type. L or C restraint is ineffective A Lateral restraint type must have Full or Partial restraint types between it and the end of the design group on both sides to be effective. A Continuous restraint type must be between Full, Partial or Lateral restraint types to be effective. Ignored segments must be at ends You have specified an ignored segment at an intermediate position along the group. Segments to be ignored must be at either or both ends of the group only. Require intermediate restraint positions only Restraint positions should be specified for the intermediate restraints only. SPACE GASS already knows the positions of the restraints at the ends of the group. 100 members per design group limit exceeded A steel member design group cannot contain more than 100 members. 100 cases per combination limit exceeded A combination load case cannot contain more than 100 primary load cases. 100 flange restraints limit exceeded A steel member design group cannot contain more than 100 flange restraints per flange. No members in steel design group A steel member design group must consist of at least one analysis member. Restraint position exceeds maximum distance A flange restraint has been positioned beyond the length of the steel member design group.

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SPACE GASS 12 User Manual Illegal or missing restraint type An illegal character has been detected in the steel member design restraint types field or the restraint type is missing. Comma is missing A list of numbers is missing a comma. There must be a value between separators A list of values has two adjacent commas, dashes or @’s. Too many values in list A list of numbers contains too many values. Cannot use "-" range in this data field You are not permitted to use dashes in this list of integers. Cannot use "@" multiplier in this data field You are not permitted to use @’s in this list of numbers. Multiplier must be an integer The number before an @ in a list of numbers must be an integer. Cannot have a repeated member The same member has been referenced twice in a single connection. Must have at least one supported member All connection types require at least one supported member. An apex connection must be the same on both sides If you have specified one side of a connection to be an apex then you must use exactly the same connection type for the other side. An internal stiff seat must be the same on both sides If you have specified one side of a connection to be an internal stiff seat then you must use exactly the same connection type for the other side. This connection requires two supported members Apex and internal stiff seat connections require two supported members. This connection requires only one supported member Baseplate connections must have only one supported member. It doesn’t matter whether the supported member is specified as side A or side B.

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Text File Input

This connection requires a supporting member A supporting member is always required (except for apex, stiff seat or baseplate). This connection requires no supporting member Apex and baseplate connections cannot have a supporting member. No connection type specified You have not specified a valid connection type for one of the supported members. Supported member not specified You have not specified a supported member for one of the connection types. Invalid bolting procedure for connection type A snug bolting procedure cannot be used in bolted end plate, apex or moment baseplate connections, use bearing or friction bolting procedures. Haunches are only for B.E.P, welded moment or apex Haunches are supported only in bolted end plate, apex and welded moment connections. Invalid bolt strength for bolting procedure specified Normal strength bolts cannot be tensioned for bearing or friction bolting procedures. Use high strength bolts. Stiff seat bearing length required Because you have not specified a supporting member for the stiff seat connection, the bearing length cannot be calculated by SPACE GASS. Specify a supporting member or a stiff seat bearing length (or both). Cannot have fillet weld for welded apex connection Welded apex connections require butt welds for the flanges. Must have the same bolting procedure on each side You must specify the same bolting procedure on both sides of an apex or internal stiff seat connection. Cannot have a haunch on only one side of an apex If you have specified a haunch on one side of an apex connection then you must also specify a haunch on the other side. Must have the same haunch depth on each side of an apex

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SPACE GASS 12 User Manual Apex connections require the same haunch depth on both sides.

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Text File Input

Text file example The following sample text file contains all of the data for the worked example used in the appendices at the end of this manual. SPACE GASS Text File - Version 900 UNITS LENGTH:m, SECTION:m, STRENGTH:kPa, DENSITY:T/m^3, TEMP:Celsius, & FORCE:kN, MOMENT:kNm, MASS:T, ACC:m/sec^2, TRANS:m, STRESS:kPa HEADINGS "SPACE GASS Worked Example" "25m Single Span Portal Frame" "PS" "" NODES 1,0.000,0.000 2,0.000,3.750 3,0.000,7.500 4,1.630,7.585 5,3.260,7.671 6,6.250,7.828 7,12.500,8.155 8,18.750,7.828 9,21.740,7.671 10,23.370,7.585 11,25.000,7.500 12,25.000,3.750 13,25.000,0.000 MEMBERS 1,0.00,0, ,N,1, 2,1,1,FFFFFF,FFFFFF 2,0.00,0, ,N,2, 3,1,1,FFFFFF,FFFFFF 3,0.00,0, ,N,3, 4,3,1,FFFFFF,FFFFFF 4,0.00,0, ,N,4, 5,4,1,FFFFFF,FFFFFF 5,0.00,0, ,N,5, 6,2,1,FFFFFF,FFFFFF 6,0.00,0, ,N,6, 7,2,1,FFFFFF,FFFFFF 7,0.00,0, ,N,7, 8,2,1,FFFFFF,FFFFFF 8,0.00,0, ,N,8, 9,2,1,FFFFFF,FFFFFF 9,0.00,0, ,N,9,10,4,1,FFFFFF,FFFFFF 10,0.00,0, ,N,10,11,3,1,FFFFFF,FFFFFF 11,0.00,0, ,N,11,12,1,1,FFFFFF,FFFFFF 12,0.00,0, ,N,12,13,1,1,FFFFFF,FFFFFF RESTRAINTS 1,FFFFFR 2,RRFFFR,Y 13,FFFFFR SECTIONS 1,"530 UB 2,"360 UB 3,"360 UB 4,"360 UB

92","AUST250", ,"C1" 51","AUST250", ,"R1" 51-A","", ,"HNCH ",N,0.10773E-01,0.472E-06,0.14524E-04,0.63586E-03 51-B","", ,"S4 ",N,0.96446E-02,0.472E-06,0.14519E-04,0.36376E-03

MATERIALS 1,"STEEL","METRIC"

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NODELOADS 2,7,0.0,-4.5 MEMBFORCES 1,3,1,A,%,0.0,100.0,0.0,0.0,-0.9,-0.9 1,4,1,A,%,0.0,100.0,0.0,0.0,-0.9,-0.9 1,5,1,A,%,0.0,100.0,0.0,0.0,-0.9,-0.9 1,6,1,A,%,0.0,100.0,0.0,0.0,-0.9,-0.9 1,7,1,A,%,0.0,100.0,0.0,0.0,-0.9,-0.9 1,8,1,A,%,0.0,100.0,0.0,0.0,-0.9,-0.9 1,9,1,A,%,0.0,100.0,0.0,0.0,-0.9,-0.9 1,10,1,A,%,0.0,100.0,0.0,0.0,-0.9,-0.9 2,3,1,G,%,0.0,100.0,0.0,0.0,-2.250,-2.250 2,4,1,G,%,0.0,100.0,0.0,0.0,-2.250,-2.250 2,5,1,G,%,0.0,100.0,0.0,0.0,-2.250,-2.250 2,6,1,G,%,0.0,100.0,0.0,0.0,-2.250,-2.250 2,7,1,G,%,0.0,100.0,0.0,0.0,-2.250,-2.250 2,8,1,G,%,0.0,100.0,0.0,0.0,-2.250,-2.250 2,9,1,G,%,0.0,100.0,0.0,0.0,-2.250,-2.250 2,10,1,G,%,0.0,100.0,0.0,0.0,-2.250,-2.250 3,1,1,G,%,0.0,100.0,6.300,6.300,0.0,0.0 3,2,1,G,%,0.0,100.0,6.300,6.300,0.0,0.0 3,3,1,L,%,0.0,100.0,0.0,0.0,6.480,6.480 3,4,1,L,%,0.0,100.0,0.0,0.0,6.480,6.480 3,5,1,L,%,0.0,100.0,0.0,0.0,6.480,6.480 3,6,1,L,A,0.0,1.7410,0.0,0.0,6.480,6.480 3,6,2,L,A,1.7410,6.2590,0.0,0.0,3.600,3.600 3,7,1,L,A,0.0,3.4820,0.0,0.0,3.600,3.600 3,7,2,L,A,3.4820,6.2590,0.0,0.0,2.160,2.160 3,8,1,L,%,0.0,100.0,0.0,0.0,2.160,2.160 3,9,1,L,%,0.0,100.0,0.0,0.0,2.160,2.160 3,10,1,L,%,0.0,100.0,0.0,0.0,2.160,2.160 3,11,1,G,%,0.0,100.0,4.500,4.500,0.0,0.0 3,12,1,G,%,0.0,100.0,4.500,4.500,0.0,0.0 4,1,1,L,%,0.0,100.0,0.0,0.0,4.140,4.140 4,2,1,L,%,0.0,100.0,0.0,0.0,4.140,4.140 4,3,1,L,%,0.0,100.0,0.0,0.0,5.040,5.040 4,4,1,L,%,0.0,100.0,0.0,0.0,5.040,5.040 4,5,1,L,%,0.0,100.0,0.0,0.0,5.040,5.040 4,6,1,L,%,0.0,100.0,0.0,0.0,5.040,5.040 4,7,1,L,%,0.0,100.0,0.0,0.0,5.040,5.040 4,8,1,L,%,0.0,100.0,0.0,0.0,5.040,5.040 4,9,1,L,%,0.0,100.0,0.0,0.0,5.040,5.040 4,10,1,L,%,0.0,100.0,0.0,0.0,5.040,5.040 4,11,1,L,%,0.0,100.0,0.0,0.0,4.140,4.140 4,12,1,L,%,0.0,100.0,0.0,0.0,4.140,4.140 5,1,1,L,%,0.0,100.0,0.0,0.0,1.440,1.440 5,2,1,L,%,0.0,100.0,0.0,0.0,1.440,1.440 5,3,1,L,%,0.0,100.0,0.0,0.0,1.440,1.440 5,4,1,L,%,0.0,100.0,0.0,0.0,1.440,1.440 5,5,1,L,%,0.0,100.0,0.0,0.0,1.440,1.440 5,6,1,L,%,0.0,100.0,0.0,0.0,1.440,1.440 5,7,1,L,%,0.0,100.0,0.0,0.0,1.440,1.440 5,8,1,L,%,0.0,100.0,0.0,0.0,1.440,1.440 5,9,1,L,%,0.0,100.0,0.0,0.0,1.440,1.440 5,10,1,L,%,0.0,100.0,0.0,0.0,1.440,1.440 5,11,1,L,%,0.0,100.0,0.0,0.0,1.440,1.440 5,12,1,L,%,0.0,100.0,0.0,0.0,1.440,1.440 6,1,1,L,%,0.0,100.0,0.0,0.0,4.680,4.680 6,2,1,L,%,0.0,100.0,0.0,0.0,4.680,4.680 6,3,1,L,%,0.0,100.0,0.0,0.0,4.680,4.680

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Text File Input 6,4,1,L,%,0.0,100.0,0.0,0.0,4.680,4.680 6,5,1,L,%,0.0,100.0,0.0,0.0,4.680,4.680 6,6,1,L,%,0.0,100.0,0.0,0.0,4.680,4.680 6,7,1,L,%,0.0,100.0,0.0,0.0,4.680,4.680 6,8,1,L,%,0.0,100.0,0.0,0.0,4.680,4.680 6,9,1,L,%,0.0,100.0,0.0,0.0,4.680,4.680 6,10,1,L,%,0.0,100.0,0.0,0.0,4.680,4.680 6,11,1,L,%,0.0,100.0,0.0,0.0,4.680,4.680 6,12,1,L,%,0.0,100.0,0.0,0.0,4.680,4.680 7,1,1,L,%,0.0,100.0,0.0,0.0,0.9,0.9 7,2,1,L,%,0.0,100.0,0.0,0.0,0.9,0.9 7,3,1,L,%,0.0,100.0,0.0,0.0,0.9,0.9 7,4,1,L,%,0.0,100.0,0.0,0.0,0.9,0.9 7,5,1,L,%,0.0,100.0,0.0,0.0,0.9,0.9 7,6,1,L,%,0.0,100.0,0.0,0.0,0.9,0.9 7,7,1,L,%,0.0,100.0,0.0,0.0,0.9,0.9 7,8,1,L,%,0.0,100.0,0.0,0.0,0.9,0.9 7,9,1,L,%,0.0,100.0,0.0,0.0,0.9,0.9 7,10,1,L,%,0.0,100.0,0.0,0.0,0.9,0.9 7,11,1,L,%,0.0,100.0,0.0,0.0,0.9,0.9 7,12,1,L,%,0.0,100.0,0.0,0.0,0.9,0.9 SELFWEIGHT 1,0.0,-9.807E-03,0.0 COMBINATIONS 10,1,1.25 10,2,1.50 11,1,0.80 11,3,1.00 11,6,1.00 12,1,1.25 12,3,1.00 12,6,-0.96 13,1,0.80 13,4,1.00 13,7,1.00 14,1,1.25 14,5,1.00 14,7,-6.50 TITLES 1,Dead load (DL) 2,Live load including 4.5kN at ridge (LL) 3,Cross wind (CW) 4,Longitudinal wind at first internal frame (LW1) 5,Longitudinal wind with 0.2 external suction (LW2) 6,Cross wind internal pressure (IPCW) 7,Longitudinal wind internal pressure (IPLW) 10,1.25DL+1.5LL 11,0.8DL+CW+IPCW 12,1.25DL+CW+ISCW 13,0.8DL+LW1+IPLW 14,1.25DL+LW2+ISLW STEELMEMBERS 1,"","1,2",N,A,C,A ,N,20.0,1.7,Y,1.0,1.0, & "1.2,2.4,3.6,5.3,7",RLLLLFIF,"",RF,N,N,A,C,Y,W,0,0.02 2,"","5,6",N,A,C,A ,N,12.517,1.2,Y,1.0,1.0, & "1.3,2.5,3.7,4.9,6.1,7.3,8.1",RLLLLLLLF,"4.9",RLF,N,N,A,C,Y,W,0,0.02 3,"","8,7",N,A,C,A ,N,12.517,1.2,Y,1.0,1.0, & "1.3,2.5,3.7,4.9,6.1,7.3,8.1",RLLLLLLLF,"4.9",RLF,N,N,A,C,Y,W,0,0.02

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SPACE GASS 12 User Manual 4,"","12,11",N,A,C,A ,N,20.0,1.7,Y,1.0,1.0, & "1.2,2.4,3.6,5.3,7",RLLLLFIF,"",RF,N,N,A,C,Y,W,0,0.02 STEELCONNECT 1,"Left baseplate",0,1,0,8,0,S,S,0.0,0.0,0.0,0.0, & H,N,N,N,N,0.07,0.07,0.0,H,S,0,Y,Y,S,G,B,T 2,"Left eave",2,0,3,0,1,S,B,0.0,0.0,3.0,0.0, & H,N,N,N,N,0.07,0.07,0.0,H,S,0,Y,Y,S,G,B,T 6,"Bolted apex",0,6,7,2,2,B,B,0.0,0.0,0.0,0.0, & H,N,N,N,N,0.07,0.07,0.0,H,S,0,Y,Y,S,G,B,T 11,"Right eave",11,10,0,3,0,S,S,3.0,0.0,0.0,0.0, & H,N,N,N,N,0.07,0.07,0.0,H,S,0,Y,Y,S,G,B,T 12,"Right baseplate",0,0,12,0,8,S,S,0.0,0.0,0.0,0.0, & H,N,N,N,N,0.07,0.07,0.0,H,S,0,Y,Y,S,G,B,T END

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Structure Wizard Structure wizard You can open the structure wizard by clicking the "Structure wizard" from the Structure menu.


Structure wizard input provides a very fast means of inputting data into SPACE GASS for structures that conform generally to one of the standard structures shown above. The structure wizard input method can still be used for structures which don’t conform exactly to the structures shown above. In

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SPACE GASS 12 User Manual such cases it can be used to input the basic structure and then modified by one of the other data entry methods. For example, a portal frame with its apex off centre could be initially input as a symmetrical portal frame using the structure wizard and then modified graphically by moving the apex node to its correct location. Once a structure has been selected, a structure specific form is opened which allows you to input basic data relating to the frame geometry, supports, pattern loads, etc. SPACE GASS will then generate the structure, and apply any pattern loading, automatically. The input form for a single bay portal frame is shown below.

Important note regarding restraints applied to wizard generated models For all 2D frames generated by the structure wizard, out-of-plane translations on some non-support nodes are restrained. This has two major implications that you should be aware of. 1. If you extend the frame to 3D after it has been generated then the 2D restraints may no longer be appropriate. If this is the case, you should modify or delete them.

270

Structure Wizard 2. Even though a frame is 2D, it may often be appropriate to allow some nodes to move and/or rotate in the out-of-plane direction. This is especially the case if a buckling or dynamic frequency analysis is to be performed where out-of-plane movements can occur even when there are no loads in that direction. Because of this, you may have to modify the restraints generated by the structure wizard to allow these movements. Conversely, you may have to apply more out-of-plane restraints if those movements are prevented in your real structure. For more information, refer to Node restraint data and, in particular, the section entitled "Important note about restraining 2D frames".

271

Portal Frame Builder Portal frame builder This tool lets you generate all of the structural, load and design data for a complete portal frame building. You can then go ahead and analyse and design it using the normal analysis and design tools available in SPACE GASS. It supports gable (symmetrical and asymmetrical) and monoslope roofs, overhangs, knee braces, haunches, fly bracing, uneven frame spacings, openings, roof/wall bracing and end wall props. Wind loads are generated in accordance with AS/NZS 1170.2:2011 for all regions in Australia and New Zealand. They are calculated for each direction based on the region, average recurrence interval, terrain category (including transition zones), shielding and topography. Openings can be allowed for by specifying minimum and maximum internal Cp,i pressure coefficients for each wind direction. Wall loads can be applied to the columns (the normal situation) or to the eave ties and end frame rafters for buildings that have tilt-up panels. Load cases are automatically generated for all combinations of the dead, live and wind loads. You can access the portal frame builder tool from within the renderer by clicking the

button or by selecting "Portal frame builder" from the Structure menu.

Note that if you haven't purchased the portal frame builder tool, you can still run it in a free trial mode that limits you to a pre-defined building width and height, and prevents you from exporting or saving the job. All other features are fully activated. A video showing the portal frame builder in action can be viewed at www.spacegass.com/portal.

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Refer to Geometry, Extra data, Sections and materials, Loads, Load cases or Design for more details about the input parameters.

274


Portal frame geometry This form lets you define the basic geometric data for the portal frame building.

Options The basic options are largely self-explanatory, however some of the less obvious ones are explained in more detail below.

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SPACE GASS 12 User Manual If "Define eaves height by" is set to "Sheeting intersection" then the height is measured from the footing to the intersection point of the wall and roof sheeting. Otherwise it is measured to the "Springing height", which is the underside of the rafter (or haunch if one exists) at the face of the column. Eave and ridge ties are extended down the full length of the building, whereas end frame prop ties are placed just between the end frame and the first internal frame at each end of the building wherever there is a prop. Gridlines and dimensions can be generated automatically if ticked. You can also edit them or add extra dimensions manually using the renderer's normal gridline and dimensioning tools. If you tick "Align column outside flanges" and the end frame columns are different to the internal frames then the columns will be adjusted so that their outside flanges line up down the length of the building. If unticked, the columns will be aligned via their centroids. The "Connect rafter props to bottom flange" option lets you decide between connecting the props to the rafter centerline or to the bottom flange. If connected to the centerline the connection is pin-ended, whereas if connected to the bottom flange the connection is rigid. The reason for the rigid connection is to prevent shear force in the prop generating torsion in the rafter and potentially causing it to fail unrealistically. Geometry All dimensions in the geometry fields are relative to the sheeting lines.

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Portal Frame Builder Bay spacings and bracing The frames are assumed to be equally spaced by default, however you can change the spacings as required. The bay spacings are to the frame centroids and will affect the overall length of the building if you change them.

Purlin and girt details Purlins and girts are not added to the model as actual members, however they are included in the steel member design data as flange restraints. The purlin and girt depths are required so that the frame positions can be calculated relative to the sheeting lines. For gable frames, the purlins on each rafter are equally spaced with the first purlin positioned 200mm from the ridge. For monoslope frames, the purlins equally spaced and centered between the columns. The girts are equally spaced with the first girt positioned 200mm from the footing. Fly braces can be positioned at every 2nd, 3rd, etc... purlin or girt as specified by you. Of course you can manually adjust the purlin, girt and fly brace data to suit your exact requirements via the steel member design input data once the model has been generated.

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Portal frame extra data This form lets you input the end frame props, bracing, knee braces, haunches and the position of the model.

End frame props and bracing This table allows you to specify the props and bracing for the front and rear walls. If the front and rear walls have identical data then you can input the data for one wall and then click the "Duplicate at Front/Rear" button. Prop positions can be input as actual values or as percentages of the end frame width relative to the column centroids. Alternatively, you can click the "Generate End Frame Props" button to quickly generate equally spaced props with or without bracing.

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Knee braces and haunches You can specify knee braces or haunches in the internal and/or end frames using the following fields. The knee brace length is the horizontal distance from the face of the column, while its height is the vertical distance from the intersection of the centroids of the column and rafter. The haunch length is the horizontal distance from the face of the column.

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Positioning and numbering By default, the model is generated with its front-left corner at the global origin, however you can control this with the X,Y,Z position fields. This is especially useful if you are adding the generated model to an existing structure in your job. The nodes, members and load cases use the next available numbers unless you specify starting numbers in the "Start..." fields.

Connections The portal frame builder can also generate all of the main connections in the building. All you need to do is specify the type of connection to be used for the knees, ridges and baseplates. These can then be designed or checked in the steel connection design module.

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Portal frame sections and materials This form lets you define the section and material properties of the various components of the building.

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Portal frame loads This form lets you define the dead load, live load and wind load generation parameters.

Dead and live loads The "Roof sheeting and purlin dead load" is a permanent load that is applied to all load combinations, whereas the "Services and superimposed dead load" is considered to be a temporary load that is only applied to the downward load combinations. The dead loads you input are applied to the actual roof area, while the live load is applied to the plan projection of the roof area. If you tick the "Calculate" live load option then it will be calculated based on the maximum of 0.25 and 1.8/A + 0.12 kPa as given in AS/NZS 1170.1 table 3.2. Note that the distributed live load is applied to the entire roof area, even if the roof area is greater than 200m^2. The 1.4kN concentrated live load specified in AS/NZS 1170.1 (but not in conjunction with the distributed live load - see AS/NZS 1170.1 section 3.1) is not applied.

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Wind loads Wind loads can be calculated for any region in Australia or New Zealand. The average recurrence intervals (ARIs) for the ultimate and serviceability limit states are used to calculate the regional wind speeds from AS/NZS 1170.2 table 3.1.

Wind directions If you tick the "Apply same wind in all directions" option then you are only required to input one set of wind data for the shielding, topographic, terrain category and internal pressure parameters. Otherwise, these data must be defined for each of the four orthogonal building axes.

Shielding multiplier (Ms) The shielding multiplier (see AS/NZS 1170.2 section 4.3) takes into account shielding provided by other upwind buildings or structures. It is 1.0 if there is no shielding. You can enter the desired value directly or you can click the "Calculate" button and then input various shielding parameters and have Ms calculated for you. The ns, hs, bs and h values and the calculation of Ms are all explained in AS/NZS 1170.2 section 4.3.

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Topographic multiplier (Mt) The topographic multiplier (see AS/NZS 1170.2 section 4.4) takes into account the topography and its effect on the wind that is applied to the structure. It is 1.0 if there are no topographic effects. You can enter the desired value directly or you can click the "Calculate" button and then input various topographic parameters and have Mt calculated for you. The H, E, Lu, x and z values and the calculation of Mt are all explained in AS/NZS 1170.2 section 4.4.

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Terrain category The terrain category affects the terrain height multiplier Mz,cat (see AS/NZS 1170.2 section 4.2). Mz,cat can be based on a single terrain category or it can be an averaged value if the terrain category changes on the upwind side of the structure. SPACE GASS allows for averaging two terrain categories in accordance with AS/NZS 1170.2 section 4.2.3. Note that the "Approach" TC is closer to the structure than the "Upwind" TC and the "TC transition distance" is the distance from the structure to the point where the terrain category changes.

Internal pressure coefficients In order to take into account openings, you can input the Cp,i pressure coefficients for maximum pressure (Pos) and maximum suction (Neg). These coefficients are then used when factoring the Cp,i=1.0 internal pressure primary load cases into the ultimate and serviceability combination load cases.

Wind loads on walls Wind loads are normally applied to the columns when horizontal girts support the wall sheeting, however if the eave ties or end wall rafters are loaded instead (such

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Portal Frame Builder as with tilt-up panels) then you can tick the "Load rafters/eaves tie" options to allow for this.

Walls as effective surfaces When SPACE GASS calculates the action combination factors Kc,e and Kc,i (see AS/NZS 1170.2 section 5.4.3) it assumes that each wall is potentially an effective surface. You can, however, specify certain walls to be not considered as an effective surface in these calculations if required (see AS/NZS 1170.2 table 5.5).

Sheeting In order to calculate friction loads, the portal frame builder needs to know the type of sheeting and its direction. You can choose between "Smooth" (no friction loads), "Ribbed" or "Corrugated".

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Portal frame load cases This form lets you view the primary and combination load cases. The 4 internal wind pressure primary load cases (cases 4 to 7) are for the ultimate limit state and apply to a Cp,i pressure coefficient of 1.0. The 8 external wind pressure primary load cases (cases 8 to 15) are also for the ultimate limit state and are based on the actual Cp,e pressure coefficients. Along with dead load and live load, they are factored into the various combination load cases for ultimate and serviceability limit states. You can add extra combination load cases to this table, however it is sometimes easier to do this in the main SPACE GASS combination load cases datasheet once the model has been generated.

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Portal frame design This form lets you input the steel member design parameters. The data is the same as in the steel member design input form but with some fields disabled. For more information, refer to Steel member design data. Once the model has been generated, please check the steel member design data that was generated and check that it is what you want. If not, you can edit it using the normal steel member design data input/editing methods.

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Portal frame assumptions The following is a list of assumptions made in the current version of the portal frame builder. 1. Impact loading from wind borne debris (see AS/NZS 1170.2 section 2.5.8) is not taken into account. 2. The wind direction multiplier Md (see AS/NZS 1170.2 section 3.3) is assumed to be 0.95 for regions B, C and D, and 1.0 for all other regions and wind directions. 3. The permeable cladding reduction factor Kp (see AS/NZS 1170.2 section 5.4.5) is assumed to be 1.0. 4. Frictional drag forces (see AS/NZS 1170.2 section 5.5) are not taken into account. 5. The dynamic response factor Cdyn (see AS/NZS 1170.2 section 6) is assumed to be 1.0. 6. The wind load applied to the triangular part just below the roof in the end walls of gable buildings is not taken into account if there are no end wall rafter props. 7. The distributed live load is applied to the entire roof area, even if the roof area is greater than 200m^2. 8. The 1.4kN concentrated live load specified in AS/NZS 1170.1 (but not in conjunction with the distributed live load - see AS/NZS 1170.1 section 3.1) is not applied.

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Datasheet Input Datasheet input You can open a datasheet by clicking the toolbar button and then selecting from the datasheet menu that appears. Alternatively, you can select one of the datasheet items from the Structure, Loads or Design menus. Datasheet input is the one of the most useful methods of entering data into SPACE GASS. All types of frame and steel design data can be input or edited via a datasheet.

For more information about operating the datasheets, refer to Using datasheets.

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Using datasheets All datasheets have the same format, appearing in a grid format like a spreadsheet. The members datasheet is shown below.

Common datasheet operations Sorting the data on any column

Click the column heading to sort on. Further clicks cause the sorting to alternate between ascending and descending order.

Frozen key columns

Allows you to scroll the main data sideways without scrolling the key columns so that you can always see which row you are working on. In the members datasheet, the "Member" column is the key column.

Multi-row editing

Possibly one of the most useful datasheet editing tools! It

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Datasheet Input

allows you to edit multiple rows of data simultaneously. The procedure is as follows: 1. Select the rows to be edited by clicking the buttons at the left end of the rows, using the CTRL or SHIFT keys to highlight multiple rows (see "Selecting rows" below). 2. Move in any highlighted row to the column you want to edit. 3. Click the right mouse button. 4. Enter your data, select between replacing, multiplying, dividing, adding or subtracting and then click the Ok button. 5. All the highlighted rows will be updated. 6. Go back to step 2 above to edit another column.

Split screen

Move to the small black bar just to the left of the horizontal scroll arrow, click and drag it to the right to introduce and position a vertical split screen division.

Editing existing data

Move to the desired cell using the keyboard or mouse and then type in or select the desired data.

Entering new data

Move to the bottom (blank) row and then type in or select the desired data.

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Combo boxes

To edit combo box cells, either click the arrow and then make your selection or just use the keyboard arrow keys to move to the combo box cell and then type the first character of the desired selection. For example, to change a Yes/No combo box to Yes, just move to the cell and then type Y.

Selecting rows

Click the button to the left of the row to be selected. You can select multiple rows by: 1. Dragging up or down the selection buttons. 2. Selecting one row, holding down the CTRL key and then selecting additional rows. 3. Selecting one row, holding down the SHIFT key and then clicking on another selection button to select all the rows in between. Alternatively, you can click the blank button at the topleft corner of the datasheet to select all the rows.

Cutting, copying and pasting

Cut or copy selected rows from a datasheet to any other Windows program or paste from another Windows program into a datasheet.

Duplicating rows

Rows of data can be duplicated using the normal copy and paste methods, however some datasheets such as section properties contain hidden fields that would not be duplicated using these methods. For example, all the geometric data for shape builder sections is stored in hidden fields. To ensure that the hidden fields are duplicated the following procedure can be used: 1. Select the rows to be duplicated and then click the right mouse button on one of the buttons at the left end of the selected rows. 2. Select "Duplicate Rows" from the menu that appears. 3. Change the numbers of the duplicates via the "Paste Overwrite Error" form that appears so that

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Datasheet Input

the duplicates do not simply overwrite the selected rows. The duplicate rows will be inserted into the datasheet.

Deleting rows

Select the rows to be deleted and then press the Delete key or click the datasheet’s delete button or click the right mouse button and select Delete from the menu that appears.

Special buttons

Special buttons on some of the datasheets allow you to quickly change specific data in the current row. For example, the special fixity buttons in the members datasheet (shown left) let you choose commonly used fixity codes without having to type them in.

Counter

A counter at the bottom-right corner of the datasheet tells you how many rows of data are in the datasheet.

Generation

The generate button on some datasheets allows you to generate a number of extra items (members, nodes, etc.). When you click the generate button you will be presented with a generation form which varies for each type of input. Most of the generation forms are selfexplanatory, however some of them employ 2nd order generation which is explained below. Note that it is often better and more convenient to use the graphical Copy tool for generating data rather than using the datasheet generate buttons.

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SPACE GASS 12 User Manual Generation

The above node generation form allows you to generate items along two axes at once. It can also be used to generate extra series at different levels (ie. the 2nd order). Consider the following 20 node grid in the XY plane. It could have been created by inputting the coordinates for node 1 then generating four 1st order nodes (5,9,13 & 17) along a line with a node increment of 4 and X increment of 2.4, followed by three 2nd order rows of nodes with a node increment of 1 and a Y increment of 1.5.

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Grid of generated nodes

If only 1st order generation is required, you should specify zero for the number of 2nd order items to be generated. The node generation form also has the unique ability to generate nodes along a line, arc or helix. The axis of rotation, which only applies to an arc or helix, defines the point about which the nodes will be generated. The angle increment causes the nodes to be generated at some regular angle increment. The helix length increment defines a regular increment along a parametric path at which the nodes will be generated. 2nd order generation is also employed in the member and member concentrated load datasheets. Renumbering data Any data can be renumbered by simply changing its number in a datasheet. However, be careful, because related data in other datasheets will not be automatically renumbered to match. A better way to renumber nodes, members or plates is to use the graphics renumber tool. It not only lets you renumber large groups of nodes, members and plates effortlessly, it also adjusts all of the restraints, constraints, loads, and design data automatically to allow for the new numbering sequence (see also Renumber).

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A convenient way to quickly move around and edit numeric cells in a datasheet is to use the keyboard arrow keys to move to the desired cell, type the new data, then use the keyboard arrow keys to move to the next cell. You do not have to press ENTER to accept the new data. ! IMPORTANT NOTE ! When you use a datasheet to renumber items, none of the other data which may reference the renumbered items is adjusted. You must do this yourself or use the renumber tool instead (as explained above). See also Analysis data. See also Steel member design data. See also Steel connection design data.

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Graphical Input Graphical overview Inputting and editing your model using graphical methods is one of the most useful and intuitive input methods. You can see exactly what is in your model and you can see the changes as you make them. Nodes, members and plates can simply be drawn on the screen, and there are numerous tools for copying, renumbering, stretching, moving, generating loads and otherwise manipulating your model. When you start SPACE GASS, it opens the traditional graphics window which is the original graphical interface in SPACE GASS that has many tools for inputting, editing and displaying your model. There is also the renderer which is a more advanced graphical window that also lets you input, edit and display your model in both wireframe and fully rendered form. For more information about the use of the two graphical windows, refer to The renderer and The traditional graphics window. The renderer

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The traditional graphics window

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The renderer The SPACE GASS renderer is now the recommended tool for all of your input, analysis, design and display tools. Of course you can still edit your model in the traditional graphics window, however the editing tools in the renderer are generally more advanced and offer additional features over the traditional editing tools. All of the data is shared between the renderer and the traditional graphics window and so you can make changes in either one and then see your model updated in the other one as soon as it gets focus.

You can open the renderer by clicking the window.

button in the traditional graphics

Rendering mode When in the renderer you can switch between wireframe, outline and rendered views of your model by clicking the render mode selection button.

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Zoom, pan, rotate You can zoom, pan or rotate your model via the mouse scrollwheel or by dragging it around using the left or right mouse buttons as shown below.

Zoom by rotating the mousewheel or by holding down the mousewheel while moving the mouse or by pressing the keyboard Up/Down arrow keys. If you find that zooming doesn’t work, click on the graphics area before trying again. Pan by holding down the right mouse button while moving the mouse. Rotate by holding down the left mouse button while moving the mouse. You can also drag the view selector (shown below) or click on one of its faces, edges or corners.

The view selector An alternative to rotating the model by dragging it around directly is to drag the view selector around. You can also click one of the view selector faces, edges or

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Graphical Input corners to go straight to a specific viewpoint. If you click on the small square attached to the front face it will take you to the 30,10 viewpoint. Note that you can also right-click one of the view selector faces to change the working plane (or press X, Y or Z while you are working).

Node, member and plate property panels The property panels operate in two slightly different modes as described below. Mode 1 - When you double-click on a node, member or plate in the model, the appropriate property panel opens and you can make changes and then click the Ok button at the bottom of the panel to confirm the changes. Alternatively, if you make some changes in a property panel and then simply click on a another node, member or plate in your model, the previous changes will be confirmed and the newly selected item's data will appear in the property panel. Mode 2 - If you select one or more nodes, members or plates and then right-click and select "View/Edit Properties (Form)" from the menu that appears, the appropriate panel will open with the combined data for all of the selected items. When in this mode, you cannot select other nodes, members or plates until you have clicked the Ok or Cancel buttons at the bottom of the panel. Blank fields indicate that the data is different for the selected items. Be careful with blank fields because if you enter data into one of them then all of the selected items will get that data.

Single selection

Multiple selection

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SPACE GASS 12 User Manual Section and material property panels The section and material property panels are located by default on the right hand side of the renderer and are usually closed unless you have them pinned open. To open them simply hover over the tab.

You can open the property panels to view the section and material properties and color match them to the members in your model, or you can click a particular section or material in the panel to have all the matching members in your model selected.

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Graphical Input Controlling property panels Property panels can be pinned open by clicking the button at the top of the panel so that it changes to . If you click it again, it changes to , indicating that the panel is not pinned and will slide closed as soon as you move away from it. By dragging the title bar of a panel you can drag it away from the side of the renderer and place it anywhere on the screen or dock it to the left or right side of the renderer. You can also split the property panels into separate node, member and plate panels by dragging the relevant tab at the bottom of the panels.

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Graphical Input Drawing in the renderer Once you are in a tool that involves drawing a line or vector, to begin drawing you must position your cursor at the start of the line, click the left mouse button, move the cursor to the other end of the line and then click the left mouse button again. The line is dragged around with the cursor as you position the second point. The end of the first line then becomes the start of the next line and the process continues for subsequent lines until you press Esc or click the right mouse button (right-click) to end the sequence. There are a number of working plane, attachment, alignment and snap tools available to help you position points exactly where you want them while drawing or selecting points. These are explained as follows.

Working plane tool At any time while drawing lines or just generally moving the mouse cursor, you can see its coordinates displayed in the bottom right-hand corner of the renderer. Depending on the current working plane, you will notice that only two of the coordinates change as you move the mouse and the third one is held constant. You can change the working plane by pressing the X, Y or Z keys or by right-clicking one of the view selector faces or by clicking the working plane button bottom toolbar.

in the

Note that whenever you graphically select a point or a node, the working plane moves to the plane of that point or node. If you have a grid displayed (see below), it is drawn in the current working plane.

Attachment and alignment methods The following discussion applies to all tools that involve selecting points or drawing vectors, such as when drawing nodes, members or plates, moving, stretching, copying, extending, connecting or even when adding dimensions.

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SPACE GASS 12 User Manual During these operations there are a number of aligning, snapping and attachment tools that can help. To attach to a node (or the end of a member or the vertex of a plate), just move close to the node until it changes color. This indicates that you are close enough, and you can then click the left mouse button to attach to it. To attach to an intermediate point on a member, just move close to the member until it changes color. You can then move along the member to find its mid-point, third points, quarter points or fifth points, each of which will show up as a different colored dot with a label next to it. You can then click to attach to the desired point. Note that if you wish to position a point close to a node or member without attaching to it, you can hold down the C key to temporarily turn off the attachment feature.

If you are drawing the second end of a line then "Perpendicular" and "Orthogonal" attachment points will also be highlighted on the member if applicable.

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You can even align your point with an orthogonal line extending from a node or a member's midpoint. In order to do this you must first briefly hover over the node or member until you hear a faint pop sound that indicates that you have "locked on" to it. You can then move away and a dotted line will extend from the "locked on" node or member to your point, allowing you to line up with it exactly. Note that you can temporarily turn off alignment with locked on nodes or members by holding down the A key while you are working. You can also change the "locked on" delay via the "Lock delay" setting in the Attachment and alignment methods Preferences form in the Settings menu (see below).

Similarly, you can align your point with any of the "locked on" member's three local axes as shown below.

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When aligning with a locked on node or member, you can position your point an exact distance from the locked on item by simply typing the distance rather than having to click the point with your mouse.

When drawing a line, if it is close to being aligned with one of the three global axes then it will snap to that axis. You can then either click the point with your mouse or you can just type the length of your line.

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Snap tool The renderer also has a snap tool which can be turned on or off via the snap button in the bottom toolbar or by pressing the S key.

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SPACE GASS 12 User Manual Positioning points using the keyboard In addition to being able to type a length when you are locked on to an item or aligned with a global axis as described above, you can also type an X,Y,Z coordinate to position your point if you are not locked on to an item or aligned with an axis. Coordinates can be entered as absolute or relative and in cartesian or polar coordinates. Examples of each of these are as follows:

Type Alignment vector length Drawn line length Absolute cartesian Relative cartesian Absolute polar Relative polar

Situation Locked to a node or member Aligned with a global axis Not locked or aligned Not locked or aligned Not locked or aligned Not locked or aligned

Format Length

Example 10.2

Length

6.75

X,Y,Z

1.2,2.4,0.9

@X,Y,Z

@0,0,6.35

Length
6.5<45<0

@Length
For more information, refer to Using the keyboard to position points.

Selection methods You can select nodes, members or plates directly by clicking them with the left mouse button or you can use a selection window. If the second corner of the selection is to the right of the first then it is a "Normal" selection window in which only the nodes, members or plates that fall completely within the window are selected. Alternatively, if the second corner is to the left of the first then it is a "Crossing" selection window in which any nodes, members or plates that are within the window or which cross the boundary of the window are selected. A normal selection window is drawn as a rectangular box, whereas a crossing window is shown as a filled rectangle. The two types of selection window are shown below.

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In order to de-select nodes, members or plates, you can simply select them again, either by clicking directly or by using a selection window. Normal selection window

Crossing selection window

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Selecting a tool Once you have made your selection, you can get access to the various graphical tools by right-clicking and then selecting from the menu that appears. A typical member selection menu is shown below.

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After selecting from the menu, the tool you selected may open a form or it may require you to pick extra points. For example, if you selected the "Generate Arc" tool from the above menu, the Arc tool would then require you to pick a point on the concave side of the arc so that it knows which direction to use when creating the arc. Whenever the graphical editor requires you to do something, it displays a red prompt at the bottom-left corner of the window as shown below. It is therefore a good idea to look there if you are not sure what to do next.

Grid tool A grid can be displayed as a visual aid while you are developing or viewing your model. The grid also assists in identifying the working plane, as it is always displayed in that plane. The grid can be turned on or off via the grid button the bottom toolbar or by pressing the G key.

in

Note that if you change your working plane (see above) then the grid automatically moves to that new plane.

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Restraints Node restraints can be turned on or off in the renderer using the button in the bottom toolbar. Restraints are shown using combinations of the following icons. Icon

Restraint 3D fixed

Example FFFFFF

3D pinned

FFFRRR

2D fixed

FFRRRF

2D pinned

FFRRRR

1D translation fixed

RFRRRR

1D translation spring RSRRRR 1D rotation fixed

RRRRRF

1D rotation spring

RRRRRS

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SPACE GASS 12 User Manual Shortcuts While using any of the renderer tools, various keyboard shortcuts are available that can speed things up. They are listed below. Shortcut Tab key F11 key G key S key X, Y or Z keys A key (hold down) C key (hold down) Up/Down arrow keys Rotate mousewheel Drag with left mouse button Drag with right mouse button

Action Toggles all of the property panels on or off Toggles full screen mode on or off Toggles the grid on or off Toggles the snap on or off Allows you to set the working plane Temporarily disables aligning with a "locked on" node or member Temporarily disables attaching to a node or member Zooms in/out Zooms in/out Rotates Pans

Customizing toolbars All of the toolbars in the renderer can be hidden/shown, moved or undocked, and buttons can be added or deleted. For more information refer to Customizing Toolbars.

Renderer settings and preferences Various renderer settings and preferences are available from the Settings menu as shown below. In the following form:

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Graphical Input The "Alignment proximity" controls how close the mouse cursor must be to an axis aligned with a "locked on" node or member or a global axis in order to align with it. The "Cursor pickbox size" controls how close the mouse cursor must be to a node, member or plate in order to select it, lock onto it, or display its infotip. The "Lock delay" controls how long the mouse cursor must be near a node or member before you lock onto it.

In the following form: The "Use previous attributes..." option, if ticked, means that when you draw a new node, member or plate it will have the same properties (ie. section ID, material ID, etc) as the previous item you drew or selected. The "Allow duplicates..." option lets you draw members or plates on top of existing members or plates (ie. so that they share the same nodes). The "Allow hidden nodes to be selectable" option allows you to select nodes that you can't see due to being behind other objects. The "Curve quality" controls the smoothness of curved elements such as 3D nodes, members with circular cross sections, etc. A higher curve quality makes the renderer slightly slower and more memory hungry.

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SPACE GASS 12 User Manual The "Result quality" specifies how many short straight lines are used to approximate a curve when drawing deflected shapes, bending moment diagrams, etc. The "Highlight delay" controls how long the mouse cursor must be near a node, member or plate before it becomes highlighted. The "Infotip delay" controls how long the mouse cursor must be near a node, member or plate before its infotip appears. The "Maximum load cases shown together" is the maximum number of load cases that will be displayed simultaneously if you select "All load cases", "All primary load cases" or "All combination load cases". It is used to prevent memory overflow problems when many load cases are displayed together. Note that this setting is ignored if your model has less than 500 nodes. The "Rotation drag distance" is the number of pixels that you can move the mouse while the left button is held down before it will start to rotate the model. It is used to avoid the problem of the model rotating unintentionally when you are trying to select items or start a selection window. If this problem occurs then try increasing the rotation drag distance slightly. The "Rotation mode" controls how the model behaves when you rotate it with the mouse. Trackball mode lets the model rotate about all three axes, whereas Turntable mode prevents rotation about an axis normal to your computer screen. Trackball mode is a bit harder to control than Turntable.

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In the following form you can change the theme of the renderer via the "Skin" setting. This affects the colors and styles of all the forms, buttons and input fields. You can also separately change the colors of most the items in your model to suit your requirements.

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Other renderer tools Other features and tools currently available in the renderer are as follows:

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Graphical Input Printing of your rendered or wireframe model. Exporting to other image formats such as DWG, DXF, IGES or STL. Undo/redo with unlimited steps. Shape builder. Library editor. Find tool. Draw tool Copy node, member or plate properties tool. Move tool. Rotate tool. Copy tool. Mirror tool. Stretch tool. Scale tool. Renumber tool. Check connectivity tool. Generate arc tool. Generate bends tool. Subdivide tool. Intersect tool. Extend tool. Connect tool. Remove intermediate nodes tool. Remove crossed member nodes tool. Move intermediate nodes tool. Align members tool. Generate taper/haunch tool. Reverse member direction tool. Mesh plates tool. Reverse plate direction tool. Align plate axes tool. Copy node, member or plate loads tool. Generate moving loads tool Generate area loads tool. Combination load cases editor. Manage load cases tool. Static load to mass conversion tool. Load case titles viewer.

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If you have a large model with loads displayed and the renderer is operating slowly when you zoom, pan or rotate, try turning off the loads display or at least select less load cases to be displayed simultaneously.

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The traditional graphics window This is the original graphical interface for SPACE GASS that is gradually being replaced by The renderer.

The process of inputting a frame graphically into SPACE GASS simply involves drawing lines on the screen with your mouse. Each line represents a member or the edge of a plate. Nodes are automatically attached to the ends of each member, at plate vertices and at points where members intersect. Node, member and plate numbering is performed automatically, or at your discretion. The graphics renumber facility lets you renumber nodes and/or members, and automatically adjusts all the other data that references nodes and/or members accordingly. In order to draw a line, you must position your cursor at the start of the line, click the left mouse button, move the cursor to the other end of the line and then click the left mouse button again. The line is dragged around with the cursor as you position the second point. The end of the first line then becomes the start of the

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SPACE GASS 12 User Manual next line and the process continues for subsequent lines until you press ESC or click the right mouse button (right-click) to end the sequence. If the end of a member is drawn so that it touches another member, the two members become connected. If attach is on then you only have to position a member close to another member in order to connect them. If you connect a member to an intermediate point along an existing member, the existing member is subdivided into two, and a node is automatically inserted at the intersection point. Nodes, members and plates can be deleted, moved, copied, rotated, stretched, mirrored or subdivided. It is simply a matter of selecting a node, member or plate, or placing a window around a group of nodes, members and plates, and then performing the desired operation in accordance with the instructions following in this chapter. If you want to move a single node, you can just select it with your mouse and then drag it to its new location. You can see the members connected to the node being stretched as you move the node. You can select nodes, members or plates directly by clicking them with the left mouse button or you can use a selection window. If the second corner of the selection is to the right of the first then it is a "Normal" selection window in which only the nodes, members or plates that fall completely within the window are selected. Alternatively, if the second corner is to the left of the first then it is a "Crossing" selection window in which any nodes, members or plates that are within the window or which cross the boundary of the window are selected. A normal selection window is drawn with a solid line, whereas a crossing window is drawn with a dashed line. The two types of selection window are shown below. In order to de-select nodes, members or plates, you can simply select them again, either by clicking directly or by using a selection window. Normal selection window

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Once you have made your selection, you can get access to the various graphical tools by right-clicking and then selecting from the menu that appears. A typical member selection menu is shown below.

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After selecting from the menu, the tool you selected may open a form or it may require you to pick extra points. For example, if you selected the "Generate Arc" tool from the above menu, the Arc tool would then require you to pick a point on the concave side of the arc so that it knows which direction to use when creating the arc. Whenever the graphical editor requires you to do something, it displays a red prompt at the bottom-left corner of the window as shown below. It is therefore a good idea to look there if you are not sure what to do next.

Positioning points accurately in the traditional graphics window In order to input a structure graphically you have to be able to position the graphics cursor accurately. Unless you have the steady hands of a surgeon and you are an expert with the mouse, this is virtually impossible. Therefore, SPACE GASS has a number of indispensable tools that enable you to draw a structure to the nearest micron regardless of your surgical abilities. All of these tools can be accessed via the settings menu or activated, deactivated and/or configured using the graphics settings buttons across the bottom of the screen and/or the keyboard. All of these settings can be toggled without interrupting the use of most graphics tools. [Keyboard "G"] Clicking the Grid button displays a grid of dots on the screen at any user defined spacing. If the grid has been activated the grid button will appear depressed and instead of the text "Grid: Off" the button will display a message "Grid: x", where x is the spacing you defined. The grid can lie in the XY, XZ or YZ planes. See also Grid. [Keyboard "S"] The Snap facility, if turned on, activates a secondary crosshair graphics cursor which indicates the actual selection point and which moves in discrete steps rather than moving smoothly. The snap spacing can be set equal to the grid spacing or any other desired value. As with the Grid button, if you activate the Snap button and enter a spacing at the prompt the text on the button will change from "Snap: Off" to "Snap: x", where x is the spacing you defined.

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Graphical Input For example, if you set the snap spacing to 100mm the cursor will move in steps of 100mm, enabling you to draw to an accuracy of exactly 100mm. The button will indicate that snap has been set to 100mm by displaying the text "Snap: 100" (if units are set as mm). You can change the snap spacing as you move the cursor. SPACE GASS automatically senses when SNAP is not required and turns it off temporarily in such cases. See also Snap. [Keyboard "O"] The Ortho tool forces lines to be drawn either horizontally or vertically. Since structures are made up predominantly of horizontal beams and vertical columns, it is a very useful tool indeed. See also Ortho. [Keyboard "A"] The Attach facility displays an aperture circle with the graphics cursor and allows you to attach to existing members by simply picking points near them. The aperture circle indicates how close you must get to a member in order to attach to it. It is very useful for attaching new members to existing members or for locating points which are at the ends of members. See also Attach. [Keyboard "X,Y,Z and P"] The Plane facility allows you to change the current drawing plane. You will be able to select the drawing plane (choice of XY - "Z", YZ - "X" and XZ - "Y") as well as specifying an offset. An offset is the distance from a virtual plane to the specified plane, the distance being measured perpendicular to the virtual plane. For example, selecting the XY plane with an offset of 5m will result in every node being created with coordinates of x,y,5. See also Plane. [Keyboard "C"] The Coordinates facility allows you to toggle between one of four coordinate systems. The different systems available are:    

Cartesian Cartesian-Relative Polar Polar-Relative

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SPACE GASS 12 User Manual The text display at the bottom right corner of the screen will constantly change to reflect the position of the graphics cursor on the screen. The format of this text is governed by the coordinates system you have selected. Selecting the "Off" option switches all coordinates systems off and disables the coordinates display text. See also Coordinates. The keyboard can also be used to position points precisely. You simply type in the coordinates of the point using cartesian or polar coordinates in absolute or relative modes (depending upon the coordinates system selected). Note that there is no icon or button for this tool. You just need to type a number and the coordinates input form will appear automatically. See also Using the keyboard to position points. See also The renderer.

Other tools There are also a number of other tools that are of great use when inputting data graphically. The query frame facility (see also Node properties, Member properties and Plate properties) allows you to point to a node, member or plate and obtain information about node coordinates, member end fixities, section properties, material properties, etc. You can also query analysis results and steel member design results. You can use the zoom, pan and viewpoint facilities to view the structure in different ways. Zoom allows you to zoom in on a portion of the structure and have it enlarged for a detailed inspection. Pan allows you to translate the structure in any direction on the screen. Viewpoint allows you to rotate your viewpoint to any position around the structure. There are a host of additional tools which allow you to scale the structure or diagrams to any desired value, show the rendered model, superimpose loading diagrams, displacement diagrams, bending moment diagrams, shear force diagrams, axial force diagrams, torsion diagrams, reactions, stress diagrams, envelopes and dynamic mode shapes, display steel connection drawings, show local axes, restraints, constraints, offsets, top flanges, etc.

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Graphical Input You can also set up a number of filters, each of which limits the amount of the model that you can see and work on. The contents of each filter can be based on a range of axis coordinates, node properties, member properties, load types and many other selection criteria that you can control. Filters can also be selected in the output reports so that they can be quickly customized to include exactly what you want to see. Searching for specific nodes, members or plates is easy with the find function. You can search for nodes, members or plates directly, or by reference to their properties. All aspects of what you see on the graphics screen can be saved as views that can be named and then recalled at any time. All filters, viewpoint, scales, zoom, pan and other settings applicable at the time the view is saved are recalled when the saved view is recalled. Many of the above mentioned procedures are identical in the renderer, however some of them are not and some renderer tools have more options available. For more information, refer to The renderer.

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Selection methods This tool is replicated in the renderer and in the traditional graphics window. You can select nodes, members or plates directly by clicking them with the left mouse button or you can use a selection window. If the second corner of the selection is to the right of the first then it is a "Normal" selection window in which only the nodes, members or plates that fall completely within the window are selected. Alternatively, if the second corner is to the left of the first then it is a "Crossing" selection window in which any nodes, members or plates that are within the window or which cross the boundary of the window are selected. A normal selection window is drawn as a rectangular box, whereas a crossing window is shown as a filled rectangle. The two types of selection window are shown below. In order to de-select nodes, members or plates, you simply select them again, either by clicking directly or by using a selection window. Normal selection window


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Graphical Input

Note that you can select all nodes, members or plates by holding down Ctrl and pressing the A key.

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Select all This tool is replicated in the renderer and in the traditional graphics window. The Select All tool lets you quickly select all visible nodes, members or plates and then perform an operation on them. The procedure is as follows. 1. Click the right mouse button and then select "Select All" from the floating menu that appears. Alternatively, press Ctrl-A on the keyboard or select "Select All" from the Structure menu. The visible nodes, members or plates are highlighted graphically the same as if you had selected them by picking them with the mouse. Note that any nodes, members or plates outside the graphics window or those that are suppressed due to being filtered out are not selected.

2. You can then click on a toolbar button or click the right mouse button and choose from the floating menu that appears to perform an operation on the selected items. You can cancel the highlighting by pressing the keyboard ESC key or by selecting "Cancel" from the floating menu.

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Graphical Input

Attachment and alignment methods These tools are only available in the renderer. They include the functionality of the traditional Attach and Ortho tools. The following discussion applies to all tools that involve selecting points or drawing vectors, such as when drawing nodes, members or plates, moving, stretching, copying, extending, connecting or even when adding dimensions. During these operations there are a number of aligning, snapping and attachment tools that can help. To attach to a node (or the end of a member or the vertex of a plate), just move close to the node until it changes color. This indicates that you are close enough, and you can then click the left mouse button to attach to it. To attach to an intermediate point on a member, just move close to the member until it changes color. You can then move along the member to find its mid-point, third points, quarter points or fifth points, each of which will show up as a different colored dot with a label next to it. You can then click to attach to the desired point. Note that if you wish to position a point close to a node or member without attaching to it, you can hold down the C key to temporarily turn off the attachment feature.

If you are drawing the second end of a line then "Perpendicular" and "Orthogonal" attachment points will also be highlighted on the member if applicable.

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You can even align your point with an orthogonal line extending from a node or a member's midpoint. In order to do this you must first briefly hover over the node or member until you hear a faint pop sound that indicates that you have "locked on" to it. You can then move away and a dotted line will extend from the "locked on" node or member to your point, allowing you to line up with it exactly. Note that you can temporarily turn off alignment with locked on nodes or members by holding down the A key while you are working. You can also change the "locked on" delay via the "Lock delay" setting in the Attachment and alignment methods Preferences form in the renderer's Settings menu.

Similarly, you can align your point with any of the "locked on" member's three local axes as shown below.

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Graphical Input

When aligning with a locked on node or member, you can position your point an exact distance from the locked on item by simply typing the distance rather than having to click the point with your mouse.

When drawing a line, if it is close to being aligned with one of the three global axes then it will snap to that axis. You can then either click the point with your mouse or you can just type the length of your line.

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For information about the grid, snap and working plane tools in the renderer, refer to Grid, Snap and Plane. For more information about using the keyboard to position points, refer to Using the keyboard to position points. For more information about operating the other tools in the renderer, refer to The renderer.

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Graphical Input

Grid This tool is replicated in the renderer and in the traditional graphics window. A grid can be displayed as a visual aid while you are developing or viewing your model. The grid also assists in identifying the working plane, as it is always displayed in that plane. The renderer version The Grid tool can be turned on or off via the grid button or by pressing the G key.

in the bottom toolbar

Note that if you change your working plane then the grid automatically moves to that new plane.

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For more information about the attachment, alignment, snap and working plane tools in the renderer, refer to Attachment and alignment methods, Snap and Plane.

The traditional graphics window version You can display a rectangular grid in the XY, XZ or YZ global planes by clicking the toolbar or selecting "Grid" from the Settings menu or pressing "SHIFT+CTRL+G" on the keyboard (or just "G" if a graphics command is active). It is a useful visual reference as you move the cursor around the screen. The GRID can be set to any desired size provided it is not too fine or too coarse to be properly displayed. The GRID setting uses the same system of units as the structure being displayed. It can be toggled on or off by again clicking the "Grid" toolbar button or reselecting the "Grid" menu item. The current GRID setting is displayed on the graphics settings button (as indicated above).

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Graphical Input If you change the operating plane while a grid is displayed, the grid will not be updated until you perform an operation which refreshes the entire screen such as PAN, ZOOM, VIEWPOINT, SCALE, REDRAW, etc.

In the traditional graphics window, the grid can only be displayed in one of the global planes. It cannot be offset a distance out along one of the axes. If you are operating in a plane which is offset from the 0,0,0 global origin and your viewpoint is at an angle to the plane you are working in, do not try to use the displayed grid as a reference. It is only useful if you are operating in the same plane as the grid or if your viewpoint is perpendicular to the operating plane.

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Snap This tool is replicated in the renderer and in the traditional graphics window. The snap tool causes the cursor to move in discrete steps and allows you to accurately position points on an imaginary snap grid.

The renderer version The Snap tool which can be turned on or off via the snap button in the bottom toolbar or by pressing the S key. The snap spacing can be set to any desired increment or it can be made to match the currently displayed grid spacing.

For more information about the attachment, alignment, grid and working plane tools in the renderer, refer to Attachment and alignment methods, Grid and Plane.

The traditional graphics window version You can activate snap mode by clicking the toolbar or selecting "Snap" from the Settings menu or pressing "SHIFT+CTRL+S" on the keyboard (or just "S" if a graphics command is active).

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Graphical Input It allows you to accurately position the graphics cursor. The SNAP facility can be set to any desired increment which may or may not match the GRID setting (as desired). The SNAP increment uses the same system of units as the structure being displayed. It can be toggled on or off by again clicking the "Snap" toolbar button or reselecting the "Snap" menu item. The current SNAP setting is displayed on the graphics settings button (as indicated above).

For convenience, SNAP is automatically turned off temporarily during some graphics operations such as when you are simply picking members. This avoids the problem of not easily being able to pick objects due to the SNAP stepping effect.

When SNAP is turned off, you may notice that the graphics cursor moves in very small increments which are not useful fractions of whole numbers. These increments actually represent the distance between pixels on the screen. When you position the cursor on a known point, the coordinates display sometimes indicates that the cursor is not exactly on the point. This is because there is no pixel exactly on the point and the cursor has therefore moved to the closest pixel. SPACE GASS, however ignores the small movement to the closest pixel and assumes that the cursor is located exactly on the desired point. When SNAP is turned on this does not occur.

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Ortho This tool is only available in the traditional graphics window. The renderer has other alignment tools that replicate the function of this Ortho tool. The ortho tool limits the lines that you draw to only horizontal or vertical. You can activate ortho mode by clicking the toolbar or selecting "Ortho" from the Settings menu or pressing "SHIFT+CTRL+O" on the keyboard (or just "O" if a graphics command is active). If ORTHO is on, it activates a secondary crosshair graphics cursor which indicates the actual selection point and which moves in such a way that only horizontal or vertical lines (relative to the frame global axes) can be drawn. It is a very useful aid for drawing and positioning members, as most structures contain predominantly horizontal and vertical members. It can be toggled on or off by again clicking the "Ortho Mode" toolbar button or reselecting the "Ortho Mode" menu item. The current ORTHO setting is displayed on the graphics settings button (as indicated above).

If you are drawing new members with ORTHO on and ATTACH set to "NEAR/END", then the attachment point for any new member which attaches to an intermediate point on another member is positioned so that the new member stays truly orthogonal. You can also use ATTACH set to "ORTHOGONAL" for the same result.

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Attach This tool is only available in the traditional graphics window. The renderer has other attachment tools that replicate the function of this Attach tool. The attach tool lets you attach nodes, members, plates and reference points to existing nodes, members or plates without having to position the cursor exactly on them. You can change the attach setting by clicking on the toolbar button or selecting "Attach Mode" from the Settings menu or pressing "SHIFT+CTRL+A" on the keyboard (or just "A" if a graphics command is active). If ATTACH is on (as indicated on the toggle button above), the program displays an aperture circle with the graphics cursor and allows you to attach to existing nodes members when you pick points near them. The aperture circle indicates how close you must get to a node, member or plate in order to attach to it. The point of attachment depends on the ATTACH setting.

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The settings that may be displayed on the attach button are: Off: Middle/End: Nearest/End: n%/End: Middle: Nearest: Orthogonal: Perpendicular:

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Function is deactivated. Attaches to the middle or the end, whichever is closest. Attaches to the nearest point or, if an end falls within the aperture circle, attaches to the end. Attaches to a point at the nearest n% increment along the member, or the end, whichever is closest. Attaches to the middle. Attaches to the nearest point. Attaches to a point that makes the line being drawn exactly horizontal or vertical. Attaches to a point that makes the line being drawn perpendicular to the member being attached to.

Graphical Input

For example, if you draw a new member and wish to attach it to the end of an existing member, you can simply set ATTACH to "MIDDLE/END" and then locate the start of the new member near the end of the existing member. The two members will be automatically connected with a common node at the intersection point. To connect a member to the mid point of another member ensure that ATTACH is set to "MIDDLE" and then simply position the end of the first member to within the aperture circle radius of the second member. The second member is automatically broken into two and a node inserted at the intersection point.

The attach setting is only used if the aperture circle touches a node, member or plate.

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Plane This tool is replicated in the renderer and in the traditional graphics window. The plane tool allows you to specify an operating plane in or parallel to the global XY, XZ or YZ planes in which the graphics cursor will move. The renderer version At any time while drawing lines or just generally moving the mouse cursor, you can see its coordinates displayed in the bottom right-hand corner of the renderer. Depending on the current working plane, you will notice that only two of the coordinates change as you move the mouse and the third one is held constant. You can change the working plane by pressing the X, Y or Z keys or by right-clicking one of the view selector faces or by clicking the working plane button bottom toolbar.

in the

Note that whenever you graphically select a point or a node, the working plane moves to the plane of that point or node. If you have a grid displayed, it is drawn in the current working plane.

For more information about the attachment, alignment, grid and snap tools in the renderer, refer to Attachment and alignment methods, Grid and Snap.

The traditional graphics window version You can change the plane setting by clicking the toolbar button or selecting "Operating Plane" from the Settings menu or pressing "SHIFT+CTRL+P" on the keyboard (or "X", "Y", "Z" or "P" if a graphics command is active). It allows you to accurately move the graphics cursor to any desired position in 3D space.

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The current PLANE setting is displayed on the graphics settings button (as indicated above). The "Offset" field is the distance from the operating plane to the structure origin. It can be seen by observing the coordinates display as you move the graphics cursor. You can often take advantage of the fact that when picking points in any graphics operation, the operating plane offset is changed to match the coordinates of the most recently picked point. If you change the viewpoint such that the operating plane is no longer visible, the program will automatically change the operating plane to a visible one.

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Coordinates This tool is replicated in the renderer and in the traditional graphics window. The Coordinates tool shows the position of the mouse cursor while you are drawing lines or selecting points. The renderer version In the renderer, the coordinates tool is for display purposes only and cannot be changed to relative or polar. It appears in the bottom right-hand corner of the renderer as shown below.

The traditional graphics window version This tool not only allows you to view the mouse coordinates, but you can also cycle between cartesian and polar coordinates using absolute or relative modes.

You can change the displayed coordinates by clicking the toolbar button or selecting "Coordinates Display" from the Settings menu or pressing "SHIFT+CTRL+C" on the keyboard (or just "C" if a graphics command is active). The current COORDINATES setting is displayed on the graphics settings button (as indicated above). Choices are:

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Cartesian, Cartesian-Relative, Polar, Polar-Relative, Off.

Graphical Input When a graphics operation is active, the actual coordinates of the graphics cursor are displayed at the bottom-right corner of the screen. If you select the second corner of a window or line and the COORDINATES setting is in a relative mode then the coordinates displayed are relative to the first point of the window or line. Relative coordinates are the same as absolute coordinates when you select a single point or the start of a line.

The COORDINATES setting does not restrict your choice of Cartesian, polar, absolute and relative modes when inputting points from the keyboard. For example, you can enter a point from the keyboard using polar coordinates even if the COORDINATES display is set to Cartesian coordinates (see also Using the keyboard to position points).

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Using the keyboard to position points

If you can’t easily position a point using the mouse, you can simply type in the desired coordinates. You can enter points in cartesian or polar coordinates, using absolute or relative modes. As soon as you start typing, the following form will appear automatically.

A point can be entered using cartesian coordinates by simply typing the X, Y and Z values separated by commas. For example, 2.3,1.2,0.5 locates a point at X=2.3, Y=1.2 and Z=0.5. If you type less than three values for a point, the missing values are assumed to be zero. For example, 2.3,0,0 could be shortened to just "2.3", or 2.3,1.2,0 could be shortened to "2.3,1.2". To locate the "0,0,0" origin very quickly, you only have to type 0. A point can be entered using polar coordinates by typing a distance, followed by a vertical angle (from the global XZ plane), followed by a horizontal angle (from the global XY plane). <’s are used to separate the values rather than commas. For example, a point 10 units from the origin with a vertical angle of 45 and a horizontal angle of 15, could be typed in as 10<45<15. To enter points in relative mode (ie. relative to the other end of a line) apply an "@" prefix to the coordinates. For example, a point which is 8 units in the X direction and 6 units in the Y direction from a previous point, could be typed in as @8,6, or @10<36.9.

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Graphical Input If you are using the renderer, you can also type a length if you are drawing a line or vector that is aligned with a global axis or an alignment vector from a node or member that you are "locked on" to. Type Alignment vector length Drawn line length Absolute cartesian Relative cartesian Absolute polar Relative polar

Situation Locked to a node or member Aligned with a global axis Not locked or aligned Not locked or aligned Not locked or aligned Not locked or aligned

Format Length

Example 10.2

Length

6.75

X,Y,Z

1.2,2.4,0.9

@X,Y,Z

@0,0,6.35

Length
6.5<45<0

@Length
In the traditional graphics window, if you use the keyboard to type in coordinates for a point that is within the aperture circle distance of a member, and ATTACH is on, the point will not attach unless you make a direct hit. Any point positioned with the keyboard is kept at the exact coordinates that you type in. For information on attachment, alignment, working plane, grid and snap tools that allow you to position points accurately in the renderer, refer to Attachment and alignment, Plane, Grid, Snap and The renderer. For information on snapping and attachment tools available that allow you to position points accurately in the traditional graphics window, refer to The traditional graphics window.

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Infotips If you hover the mouse over a node, member or plate in the renderer, an infotip appears that gives useful information about the object as shown below. Infotips can be turned on or off by clicking the button in the bottom toolbar of the renderer. Note that you can also temporarily hide infotips while you're working by holding down the I key.

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Graphical Input

Property panels The property panels described here are only available in the renderer. Node, member and plate property panels The node, member and plate property panels operate in two slightly different modes as described below. Mode 1 - When you double-click on a node, member or plate in the model, the appropriate property panel opens and you can make changes and then click the Ok button at the bottom of the panel to confirm the changes. Alternatively, if you make some changes in a property panel and then simply click on a another node, member or plate in your model, the previous changes will be confirmed and the newly selected item's data will appear in the property panel. Mode 2 - If you select one or more nodes, members or plates and then right-click and select "View/Edit Properties" from the menu that appears, the appropriate panel will open with the combined data for all of the selected items. When in this mode, you cannot select other nodes, members or plates until you have clicked the Ok or Cancel buttons at the bottom of the panel. Blank fields indicate that the data is different for the selected items. Be careful with blank fields because if you enter data into one of them then all of the selected items will get that data. Note that after selecting nodes, members or plates, if the property panel is already open then the "View/Edit Properties" item will not appear in the right-click menu.

Single selection

Multiple selection

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Graphical Input Section and material property panels The section and material property panels are located by default on the right hand side of the renderer and are usually closed unless you have them pinned open. To open them simply hover over the tab.

You can open the property panels to view the section and material properties and color match them to the members in your model, or you can click a particular section or material in the panel to have all the matching members in your model selected.

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SPACE GASS 12 User Manual Controlling property panels Property panels can be pinned open by clicking the button at the top of the panel so that it changes to . If you click it again, it changes to , indicating that the panel is not pinned and will slide closed as soon as you move away from it. By dragging the title bar of a panel you can drag it away from the side of the renderer and place it anywhere on the screen or dock it to the left or right side of the renderer. You can also split the property panels into separate node, member and plate panels by dragging the relevant tab at the bottom of the panels.

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Multiple viewports This tool is only available in the traditional graphics window. SPACE GASS allows you to present more than one view of your structure on the screen at any one time in the traditional graphics window. Up to four different windows, or "viewports", can be displayed and individually configured to better display your structure. The procedure involves clicking the button or selecting "Viewports" from the Window menu. Once you have opened multiple viewports you can page through the different views using the and toolbar buttons (the TAB and SHIFT+TAB keys perform the same functions).

When you click the viewport tool you are presented with a number of different configurations. Most of these configurations are self explanatory, with the exception of the bottom four buttons. These four buttons allow you to select any one of the four viewports, either on their own, or in combination. Each corner of the screen corresponds with viewports 1, 2, 3 and 4 respectively. If one of the viewports selected is already displayed it will return to the configuration defined by the diagram on the button selected.

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Graphical Input Each of the viewports which are displayed have their own unique configuration. This applies to scales, viewpoint, filters, superimposed diagrams, toggle button settings, etc. The configuration you specify for a viewport will be retained when you close the viewport so that, when you open that viewport again, the same settings will be active. You can use the viewports to display a variety of different information including different views of the structure, graphics settings, bending moment, shear force, axial force, stress and displacement diagrams, dynamic and buckling mode shapes, filters, load cases, member top flanges, 3D geometry, local axes, etc. When you select a different viewport (either by clicking on it with the mouse, selecting it via the "Viewport" toolbar buttons or Window menu, or by using the TAB and SHIFT+TAB keys) the settings you have selected for that viewport will be indicated via the toggle buttons. Graphics commands apply to the active viewport. Some graphics commands allow you to move between viewports without exiting from the command. For instance, consider a job where you have 4 viewports displayed with viewport 1 as the active viewport. If you select the draw facility and start drawing a line in the active viewport, you can then move the cursor to any other viewport without exiting from the draw command. You will find that as you move the cursor between the viewports each viewport displays a drawn line which has the same coordinates as in the viewport where you first started drawing the line. This is useful in a number of situations, such as when you start drawing a line in one viewport but cannot locate the end point in that viewport. This feature applies to some graphics functions and can be switched on and off via the "Viewports" form (ie. by toggling the "Activate Viewport Under Cursor" check box in the viewports form).

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Node properties The node property forms described here are only available in the traditional graphics window. For information about the renderer's property panels, refer to Property panels or The renderer. Node properties include node coordinates, node restraints and master-slave constraints. Hence, selecting the graphical option for "Nodes", "Node restraints" or "Master-slave constraints" will all take you to the same node properties form. There are three modes available for editing node properties as follows. To edit or query node properties one node at a time Simply double-click on a node. Note "Edit/Query Node" in the title bar of the form that appears.

Although this mode only lets you edit the properties of one node at a time, you can simply click on any other node to display and edit its properties without exiting the command. When doing so, any changes you made to the properties of the previously displayed node are saved. You can also press the "Results" button and then click on any nodes to display their analysis results in a scrollable window (see also Query analysis results). To edit or query node properties for multiple nodes using a form Select some nodes graphically, click the right mouse button and then select "Properties (Form)" from the floating menu that appears.

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Graphical Input Note "Edit Node Properties" in the title bar of the form that appears.

Edit mode works in a similar way to edit/query mode except that you can’t select other nodes while the form is open. You can, however select multiple nodes initially and make changes to all of them simultaneously. Blank fields A blank field indicates that for the nodes selected, more than one value exists. If you leave such a field blank then the selected nodes will retain their individual values. However, if you type into a blank field then all of the selected nodes will receive the new value. Special buttons Shows or hides the master-slave constraints part of the node properties form.

Allows you to graphically select a master node rather than having to type in its node number. To edit or query node properties for multiple nodes using a datasheet Select some nodes graphically, click the right mouse button and then select "Properties (Datasheet)" from the floating menu that appears. Note that the datasheet that appears is different to the normal nodes datasheet because it contains extra columns for restraints and master-slave constraints.

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Refer to "Using datasheets" for information on how to operate the above datasheet.

You can view node restraints or master-slave constraints graphically by depressing the "View node restraints" or "View master-slave constraints" toggle buttons in the side toolbar.

If you change any node properties that affect the structure’s geometry, you may not be able to select some nodes, members or plates until after a redraw. This is due to their displayed position becoming out-of-date. The "Regen" check box allows you to order an automatic redraw after you exit the node properties form. You can remove restraints and/or constraints by either blanking the restraint or constraint field or by typing "NONE" in the field or by clicking the delete button. See also Nodes. See also Node restraints. See also Master-slave constraints. See also Floating mouse menus. See also View node / member / plate properties.

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Member properties The member property forms described here are only available in the traditional graphics window. For information about the renderer's property panels, refer to Property panels or The renderer. Member properties include member type, connectivity, orientation, fixity, section properties, material properties and member offsets. Hence, selecting the graphical option for "Members", "Section properties", "Material properties" or "Member offsets" will all take you to the same member properties form. There are three modes available for editing member properties as follows. To edit or query member properties one member at a time Simply double-click on a member. Note "Edit/Query Member" in the title bar of the form that appears.

Although this mode only lets you edit the properties of one member at a time, you can simply click on any other member to display and edit its properties without exiting the command. When doing so, any changes you made to the properties of the previously displayed member are saved.

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SPACE GASS 12 User Manual You can also press the "Results" button and then click on any members to display their analysis results in a scrollable window (see also Query analysis results). To edit or query member properties for multiple members using a form Select some members graphically, click the right mouse button and then select "Properties (Form)" from the floating menu that appears. Note "Edit Member Properties" in the title bar of the form that appears.

Edit mode works in a similar way to edit/query mode except that you can’t select other members while the form is open. You can, however select multiple members initially and make changes to all of them simultaneously. Blank fields A blank field indicates that for the members selected, more than one value exists. If you leave such a field blank then the selected members will retain their individual values. However, if you type into a blank field then all of the selected members will receive the new value. Special buttons Shows or hides the section properties part of the member properties form.

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Graphical Input Shows or hides the material properties part of the member properties form.

Shows or hides the member offsets part of the member properties form.

Allows you to input a section or material from a standard library.

Initiates the shape builder.

Initiates the standard shapes input. Section and material properties are different to the other items in the members form because a single section or material can be shared amongst many members. All other items of data in the members form have their own independent values for each member. Hence, as soon as you change the section or material property number, the rest of the section or material data changes to match. You can scroll through the sections or materials in the current job by changing the section or material number in the member properties form. All of the properties that have been defined for that section or material will be displayed. If no properties have been defined for that section or material then the name field will be blank, as will the properties fields. To edit or query member properties for multiple members using a datasheet Select some members graphically, click the right mouse button and then select "Properties (Datasheet)" from the floating menu that appears. Note that the datasheet that appears is different to the normal members datasheet because it contains extra columns for section properties, material properties and offsets.

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You can view member hinges, member offsets or section properties graphically by depressing the "View member hinges", "View member offsets" or "View rendered model" toggle buttons in the side toolbar.

If you change any member properties that affect the structure’s geometry, you may not be able to select some nodes or members until after a redraw. This is due to their displayed position becoming out-of-date. The "Regen" check box allows you to order an automatic redraw after you exit the node properties form. See also Members. See also Section properties. See also Material properties. See also Member offsets. See also Floating mouse menus. See also View node / member / plate properties.

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Plate properties The plate property forms described here are only available in the traditional graphics window. For information about the renderer's property panels, refer to Property panels or The renderer. Plate properties include plate type, connectivity, orientation of local axes, plate thickness, plate offset and material properties. There are three modes available for editing plate properties as follows. To edit or query plate properties one plate at a time Simply double-click on a plate. Note "Edit/Query Plate" in the title bar of the form that appears.

Although this mode only lets you edit the properties of one plate at a time, you can simply click on any other plate to display and edit its properties without exiting the command. When doing so, any changes you made to the properties of the previously displayed plate are saved. You can also press the "Results" button and then click on any plates to display their analysis results in a scrollable window (see also Query analysis results). To edit or query plate properties for multiple plates using a form Select some plates graphically, click the right mouse button and then select "Properties (Form)" from the floating menu that appears. Note "Edit Plate Properties" in the title bar of the form that appears.

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Edit mode works in a similar way to edit/query mode except that you can’t select other plates while the form is open. You can, however select multiple plates initially and make changes to all of them simultaneously. Blank fields A blank field indicates that for the plates selected, more than one value exists. If you leave such a field blank then the selected plates will retain their individual values. However, if you type into a blank field then all of the selected plates will receive the new value. Special buttons Allows you to input a material from a standard library. Material properties are different to the other items in the plates form because a single material can be shared amongst many plates. All other items of data in the plates form have their own independent values for each plate. Hence, as soon as you change the material property number, the rest of the material data changes to match. You can scroll through the materials in the current job by changing the material number in the plate properties form. All of the properties that have been defined for that material will be displayed. If no properties have been defined for that material then the name field will be blank, as will the properties fields. To edit or query plate properties for multiple plates using a datasheet Select some plates graphically, click the right mouse button and then select "Properties (Datasheet)" from the floating menu that appears.

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You can view plate offsets graphically by depressing the "View offsets" toggle button in the side toolbar.

If you change any plate properties that affect the structure’s geometry, you may not be able to select some nodes or plates until after a redraw. This is due to their displayed position becoming out-of-date. The "Regen" check box allows you to order an automatic redraw after you exit the node properties form. See also Plates. See also Material properties. See also Floating mouse menus. See also View node / member / plate properties.

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Node restraints Node restraints are incorporated into node properties. See also Property panels. See also Node restraints. See also Node properties.

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Section properties Section properties are incorporated into member properties. See also Property panels. See also Section properties. See also Member properties.

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Material properties Material properties are incorporated into the member and plate properties forms. See also Property panels. See also Material properties. See also Member properties. See also Plate properties.

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Master-slave constraints Master-slave constraints are incorporated into node properties. See also Property panels. See also Master-slave constraints. See also Node properties.

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Member offsets Member offsets are incorporated into member properties. See also Property panels. See also Member offsets. See also Member properties.

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Copy node properties This tool is replicated in the renderer and in the traditional graphics window. The Copy Node Properties tool lets you copy the restraint and master-slave constraint properties of a node to a selection of destination nodes. The renderer version After selecting the destination nodes, right-click and select "Copy Node Properties" from the menu that appears. You should then click the source node, after which its properties are copied to the destination nodes. The traditional graphics window version The procedure is the reverse of the renderer procedure above. After selecting the source node, right-click and select "Copy Node Properties" from the menu that appears. You should then select the destination nodes, right-click and then select Ok to have the properties copied.

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Copy member properties This tool is replicated in the renderer and in the traditional graphics window. The Copy Member Properties tool lets you copy the member, section, material and offset properties of a member to a selection of destination members. The renderer version After selecting the destination members, right-click and select "Copy Member Properties" from the menu that appears. You should then click the source member, after which its properties are copied to the destination members. The traditional graphics window version The procedure is the reverse of the renderer procedure above. After selecting the source member, right-click and select "Copy Member Properties" from the menu that appears. You should then select the destination members, right-click and then select Ok to have the properties copied.

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Copy plate properties This tool is replicated in the renderer and in the traditional graphics window. The Copy Plate Properties tool lets you copy the plate, material and offset properties of a plate to a selection of destination plates. The renderer version After selecting the destination plates, right-click and select "Copy Plate Properties" from the menu that appears. You should then click the source plate, after which its properties are copied to the destination plates. The traditional graphics window version The procedure is the reverse of the renderer procedure above. After selecting the source plate, right-click and select "Copy Plate Properties" from the menu that appears. You should then select the destination plates, right-click and then select Ok to have the properties copied.

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Draw This tool is replicated in the renderer and in the traditional graphics window. The Draw tool allows you to draw new nodes, members or plates and attach them to existing nodes, members or plates. Nodes are automatically generated at the ends of each member or plate vertex. If a member or plate is attached to the intermediate point of an existing member, the existing member is subdivided into two and a node is automatically inserted at the intersection point. When in drawing mode you can control the numbering of new nodes, members and plates being drawn by pressing the keyboard N, M or P keys and then specifying the number of the next node, member or plate to be drawn. Alternatively, you can simply let SPACE GASS find the next available node, member or plate. You can easily renumber any nodes, members or plates later using the Renumber tool. For members, the procedure is as follows. 1. Click the button.

(renderer) or

(traditional graphics window) toolbar

Note that you can switch to drawing plates by pressing the T key to switch to drawing triangular plates or the Q key to switch to drawing quadrilateral plates. You can switch back to drawing members by pressing the M key.

2. Pick the start of a new member. This can be a new point not connected to existing members or plates, or it can be an existing member or plate end point or member intermediate point. Don't forget that when drawing in the renderer, you can attach to other nodes or members, or you can "lock on" to a node or member and then align with an orthogonal line or an extension line from the "locked on" node or member. You can also align with one of the three global axes. For more information, refer to Attachment and alignment methods. Remember also that when drawing, you can use the mouse or you can simply type in the coordinates of the desired point(s). For more information, refer to

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Graphical Input "Using the keyboard to position points".

3. Pick the end of the new member. Again, this can be a new point or a point on an existing member or plate. 4. If you wish to draw another member that extends from the end of the member just drawn then pick another end point. You can keep picking end points for additional members. 5. Press ESC or the right mouse button to end the operation. 6. Return to step 1 above to draw another member, or press ESC or the right mouse button to exit from the tool.

Be careful when subdividing or connecting to intermediate points on members that have local Y or Z member offsets. Because local offsets are calculated relative to a straight line joining the member’s end nodes, they will change direction if you add intermediate nodes. It is therefore recommended that you should always convert any local Y or Z member offsets to global before adding intermediate nodes.

If you wish to draw multiple members between the same two nodes, you will need to first activate the "Allow duplicates when drawing new members" option in the "General configuration" item of the Config menu. For plates, the procedure is as follows. 1. Click the or (renderer) or (traditional graphics window) toolbar button and then select between drawing triangular or quadrilateral plates. Note that you can switch between drawing triangular or quadrilateral plates while drawing by pressing the T key to switch to drawing triangular plates or the Q key to switch to drawing quadrilateral plates. You can also switch to drawing members by pressing the M key. Note also that while in quadrilateral plate drawing mode, you can draw triangular plates by simply double-clicking the 4th node.

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2. Pick the start of a new plate. This can be a new point not connected to existing members or plates, or it can be an existing member or plate end point or member intermediate point. Don't forget that when drawing in the renderer, you can attach to other nodes or members, or you can "lock on" to a node or member and then align with an orthogonal line or an extension line from the "locked on" node or member. You can also align with one of the three global axes. For more information, refer to Attachment and alignment methods. Remember also that when drawing, you can use the mouse or you can simply type in the coordinates of the desired point(s). For more information, refer to "Using the keyboard to position points".

3. Pick the next vertex of the new plate. Again, this can be a new point or a point on an existing member or plate. 4. Pick the third and fourth (if a quadrilateral plate) vertices of the new plate. 5. If you wish to draw another plate that extends from the end of the plate just drawn then pick another point. You can keep picking points for additional plates. 6. Press ESC or the right mouse button to end the operation. 7. Return to step 1 above to draw another plate, or press ESC or the right mouse button to exit from the tool.

You can draw triangular plates while in quadrilateral plate drawing mode by double-clicking the 4th node of quadrilateral plates.

While drawing, you can switch between drawing members or plates by pressing the M key to switch to drawing members, the T key to switch to drawing triangular plates or the Q key to switch to drawing quadrilateral plates.

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Graphical Input

Plates must be flat (ie. all vertices in the same plane).

After drawing some members or plates, if you are not sure that they are properly connected to other nodes, members or plates, you can use the "Connectivity" tool.

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Move This tool is replicated in the renderer and in the traditional graphics window. The Move tool allows you to select one or more nodes, members or plates and move them in any direction on the screen. The renderer version After selecting the nodes, members or plates to be moved, right-click and select "Move" from the menu that appears. You should then pick two points that represent the ends of a vector through which the items are to be moved. Alternatively, if you have only selected one node to be moved, you can choose between "Move Along Vector" or "Move To Location". The "Move to Location" option requires you to pick a destination point rather than two ends of a vector. Don't forget that when drawing in the renderer, you can attach to other nodes or members, or you can "lock on" to a node or member and then align with an orthogonal line or an extension line from the "locked on" node or member. You can also align with one of the three global axes. For more information, refer to Attachment and alignment methods. Remember also that when drawing, you can use the mouse or you can simply type in the coordinates of the desired point(s). For more information, refer to "Using the keyboard to position points".

The traditional graphics window version There are two ways to move nodes. They are explained as follows. 1. For one node only: Click the toolbar button or select "Move" from the Structure menu and then select the node you wish to move. Move the node and pick its destination point. You can see the members attached to the node being moved and stretched as you move the node. OR For one or more nodes: Select the nodes you wish to move, click the right mouse button and then select "Move" from the floating menu that appears. Pick two points that

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Graphical Input represent the vector through which the selected nodes are to be moved. Remember that when picking points, you can use the mouse or you can simply type in the coordinates of the desired point(s). For more information, see "Using the keyboard to position points".

2. All selected nodes are then moved. 3. Select more nodes to move, or press ESC or the right mouse button to exit from the tool. To remove an intermediate node from two members connected end-to-end and convert them into a single continuous member, either use the Remove intermediate nodes tool in the renderer or use the Move tool to simply move the intermediate node onto either one of the end nodes.


After moving some nodes, if you are not sure that the members and plates attached to them are properly connected to other nodes, members or plates, you can use the "Connectivity" tool.

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Rotate This tool is replicated in the renderer and in the traditional graphics window. The Rotate tool allows you to select one or more nodes, members or plates and rotate them about any user defined axis. After selecting the nodes, members or plates to be rotated, right-click and select "Rotate" from the menu that appears. You should then pick the centre of rotation and then fill out the form that appears below. Note that the sign of the angle of rotation follows the "right hand screw rule".

Don't forget that when picking points in the renderer, you can attach to other nodes or members, or you can "lock on" to a node or member and then align with an orthogonal line or an extension line from the "locked on" node or member. For more information, refer to Attachment and alignment methods. Remember also that when drawing, you can use the mouse or you can simply type in the coordinates of the desired point(s). For more information, refer to "Using the keyboard to position points".

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Graphical Input

Copy This tool is replicated in the renderer and in the traditional graphics window. The Copy tool allows you to copy nodes, members or plates in any straight line direction, or around an arc or helix. This is very useful for structures such as trusses where you can draw just the first panel and then make copies of it to build up the complete structure. After selecting the nodes, members or plates to be copied, right-click and select "Copy Along Line", "Copy Along Arc" or "Copy Along Helix" from the menu that appears. If copying along a line, you should then pick two points that represent the ends of a vector through which the items are to be copied.

If copying along an arc, you should then pick the center of the arc and then fill out the form that appears below.

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If copying along a helix, you should then pick the center of the helix arc and then fill out the form that appears below.

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Graphical Input Don't forget that when drawing in the renderer, you can attach to other nodes or members, or you can "lock on" to a node or member and then align with an orthogonal line or an extension line from the "locked on" node or member. You can also align with one of the three global axes. For more information, refer to Attachment and alignment methods. Remember also that when drawing, you can use the mouse or you can simply type in the coordinates of the desired point(s). For more information, refer to "Using the keyboard to position points".

After copying some members or plates, if you are not sure that they are properly connected to other nodes, members or plates, you can use the "Connectivity" tool.

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Mirror This tool is replicated in the renderer and in the traditional graphics window. The Mirror tool allows you to create a mirror image of any user defined nodes, members or plates about any user defined surface. After selecting the nodes, members or plates to be mirrored, right-click and select "Mirror" from the menu that appears. You should then pick a point that lies anywhere in the mirror plane followed by filling out the form shown below.

Don't forget that when picking points in the renderer, you can attach to other nodes or members, or you can "lock on" to a node or member and then align with an orthogonal line or an extension line from the "locked on" node or member. For more information, refer to Attachment and alignment methods. Remember also that when drawing, you can use the mouse or you can simply type in the coordinates of the desired point(s). For more information, refer to "Using the keyboard to position points".

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Graphical Input

Delete This tool is replicated in the renderer and in the traditional graphics window. The Delete tool allows you to delete any or all of the structure. The items to be deleted are first highlighted so that you can verify them before they are actually removed. Nodes connected to deleted members or plates are also deleted unless they are connected to other members or plates that still exist. After selecting the nodes, members or plates to be deleted, press the Delete key or right-click and select "Delete" from the menu that appears. The selected items are then deleted. .

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Stretch This tool is replicated in the renderer and in the traditional graphics window. The Stretch tool lets you stretch all or part of your model. After selecting the nodes, members or plates to be stretched, right-click and select "Stretch" from the menu that appears. You should then pick an anchor point, plus two points that represent the ends of a vector through which the items are to be stretched. Each selected item is then moved parallel to the stretch vector by an amount that is proportional to its distance from the anchor point. The distance by which a point is moved parallel to the stretch vector is given by:

where D is the distance moved, Lv is the length of the stretch vector, Dn is the distance from the node to the anchor point in the direction of the stretch vector, and Dv is the distance from the start of the stretch vector to the anchor point in the direction of the stretch vector.

Don't forget that when drawing in the renderer, you can attach to other nodes or members, or you can "lock on" to a node or member and then align with an orthogonal line or an extension line from the "locked on" node or member. You can also align with one of the three global axes. For more information, refer to Attachment and alignment methods. Remember also that when drawing, you can use the mouse or you can simply type in the coordinates of the desired point(s). For more information, refer to "Using the keyboard to position points".

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Scale This tool is replicated in the renderer and in the traditional graphics window. You can use this tool to apply a scale factor to selected nodes, members or plates. For example, you could use it to enlarge your model by 20% or, if you had mistakenly input your node geometry in millimetre units instead of meters, you could scale the model down by 0.001. After selecting the nodes, members or plates to be scaled, right-click and select "Scale" from the menu that appears. You should then pick a base point about which the scaling occurs, followed by specifying the scale factor in the form shown below.

Don't forget that when picking points in the renderer, you can attach to other nodes or members, or you can "lock on" to a node or member and then align with an orthogonal line or an extension line from the "locked on" node or member. You can also align with one of the three global axes. For more information, see "Aligning, snapping and attachment tools" in The renderer. Remember also that when picking points, you can use the mouse or you can simply type in the coordinates of the desired point(s). For more information, see "Using the keyboard to position points".

The Scale tool only affects the node coordinates. It doesn’t adjust offsets, section properties, loads or any other parts of your model.

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Generate arc This tool is replicated in the renderer and in the traditional graphics window. The Arc generation tool lets you apply an arc to any member by adding intermediate nodes with any desired radius and arc plane. After selecting the members to be converted to an arc, right-click and select "Generate Arc" from the menu that appears. You should then pick any point on the concave side of the member so that the tool knows which way to bend the arc. If you have selected multiple members connected end-to-end and the "Generate continuous arc over multiple connected members" option is ticked then the Arc tool will try to generate a continuous arc that encompasses all of the connected members. This is particularly handy if you have already generated an arc and then wish to re-select it and change its radius. With this option unticked, a separate arc will be generated for each selected member.

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Graphical Input

Generate bends This tool in the renderer allows you to generate bends of any radius between members that are currently connected to each other.

After selecting the members to be adjusted, right-click and select "Generate Bends" from the menu that appears. Each bend is approximated by a series of straight line segments and you can specify the number of segments per 90 degrees in the form shown below. You can also specify a threshold angle to stop bends being generated between members that are close to being aligned in a straight line.

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Note that a bend will not be generated between connected members if the angle is less than the threshold angle, if the bend radius is too large or if there are more than two members or a plate connected to the intersection node.

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Subdivide This tool is replicated in the renderer and in the traditional graphics window. The Subdivide tool allows you to select one or more members and subdivide them by inserting intermediate nodes at regular or irregular positions along them. After selecting the members to be subdivided, right-click and select "Subdivide" from the menu that appears. You should then specify the number of subdivisions and their spacing in the form shown below. If the node insertion points are irregular, you can nominate "Insertion points" to be expressed as inclined distances, or as projected distances along one of the global axis directions. Naturally, you cannot nominate projected distances along a global axis which is at right angles to the axis of the member being subdivided. Insertion points are referenced from the node A end or Node B of the members. They can be expressed as actual distances or as percentages. For example, to subdivide a 10m beam into 2m, 3m, and 5m beams, you could type 2,5, or 2,50%, or 20%,50% into the "Insertion points" field. In all three cases, the final result is the same. If you are using percentages for all of the insertion points, then the inclined or projected axis specification is irrelevant.

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If the inserted nodes are to be equally spaced then you can leave the "Insertion points" field blank.


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Graphical Input

Mesh This tool is replicated in the renderer and in the traditional graphics window. The Mesh tool allows you to select one or more plates and then mesh them into smaller elements. You can also subdivide quadrilateral plates into triangles. Unlike frame elements, plate elements (like all finite elements) are not exact and hence the accuracy of the analysis increases as the number of plate elements is increased. It is therefore important that your model is properly meshed. The normal procedure for generating a well meshed model is to draw large plates that define the overall walls, slabs and other components and then use the mesh tool to subdivide the large plates into smaller elements. The meshing pattern also affects the analysis results to some extent. For example, because all of the elements in the following diagram are orientated at the same angle, an effect referred to as "mesh induced anisotropy" occurs which results in lower computational accuracy.

A meshing pattern that will achieve more accurate results is shown below.

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After selecting the plates to be meshed, right-click and select "Mesh Plates" from the menu that appears.

Note that if members also exist around the perimeter of the plates being meshed then they can also be subdivided during the meshing operation if the "Split

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Graphical Input members along plate edges and connect to newly generated intermediate nodes" option is checked.

After meshing, each plate element must be flat (ie. all vertices in the same plane), have internal angles less than 135 and an aspect ratio less than 4:1.

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Connect This tool is replicated in the renderer and in the traditional graphics window. The Connect tool allows you to connect members that cross each other within a specified distance but which are not currently connected. After selecting the members to be connected, right-click and select "Connect" from the menu that appears. Members that cross each other within the tolerance you specify in the following form will be connected.

After using the Connect tool, if you want to check that the members are properly connected, you can use the "Connectivity" tool. See also Intersect.

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Intersect This tool is replicated in the renderer and in the traditional graphics window. The Intersect tool allows you to join two or more members and automatically insert nodes at the intersection points. It works with members that are not touching each other, and with members that cross over each other. After selecting the members to be intersected, right-click and select "Intersect Move", "Intersect Extend" or "Intersect Offset" from the menu that appears. You should then click a member that the selected members are to intersect with. If you choose "Intersect Move", the ends of the selected members will be moved to the intersection points. If you choose "Intersect Extend", new members will be added that extend from the ends of the selected members to the intersection points. If you choose "Intersect Offset", member offsets will be added that offset the ends of the selected members to the intersection points. Because the "Move ends" or "Extend ends" selection only affects members which don’t already pass through the intersection point, the selection is irrelevant for members that cross over each other.

! IMPORTANT NOTE ! Concentrated loads and distributed forces acting on a member that is subdivided as the result of an intersect operation are now automatically re-distributed onto the subdivided members, however in the traditional graphics window distributed torsion, thermal and prestress loads are not!

Be careful when intersecting with members that have local Y or Z member offsets. Because local offsets are calculated relative to a straight line joining the member’s end nodes, they will change direction if you add intermediate nodes. It is therefore recommended that you should always convert any local Y or Z member offsets to global before intersecting at an intermediate point.

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After using the Intersect tool, if you want to check that the members are properly connected, you can use the "Connectivity" tool. See also Connect.

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Graphical Input

Extend Members can be extended or shortened using this tool in the renderer. After selecting the members to be extended or shortened, right-click and select "Extend" from the menu that appears. You must then select a reference point graphically. This just allows you to control which ends of the members will move and which ends will stay in place. The form shown below then appears. The "Mode" option lets you choose between specifying a new length or specifying an extension or reduction. The "Move" option lets you control which ends of the members will be moved. In the "New length" or "Extension" field at the bottom of the form, you can specify the new length or extension (or shortening) as an absolute value or as a percentage of the original member length.

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Remove intermediate nodes In the renderer you can remove intermediate nodes by selecting the desired members, right-clicking and then selecting "Remove Intermediate Nodes" from the menu that appears. Note that intermediate nodes can only be removed from members that are straight. For members that aren't straight you can simply use the Move tool to move an intermediate node onto its neighbour to remove it.

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Remove crossed member nodes This renderer tool lets you remove nodes that are at the intersection of members that cross over each other, such as you get with wall or roof cross bracing. After selecting the nodes attached to the crossed members, right-click and then select "Remove Crossed Member Nodes" from the menu that appears.

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Move intermediate nodes You can move intermediate nodes along a member using this tool in the renderer. After selecting the two members on either side of the intermediate node to be moved, right-click and select "Move Intermediate Nodes" from the menu that appears. In the form shown below, you can enter the distance to be moved or the new member lengths as absolute lengths or as percentages.

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Align members It is easy to align or stack members using the render's "Align Members" tool. After selecting the members to be adjusted, right-click and select "Align members" from the menu that appears and then click another member to align them with. In the form that appears you can then choose to align the members according to their tops, bottoms or sides. Alternatively, you can stack members side by side or on top of one another using the "Stack" options.

In the before and after diagrams below, the blue beam has been adjusted to align with the red beam's top flange.

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Generate taper/haunch The Taper/Haunch generation tool in the renderer lets you model tapered members with or without haunches. A member can be tapered by varying its depth, width or both depth and width. If the depth is varied, the taper can be applied to the top of the member, the bottom of the member, or evenly to both the top and bottom. If the width is varied, the taper is applied evenly to both sides of the member. If a haunch is selected, its depth is varied and is applied to the bottom of the haunch only. SPACE GASS uses a series of prismatic member segments to approximate the exact taper. You can use up to 50 segments per taper, however usually 3 segments is enough to get very close to the exact solution. The cross section dimensions for each prismatic member can be set equal to the taper’s largest end dimensions, smallest end dimensions or average dimensions for the segment under consideration. After selecting the member(s) to be tapered or haunched, right-click and select "Generate Taper/Haunch" from the menu that appears. If you have selected more than one member then they must be a continuous run of members with no gaps inbetween. Each selected member will become a segment of the total taper or haunch. Alternatively, if you have selected just one member then it will be subdivided as part of the taper/haunch process. The member that you select first determines the start of the taper/haunch. If there was only one member then the node A end will be the start of the taper/haunch. If you selected the members using a selection window or if you selected an intermediate member first, the start of the taper/haunch will be at the end with the lowest numbered member. The following form shows an example of generating a taper.

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The following form shows an example of generating a hanuch.

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Note that whenever a taper or haunch is generated, member offsets are also calculated and applied to the tapered/haunched members. The offsets take into account the changed centroid location in the built-up sections and ensure that the tapered/haunched members are correctly positioned relative to each other.

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Reverse member direction This tool in the renderer allows you to reverse the direction of selected members so that their local x-axes point in the opposite direction. It effectively swaps the node A and node B numbers in the member data. After selecting the members to be reversed, right-click and select "Reverse Member Direction" from the menu that appears to display the form as shown below. Any options that you tick in the form below will be adjusted so that they are not affected by the reversal, otherwise they will be reversed with the member.

Note that you can see the direction of members using the View member origins tool.

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Reverse plate direction This tool is replicated in the renderer and in the traditional graphics window. The Reverse Plate Direction tool lets you reverse the direction of plates, effectively swapping their front and back faces. It also results in the plate’s local x and z axes having their directions reversed.

Original Plate

Reversed Plate

After selecting the selected plates, right-click and select "Reverse Plate Direction" from the menu that appears. If you tick the "Adjust the direction of loads so that

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SPACE GASS 12 User Manual they are unaffected by the reversal" option then any plate loads will be adjusted so that they remain in the same general direction as before the plates were reversed. Note that the order of the nodes around a plate are changed after the plate has been reversed.

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Align plate axes This tool is replicated in the renderer and in the traditional graphics window. You can use this tool to align the local axes of a number of plates. After you have drawn and meshed some plates, you will probably find that their local axes are all pointing in different directions. If they are left this way then the results will be for different axis directions and they will be difficult to compare. It will also be difficult to produce meaningful contour diagrams if the plate axes are not aligned. After selecting the plates to be aligned, right-click and select "Align Plate Axes" from the menu that appears. You should then click a plate that the selected plates are to be aligned with. Options include allowing plates to be reversed (ie. the direction of their local zaxes are reversed), letting plates that are currently aligned with a direction node or axis to be re-aligned, and adjusting pressure or thermal gradient loads for reversed plates.

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Renumber This tool is replicated in the renderer and in the traditional graphics window. The Renumber tool allows you to renumber nodes, members or plates at any stage of the program operation. Items that reference nodes, members or plates such as restraints, constraints, loads and steel design data are automatically adjusted for the new numbering sequence. The renderer version After selecting the nodes, members or plates to be renumbered, right-click and select "Renumber" from the menu that appears. In the form shown below, the "Increment by" option allows you to create a gap in a sequence of nodes, members or plates without having to redefine the entire numbering sequence. You can also renumber in one, two or three directions simultaneously if required.

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The traditional graphics window version After selecting the nodes, members or plates to be renumbered, right-click and select "Renumber" from the menu that appears. In the form shown below, the "Increment by" option allows you to create a gap in a sequence of nodes, members or plates without having to redefine the entire numbering sequence.

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Note that if a node, member or plate is to be renumbered to a node, member or plate that already exists, SPACE GASS displays an error message and forces you to change the renumbering data before renumbering can proceed.

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Graphical Input

Connectivity check This tool is replicated in the renderer and in the traditional graphics window. The Connectivity tool lets you see graphically what is connected to a particular node, member or plate. It is a very handy tool if you are not sure if certain nodes. members or plates are properly connected. For example, it will quickly tell you if a member simply passes over a node or if it is properly connected to it. Right-click on a single node, member or plate and then select "Connectivity Check" from the menu that appears. The nodes, members and plates that are connected to the selected item are then highlighted graphically. You can then proceed to click on any other nodes, members or plates in your model to check their connectivity.

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Node loads This tool is only available in the traditional graphics window. This tool allows you to graphically apply force and moment loads to nodes. Node loads are always referenced to the global axes system. If you wish to apply node loads in local axes you should use member concentrated loads instead (see also Member concentrated loads). The procedure is as follows. 1. Select the nodes you wish to load, click the right mouse button and then select "Node Loads" from the floating menu that appears. OR Click the toolbar button or select "Node Loads - Graphical" from the Loads menu, select the nodes you wish to load, click the right mouse button and then click Ok.

2. In the load case form that appears, if you are inputting new loads then you would probably leave the load cases list field blank and specify the load cases in the datasheet that follows. If you are editing loads then you may also wish to leave the load cases list field blank unless there are a large number of load cases and you want to restrict the datasheet to just some of them. You should then choose between showing the loads applied to each selected node individually (ie. one line of data for each node) or applied as a group to all the selected nodes (ie. one line of data for all the nodes). The advantage of the "group" selection is that you only have to input one line of data in the datasheet to have it applied to all the selected nodes. This can be particularly useful if you are applying the same load to a number of nodes. If you are inputting a different load on each node then you should choose the "individual" selection. Choosing "individual" can also be useful if you are simply trying to see what loads are already applied to the nodes you have selected. If you have elected to show the loads applied to each node individually then you can also choose between showing all the selected nodes or just

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Graphical Input the ones that are loaded. If you are inputting new loads then you would probably choose to show all the selected nodes, whereas if you are editing existing loads or just viewing loads then showing just the loaded nodes may be preferable.

3. A datasheet then appears with any existing loads shown. You can add, edit or delete loads and then click the Ok button to save any changes. The operation of the datasheet is the same as the non-graphical datasheets (see also Datasheets).

Refer to "Using datasheets" for information on how to operate the above datasheet. See also Node load data.

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Prescribed node displacements This tool is only available in the traditional graphics window. This tool allows you to graphically specify displacements and rotations to nodes. The prescribed displacements are load case specific. Node displacements are always referenced to the global axes system and can only be applied to restrained degrees of freedom. The procedure is as follows. 1. Select the nodes you wish to displace, click the right mouse button and then select "Prescribed Node Displacements" from the floating menu that appears. OR Select "Prescribed Node Displacements - Graphical" from the Loads menu, select the nodes you wish to displace, click the right mouse button and then click Ok.

2. In the load case form that appears, if you are inputting new displacements then you would probably leave the load cases list field blank and specify the load cases in the datasheet that follows. If you are editing displacements then you may also wish to leave the load cases list field blank unless there are a large number of load cases and you want to restrict the datasheet to just some of them. You should then choose between showing the displacements applied to each selected node individually (ie. one line of data for each node) or applied as a group to all the selected nodes (ie. one line of data for all the nodes). The advantage of the "group" selection is that you only have to input one line of data in the datasheet to have it applied to all the selected nodes. This can be particularly useful if you are applying the same displacement to a number of nodes. If you are inputting a different displacement on each node then you should choose the "individual" selection. Choosing "individual" can also be useful if you are simply trying to see what displacements are already applied to the nodes you have selected.

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Graphical Input If you have elected to show the displacements applied to each node individually then you can also choose between showing all the selected nodes or just the ones that are displaced. If you are inputting new displacements then you would probably choose to show all the selected nodes, whereas if you are editing existing displacements or just viewing displacements then showing just the displaced nodes may be preferable.

3. A datasheet then appears with any existing displacements shown. You can add, edit or delete displacements and then click the Ok button to save any changes. The operation of the datasheet is the same as the non-graphical datasheets (see also Datasheets).

Refer to "Using datasheets" for information on how to operate the above datasheet. See also Prescribed node displacement data.

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Member concentrated loads This tool is only available in the traditional graphics window. This tool allows you to graphically apply force and moment concentrated loads to members. Member loads can be referenced to the global or local axes systems and can be positioned anywhere along the member. The procedure is as follows. 1. Select the members you wish to load, click the right mouse button and then select "Concentrated Loads" from the floating menu that appears. OR Click the toolbar button or select "Member Concentrated Loads Graphical" from the Loads menu, select the members you wish to load, click the right mouse button and then click Ok.

2. In the load case form that appears, if you are inputting new loads then you would probably leave the load cases list field blank and specify the load cases in the datasheet that follows. If you are editing loads then you may also wish to leave the load cases list field blank unless there are a large number of load cases and you want to restrict the datasheet to just some of them. You should then choose between showing the loads applied to each selected member individually (ie. one line of data for each member) or applied as a group to all the selected members (ie. one line of data for all the members). The advantage of the "group" selection is that you only have to input one line of data in the datasheet to have it applied to all the selected members. This can be particularly useful if you are applying the same load to a number of members. If you are inputting a different load on each member then you should choose the "individual" selection. Choosing "individual" can also be useful if you are simply trying to see what loads are already applied to the members you have selected. If you have elected to show the loads applied to each member individually then you can also choose between showing all the selected members or just

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Graphical Input the ones that are loaded. If you are inputting new loads then you would probably choose to show all the selected members, whereas if you are editing existing loads or just viewing loads then showing just the loaded members may be preferable.


Refer to "Using datasheets" for information on how to operate the above datasheet. You can apply more than one concentrated load to the same member within the same load case by specifying a different sub-load number for each different member concentrated load. See also Member concentrated load data.

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Member distributed forces This tool is only available in the traditional graphics window. This tool allows you to graphically apply distributed forces to members. Member loads can be referenced to the global or local axes systems and can be positioned to start and finish anywhere along the member. They can be uniformly distributed or linearly varying along the member. The procedure is as follows. 1. Select the members you wish to load, click the right mouse button and then select "Distributed Forces" from the floating menu that appears. OR Click the toolbar button or select "Member Distributed Forces Graphical" from the Loads menu, select the members you wish to load, click the right mouse button and then click Ok.


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Graphical Input the ones that are loaded. If you are inputting new loads then you would probably choose to show all the selected members, whereas if you are editing existing loads or just viewing loads then showing just the loaded members may be preferable.


Refer to "Using datasheets" for information on how to operate the above datasheet. You can apply more than one distributed force to the same member within the same load case by specifying a different sub-load number for each different member distributed force. This allows you to apply "stepped" distributed forces along a member without having to resort to intermediate nodes.

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SPACE GASS 12 User Manual See also Member distributed force data.

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Graphical Input

Member distributed torsions This tool is only available in the traditional graphics window. This tool allows you to graphically apply distributed torsions to members. Member distributed torsion loads are always referenced to the local axes system and can be positioned to start and finish anywhere along the member. They can be uniformly distributed or linearly varying along the member. The procedure is as follows. 1. Select the members you wish to load, click the right mouse button and then select "Distributed Torsions" from the floating menu that appears. OR Select "Member Distributed Torsions - Graphical" from the Loads menu, select the members you wish to load, click the right mouse button and then click Ok.


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SPACE GASS 12 User Manual the ones that are loaded. If you are inputting new loads then you would probably choose to show all the selected members, whereas if you are editing existing loads or just viewing loads then showing just the loaded members may be preferable.


Refer to "Using datasheets" for information on how to operate the above datasheet. You can apply more than one distributed torsion to the same member within the same load case by specifying a different sub-load number for each different member distributed torsion. This allows you to apply

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Graphical Input "stepped" distributed torsions along a member without having to resort to intermediate nodes. See also Member distributed torsion data.

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Thermal loads This tool is only available in the traditional graphics window. This tool allows you to graphically apply thermal loads to members or plates. The procedure is as follows. 1. Select the members or plates you wish to load, click the right mouse button and then select "Thermal Loads" from the floating menu that appears. OR Select "Thermal Loads - Graphical" from the Loads menu, select the members or plates you wish to load, click the right mouse button and then click Ok.

2. In the load case form that appears, if you are inputting new loads then you would probably leave the load cases list field blank and specify the load cases in the datasheet that follows. If you are editing loads then you may also wish to leave the load cases list field blank unless there are a large number of load cases and you want to restrict the datasheet to just some of them. You should then choose between showing the loads applied to each selected member or plate individually (ie. one line of data for each member or plate) or applied as a group to all the selected members or plates (ie. one line of data for all the members or plates). The advantage of the "group" selection is that you only have to input one line of data in the datasheet to have it applied to all the selected members or plates. This can be particularly useful if you are applying the same load to a number of members or plates. If you are inputting a different load on each member or plate then you should choose the "individual" selection. Choosing "individual" can also be useful if you are simply trying to see what loads are already applied to the members or plates you have selected. If you have elected to show the loads applied to each member or plate individually then you can also choose between showing all the selected members or plates, or just the ones that are loaded. If you are inputting new loads then you would probably choose to show all the selected members or

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Graphical Input plates, whereas if you are editing existing loads or just viewing loads then showing just the loaded members or plates may be preferable.


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Refer to "Using datasheets" for information on how to operate the above datasheet. See also Thermal load data.

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Member prestress loads This tool is only available in the traditional graphics window. This tool allows you to graphically apply prestress loads to members. The procedure is as follows. 1. Select the members you wish to load, click the right mouse button and then select "Prestress Loads" from the floating menu that appears. OR Select "Member Prestress Loads - Graphical" from the Loads menu, select the members you wish to load, click the right mouse button and then click Ok.

2. In the load case form that appears, if you are inputting new loads then you would probably leave the load cases list field blank and specify the load cases in the datasheet that follows. If you are editing loads then you may also wish to leave the load cases list field blank unless there are a large number of load cases and you want to restrict the datasheet to just some of them. You should then choose between showing the loads applied to each selected member individually (ie. one line of data for each member) or applied as a group to all the selected members (ie. one line of data for all the members). The advantage of the "group" selection is that you only have to input one line of data in the datasheet to have it applied to all the selected members. This can be particularly useful if you are applying the same load to a number of members. If you are inputting a different load on each member then you should choose the "individual" selection. Choosing "individual" can also be useful if you are simply trying to see what loads are already applied to the members you have selected. If you have elected to show the loads applied to each member individually then you can also choose between showing all the selected members or just the ones that are loaded. If you are inputting new loads then you would probably choose to show all the selected members, whereas if you are editing existing loads or just viewing loads then showing just the loaded

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SPACE GASS 12 User Manual members may be preferable.


Refer to "Using datasheets" for information on how to operate the above datasheet. See also Member prestress data.

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Plate pressure loads This tool is only available in the traditional graphics window. This tool allows you to graphically apply pressure loads to plates. Plate pressure loads can be referenced to the global or local axes systems. The procedure is as follows. 1. Select the plates you wish to load, click the right mouse button and then select "Pressure Loads" from the floating menu that appears. OR Click the toolbar button or select "Plate Pressure Loads - Graphical" from the Loads menu, select the plates you wish to load, click the right mouse button and then click Ok.

2. In the load case form that appears, if you are inputting new loads then you would probably leave the load cases list field blank and specify the load cases in the datasheet that follows. If you are editing loads then you may also wish to leave the load cases list field blank unless there are a large number of load cases and you want to restrict the datasheet to just some of them. You should then choose between showing the loads applied to each selected plate individually (ie. one line of data for each plate) or applied as a group to all the selected plates (ie. one line of data for all the plates). The advantage of the "group" selection is that you only have to input one line of data in the datasheet to have it applied to all the selected plates. This can be particularly useful if you are applying the same load to a number of plates. If you are inputting a different load on each plate then you should choose the "individual" selection. Choosing "individual" can also be useful if you are simply trying to see what loads are already applied to the plates you have selected. If you have elected to show the loads applied to each plate individually then you can also choose between showing all the selected plates or just the ones that are loaded. If you are inputting new loads then you would probably choose to show all the selected plates, whereas if you are editing

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SPACE GASS 12 User Manual existing loads or just viewing loads then showing just the loaded plates may be preferable.


Refer to "Using datasheets" for information on how to operate the above datasheet. See also Plate pressure data. See also Varying plate pressure loads.

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Graphical Input

Self weight This tool is only available in the traditional graphics window. Self weight or self mass can be input into any load cases by simply specifying the acceleration due to gravity in any of the three global axis directions. You can open the self weight datasheet by clicking the toolbar button or selecting "Self Weight" from the Loads menu and then entering data into the datasheet as explained in Self weight data.

See also Datasheet Input.

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Combination load cases This tool is replicated in the renderer and in the traditional graphics window. Combination load cases combine existing load cases to allow analysis of a structure with the interaction of different loads. Combination load cases are given a load case number the same as any other load case. The renderer version You can open the combination load cases grid by clicking the toolbar of the renderer as shown below.

button in the top

Existing combination load cases can be edited by typing into any cell. New combination load cases can be added by typing into the blank line near the top of the grid.

By hovering over a column heading or a cell in any row, information about the load case will be displayed including its title (if one exists).

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Graphical Input

Alternatively, if you right-click on a column heading or a cell in any row, you can input or edit a load case's title.

If you have a large number of columns and you don't want to repeatedly scroll sideways to get to the cells you need, you can condense the grid for any combination load case by simply clicking the arrow to the left of the combination load case you are interested in. You can then condense the grid for any other row or you can revert back to the default sorting by clicking the * button near the topleft corner of the grid.

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When creating combination load cases, if the columns you need are not included in the grid, you can add them by clicking the "Add Columns" button near the top-right corner of the grid and then listing the extra load cases required.

The traditional graphics window version You can open the combination load cases datasheet by clicking the button as shown below.

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toolbar

Graphical Input

See also Datasheet Input.

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Load case titles This tool is only available in the traditional graphics window. Load case titles allow you to describe your load cases so that they can be easily identified. For each load case you can specify a short title and a longer description. You can open the load case titles datasheet by selecting "Load Case Titles" from the Loads menu and then entering data into the datasheet as explained in Load case title data.

Note that you can open a load case titles viewer from within the renderer that can be left open while you work with other tools. For more information, refer to Load case titles viewer. See also Datasheet Input.

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Graphical Input

Lumped masses This tool is only available in the traditional graphics window. This tool allows you to graphically apply lumped masses to nodes. Masses are always referenced to the global axes system. You must apply some lumped masses before a dynamic frequency analysis can be performed. The procedure is as follows. 1. Select the nodes you wish to load, click the right mouse button and then select "Lumped Masses" from the floating menu that appears. OR Click the toolbar button or select "Lumped Masses - Graphical" from the Loads menu, select the nodes you wish to load, click the right mouse button and then click Ok.

2. In the load case form that appears, if you are inputting new masses then you would probably leave the load cases list field blank and specify the load cases in the datasheet that follows. If you are editing masses then you may also wish to leave the load cases list field blank unless there are a large number of load cases and you want to restrict the datasheet to just some of them. You should then choose between showing the masses applied to each selected node individually (ie. one line of data for each node) or applied as a group to all the selected nodes (ie. one line of data for all the nodes). The advantage of the "group" selection is that you only have to input one line of data in the datasheet to have it applied to all the selected nodes. This can be particularly useful if you are applying the same mass to a number of nodes. If you are inputting a different mass on each node then you should choose the "individual" selection. Choosing "individual" can also be useful if you are simply trying to see what masses are already applied to the nodes you have selected. If you have elected to show the masses applied to each node individually then you can also choose between showing all the selected nodes or just the ones that are loaded. If you are inputting new masses then you would

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SPACE GASS 12 User Manual probably choose to show all the selected nodes, whereas if you are editing existing masses or just viewing masses then showing just the loaded nodes may be preferable.

3. A datasheet then appears with any existing masses shown. You can add, edit or delete masses and then click the Ok button to save any changes. The operation of the datasheet is the same as the non-graphical datasheets (see also Datasheets).

Refer to "Using datasheets" for information on how to operate the above datasheet. Note that static loads can be converted to masses using the static load to mass conversion tool in the renderer. For more information, refer to Static load to mass conversion. See also Lumped mass data.

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Graphical Input

Static load to mass conversion Static loads such as dead loads and live loads can be converted to masses if you want to use them in a dynamic analysis and you don't want to re-enter them from scratch as masses. You can select the "Static Load to Mass Conversion" option from the Loads menu in the renderer to bring up the form below. You can convert a number of static load cases at once by entering them as a list in the "Static load case list" field. You must also enter a corresponding list of mass load cases in the "Mass case list" field. They can have the same load case numbers as the static loads, however for your own organizational purposes it is usually a good idea to keep them separate. It is usual to have the "Create mass in all three directions regardless of static load direction" option ticked, as masses generally have inertia in all three directions. As such, static loads that have components in more than one direction on a single object are first resolved into the resultant direction and then converted to a single mass. Alternatively, if the "Create mass in all three directions..." option is not ticked then the masses will simply be placed in the same directions as their source static loads. If the "Delete masses in destination mass cases first" option is ticked then all masses in the destination mass cases will be deleted first, otherwise they will be added to.

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Note that self weight static loads are not converted with this tool because self mass can be generated automatically in the dynamic analysis. Note also that moments and torsions are not converted to rotational masses.

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Spectral loads This tool is only available in the traditional graphics window. Spectral loads must be defined for each load case that you wish to include in a dynamic response analysis. You can open the spectral loads datasheet by selecting "Spectral Load Data" from the Loads menu and then entering data into the datasheet as explained in Spectral load data.

Note that spectral curves can be created, imported or exported via the spectral curve editor. For more information, refer to Spectral curve editor. See also Datasheet Input.

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Area loads One-way or two-way area loads can be generated by specifying a pressure that is applied to a roof or a floor or any other set of members that can form closed or open polygons. The pressure loads are converted to member distributed forces calculated from the contributing area of each member. You can select many members that form multiple open or closed areas and the area loading tool will process them all at once.

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Graphical Input

Two-way loads require closed areas formed by three or more perimeter members and the generated member loads are based on the load surface spanning in two directions, generally resulting in a mixture of uniform, triangular and trapezoidal loads. One-way loads don't require closed areas and the generated loads are based on the load surface spanning in just one direction, resulting in uniformly distributed loads if the supporting members are parallel, or trapezoidal if the supporting members are not parallel. After selecting the desired members to be loaded, right-click and then select "Generate Area Loads" from the menu that appears.

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For one-way area loads, if you click the "View Dummy Members" button in the one-way area loading form shown below, you can visually see the dummy members that effectively "close" the open polygons on which the one-way loads are based. Of course, the "dummy" members don't exist and don't attract any load. "Projected" areas results in the loads being based on the projected areas normal to the load direction, whereas "Actual" areas cause the generated loads to be based on the actual areas regardless of the load direction. The load direction can be parallel to one of the global axes or along any vector that you specify. You can select the load direction vector graphically by clicking the "Select Vector" button. If the "Generate loads normal to area in general load direction" option is ticked then the pressure is applied in the general load direction that you have specified, but normal to each polygon. This is handy if you have a pitched roof and you want to apply a generally vertical wind load that is normal to the roof on both sides of the ridge.

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The "Generate uniformly distributed forces only" option forces the pressure applied to a polygon to be applied uniformly to each perimeter member rather than as triangular or trapezoidal loads.

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Sea Loads This tool lets you generate wave, ocean current, marine growth and buoyancy loads on submerged structures in marine and offshore environments where these effects impose significant loading on the affected structure. The procedure for load calculation starts with the analysis of the wave by an appropriate theory to determine the water particle velocities and accelerations at various depths in the water body. The computed velocities and accelerations are combined with any additional water current velocities (tidal, density current, storm velocity, etc), marine growth loads and buoyancy loads for determining the effective loading on individual structural elements. When combining wave and water currents the Doppler effect of the current on the wave is automatically taken into account. Presently, Airy's linear wave theory and Stokes' 5th and 2nd order non-linear wave theories are incorporated into this tool. Sea loads on the structure comprising drag and inertia loading on individual structural members are computed using Morison's equation. The formulation applies strictly to skeletal framed structures with slender tubular members, but can also be applied to framed structures with non-tubular members applying modified coefficients for drag and inertia. The tool is not suitable for the computation of sea loads on large bodies such as vessels, shipshaped or boxed and/or plate structures where the length to effective diameter ratio of any individual element is small. The sea load generator uses the concept of "scenarios", each of which represents the motion of a wave and generates multiple load cases that correspond with the various positions of the wave. It is normal for a scenario to represent a full wavelength, however you can reduce it to part of a wavelength by changing the "Phase increment" and "Steps" variables so that their product is less than 360 degrees if desired. The procedure is as follows: 1.

From within the renderer, select the members that are flooded, click the right mouse button and then select "Generate Sea Loads" from the floating menu that appears. Note that all of the submerged members in your model will be loaded, regardless of whether you select them or not. The members you select will indicate which of them are to be regarded as "flooded". The unselected (non-flooded) members will

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SPACE GASS 12 User Manual be subjected to buoyancy loads if they are tubular, whereas the selected (flooded) members will not.

2.

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In the sea load form that appears (as follows), change the data to suit your requirements and then click the Ok button.

Graphical Input General Parameters:

The following parameters are general in nature and apply to all the sea load cases. Water depth This is the depth of water above the mudline (or seabed). Mudline level The mudline level is essentially the seabed level. It is the level relative to the global origin of the SPACE GASS model and is negative if the mudline is below the SPACE GASS origin (the normal situation). It may be prudent to set up your model so that its origin is at the waterline and therefore Mudline level = - (Water depth). This also means that any "Levels" such as the mudline level, marine growth levels or ocean current levels would always be negative if below the waterline. Water density The normal density of water. Kinematic viscosity This varies with the water temperature. The default value is based on a water temperature of 15 deg C.

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Surface roughness The surface roughness affects the drag of the water on the structure. The surface roughness value you specify is only used on surfaces that have no marine growth. For surfaces that have marine growth the surface roughness is taken as the marine growth thickness up to a maximum of 50mm. Member segments The number of segments that a distributed load is broken into along a member to simulate the curved profile of the applied load. Marine growth load case This is the load case that the self weight of the marine growth will go into. Because marine growth doesn't change with waves or currents its self weight is put into its own load case. You can the combine it with the wave and current load cases using combination load cases in the normal way. CDM parameters These are the drag (CD), inertia (CM) and lift coefficients that are used in the sea load calculations on submerged members. Guidance for selection of these parameters is available in various code standards including API RP 2A. In the absence of any other information you could consider using CD=0.65 & CM=1.60 for clean tubular members or CD=1.05 & CM=1.20 for fouled tubular members. Values of CD and CM for other cross section types may be obtained from international codes and standards including DnV codes. The "Smooth" coefficients are used if k/D <= 0.0001, the "Rough" coefficients are used if k/D >= 0.01 and an interpolation between the "Smooth" and "Rough" coefficients are used if 0.0001 < k/D < 0.0, where k is the surface roughness and D is the largest dimension or diameter of the member.

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Graphical Input Marine growth parameters Any structural element submerged in water will have marine growth developed on its wetted surfaces. Such growth effectively increases the element's exposed area to waves which in turn attracts higher wave loading. For this reason the marine growth parameters applicable to the region where the structure is located needs to be considered in the sea load analysis. At least two lines of marine growth data are required, with the marine growth only occurring between the levels and not outside them. If the thickness or density is different in adjacent levels then they are assumed to vary linearly between the levels. Marine growth levels are relative to the SPACE GASS origin and are negative if the location is below the origin.

Scenarios Each scenario represents the motion of a wave and normally covers a full wavelength. If the "Selection Criterion" is set to "None" then multiple load cases representing the various positions of the wave are generated for each scenario. If the "Selection Criterion" is set to "Maximum overturning moment" or "Maximum base shear" then only one load case will be generated for each scenario. You can specify multiple scenarios, each with its own direction and load case(s).

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The following parameters are scenario specific.

Load case / Starting load case This is the first of the load cases that will be generated for the current scenario. If the “Selection Criterion” is set to “None” then the last load case for the scenario = Starting load case + Steps – 1, otherwise there is only one load case per scenario.

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Still water depth Is based on the general water depth, but also includes any tide and/or storm surge at the time of occurrence of waves. It cannot be less than the general water depth. Wave kinematics factor Guidance for selection of the wave kinematics factor is available in various code standards including API RP 2A. In the absence of any other information you could consider using 0.85 to 0.95 for extreme cyclonic or storm waves, or 1.00 for normal operating and fatigue waves. Wave height The wave height is the vertical distance between the wave crest and the trough. Wave period The wave period is the time it takes for the wave to travel through one wavelength (ie. the distance between consecutive wave crests) relative to a stationary point. The sea load output also reports the "Apparent Period", which is the wave period relative to a point travelling with the current (if a current exists). A current in the wave direction tends to stretch the wavelength and increases the apparent period, while an opposing current shortens them. This is the Doppler effect of the current on the wave. Start phase and phase increment Sea loading on a marine structure varies continuously as the wave passes through the structure with the maximum loading occurring at a specific position of the wave with respect to the structure. To determine the maximum loading, the wave is simulated to pass through the structure beginning with the start phase position and stepping the wave at the specified phase increment. A phase of 0 degrees corresponds with the wave crest at the origin (ie. the 0,0,0 position) of your model. 360 degrees is equivalent to one wavelength. Steps This is the number of phase increment steps considered during the analysis. End phase = Start phase + (Steps x Phase increment). If the “Selection Criterion” is set to “None” then the number of load cases generated for a scenario is equal to the number of steps, otherwise there is just one load case per scenario. Wave theory Selection of the wave theory for analysis of any wave depends on the wave parameters and the water depth. A general guidance for selection of the wave

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SPACE GASS 12 User Manual theory can be obtained from the American Petroleum Institute's Recommended Practice API RP 2A. In the absence of other information the following could be considered as a rough guideline: if 0.000 <= H/(g.T^2) <= 0.001 and 0.01 <= d/(g.T^2) <= 0.2 then select Airy's linear theory if 0.001 <= H/(g.T^2) <= 0.02 and 0.005 <= d/(g.T^2) <= 0.2 then select Stokes' 5th Order non-linear theory where H = wave height, d = still water depth, T = wave period and g = gravitational acceleration. Selection criterion Sea loading on the structure is evaluated at each position of the wave as it passes through the structure and, depending on the "Selection criterion" specified in the form, the critical position is selected as the position of the wave that results in the maximum base shear or the maximum overturning moment at the mudline. If set to "None" then a load case is generated at each wave position and no attempt is made to determine the critical one. Note that the base shear and overturning moment calculations are based on the horizontal wave and current loads only and exclude any vertical loads from buoyancy, self weight, marine growth or other applied loads. Wave and current direction These are the directions of the approaching wave and water current relative to the global X-axis. Direction angles are positive anti-clockwise from global X when viewed in plan. Ocean currents Currents occurring simultaneously with waves significantly influence the total sea loading and need to be considered in the analysis. Current profiles should be input for each scenario. They are combined with the wave velocities determined by the wave analysis before Morison's equation is applied. At least two lines of ocean current data are required, with the currents only occurring between the levels and not outside them. If the current is different in adjacent levels then it is assumed to vary linearly between the levels. Ocean current levels are relative to the SPACE GASS origin and are negative if the location is below the origin.

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Graphical Input The "Blockage Factor" controls how much the current stream in the vicinity of the structure is reduced from the specified "free stream" value by blockage. In other words, the presence of the structure causes the incident flow to diverge. Some of the incident flow goes around the structure rather than through it, and the current speed within the structure is reduced. Blockage factors ranging from 0.7 to 1.0 are typical, with 1.0 representing no blockage.

Doppler effect When waves and currents occur together, an "Apparent Period" relative to the current is determined, accounting for the Doppler effect of the current on the wave. A current in the wave direction tends to stretch the wavelength and increases the apparent period, while an opposing current shortens them. The apparent wave period is determined from API RP 2A Figure 2.3.1-2 if -0.015 <= V/gT <= 0.025, where V is the current component in the wave direction, g is the acceleration due to gravity and T is the actual wave period relative to a stationary point. If V/gT is outside of the above mentioned limits then a warning is issued and the results may not be accurate.

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Moving loads This tool in the renderer lets you automatically generate loads on a structure that model moving vehicles, cranes or other moving load sources. Each moving load scenario can contain one or more vehicles with multiple wheels travelling along paths that consist of straight and/or curved segments. You can also specify the speed, initial delay, time interval and load factor for each vehicle.

Overview Moving loads are simply a set of load cases that contain vehicle loads that are in a different position in each successive load case. If you view the load cases one after another, it gives the appearance of the loads moving along the model. The Moving Loads tool simply generates these load cases. In order to proceed, you must first create a scenario that contains the set of load cases to be generated. The scenario has a name, a starting load case number and a time interval that represents the time between successive load cases. You must then add one or more vehicles to the scenario, each of which contains a set of wheels (with their positions and loads), a travel path (which determines where the vehicle travels), a speed, a delay and a load factor (which is applied to all of the vehicle's wheel loads). Vehicles are imported into the scenario from libraries of standard and custom vehicles. A vehicle's travel path can go in any direction and around corners or along an arc. The vehicle's speed multiplied by the scenario's time interval equals the distance travelled by the vehicle in successive load cases. You can add more than one vehicle to a scenario, in which case each vehicle moves along its own travel path at its own speed with whatever initial delay you specify. When the Moving Loads tool generates the load cases for a scenario, it calculates the position of each vehicle along its travel path for each time interval and then distributes the loads from each wheel onto the members that support it. Each wheel of a vehicle is active if it is within the ends of the vehicle's travel path and within the loading area that you can specify. Wheel loads are applied only to the members you have selected, as member concentrated loads or node loads. At any time after creating a scenario, you can produce an animated view of the wheels moving along your model. After the loads have been generated, you can use

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Graphical Input the keyboard PageUp/Dn keys to scroll through the load cases and see the loads moving across your model. Normally only one scenario is required, however you can create multiple scenarios if you wish to model different situations such as different combinations of vehicles moving along a bridge.

The Moving Loads tool does not generate loads from static sources such as bridge lane loads. They must be input using the normal load input tools in SPACE GASS. The Moving Loads tool has facilities for combining static load cases with the generated moving load cases.

Procedure To operate the moving loads tool, from within the renderer select all the members in your model that directly support the moving vehicle’s wheels, click the right mouse button and then select "Generate Moving Loads" from the menu that appears. Alternatively, you can click the moving load button (shown below) from the renderer's top toolbar and select the "Generate Moving Loads" option.

If you haven’t previously defined any moving load data for this job, the following form appears.

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This form lets you quickly define the data for an initial scenario. After you have clicked the Ok button, you can proceed to add vehicles to the scenario or you can define additional scenarios.

Scenarios A scenario is a collection of vehicles that move across the structure in steps defined by the scenario time interval. You will commonly need just one scenario, however you can have multiple scenarios if required, each with its own set of load cases, time interval, vehicles and travel paths. For example, a two-lane bridge model could have scenario 1 with the heaviest vehicle in lane 1 and the lightest vehicle in lane 2, while scenario 2 could have the heaviest vehicle in lane 2 and the lightest vehicle in lane 1. A set of load cases is created for each scenario, beginning at the starting load case specified for that scenario and incremented by 1 for each time interval. The total number of load cases depends on how long it takes for all vehicles in the scenario to reach the end of their travel paths. You can add a new scenario, delete a scenario or edit the properties of a scenario by clicking the appropriate button at the bottom of the travel paths form (see below). Alternatively, you can right-click on "Scenarios" or on the scenario name

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Graphical Input in the tree at the left-hand side of the form and then select the appropriate item from the floating menu to add, delete or edit a scenario.

If you have more than one scenario, ensure that the load cases do not overlap between scenarios. If this happens, it will be detected by SPACE GASS and the moving load generation will not proceed.

Combining scenarios with other static load cases The load cases generated for a scenario can be combined with other static load cases using the grid section at the bottom of the scenario properties form. This is necessary when the moving loads need to be combined with other load cases such as dead loads, live loads, lane loads, etc.

For example, in the above form, the scenario 1 moving loads will be combined with static load case 9 to form a set of combination load cases starting at load case 100. A further set of combination load cases starting at 200 will combine the scenario 1 load cases (factored by 0.9) with static load case 6.

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SPACE GASS 12 User Manual You can see this has the potential to generate a huge number of load cases and you may, therefore, need to increase the "Maximum load cases" value via the "Problem size limits" item of the Config menu. If you need to combine a scenario with more than one static primary or combination load case, simply create a combination load case that combines the primary and combination load cases into a new combination load case first and then combine the scenario with that new combination load case. Remember that combination load cases can be combined into further combinations up to four levels deep. Combining scenarios with other load cases increases the risk of overwriting existing load cases and having load case clashes due to overlapping of load cases between scenarios and combinations. SPACE GASS checks for these occurrences and prevents the load generation from proceeding if any problems are detected.

Vehicles To add vehicles to a scenario, click the "Add Vehicle" button at the bottom of the main moving loads form and then click the vehicle library button to select a vehicle from a vehicle library. For each vehicle you must also specify a speed, a delay, a load factor and a travel path.

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Graphical Input

The vehicle speed, combined with the scenario time interval, determines the distance between vehicle positions in successive load cases. If a delay is specified, the vehicle doesn’t move or have its wheel loads applied to the structure until the end of the delay period. The load factor is applied to all wheel loads in the vehicle. It can be used, for example, where a load reduction is allowed when multiple roadway lanes are loaded simultaneously. In order to model a reversing vehicle, you should specify a negative speed. In this case, the vehicle will still move along the travel path starting from the same end, but will be moving in reverse. The vehicle datum, which coincides with the front-center of the vehicle, is the point on the vehicle that tracks along the travel path. You can add a new vehicle, delete a vehicle or edit the properties of a vehicle by clicking the appropriate button at the bottom of the main moving loads form (see below). Alternatively, you can click the right mouse button on a scenario or a

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SPACE GASS 12 User Manual vehicle name in the tree at the left-hand side of the form and then select the appropriate item from the floating menu to add, delete or edit a vehicle.

Travel paths The travel path for each vehicle consists of one or more segments between stations that can be positioned in a number of ways. The travel path stations can be defined by node numbers, coordinates or node numbers offset by coordinates. A segment is assumed to be straight unless you specify a radius, in which case the curve is applied to the segment between the station that has the radius and the previous station. For example, if you have just two stations and wish to have a curved travel path between them, you would specify the radius at the second station. A curved travel path follows the shortest arc between the ends of the segment in a clockwise direction when looking from above. If you use a negative radius then the travel path will follow an anti-clockwise direction. A travel path can go in any direction across your structure, regardless of where the nodes and members are located. Travel paths do not need to be lined up with members in the structure. Travel path stations are only required at the two ends of the travel path and at changes in direction or radius. Note that the vertical coordinate in the travel path has no effect on the generated loads and is only used for visual purposes when viewing the animated vehicle's movement (see below).

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Graphical Input

For example, the travel path shown in the above form follows a straight line offset 8.1m sideways in the Z-axis direction from the line connecting nodes 1 and 9. If you have many travel path stations, you can change their order by using the promote (up arrow) and demote (down arrow) buttons on the right-hand side of the form. You can select a travel path graphically by clicking the "Select Path" button. Normally, you have to specify the travel path for each vehicle, however for simple structures such as beams or monorails, the first vehicle’s travel path will default to the beam or monorail nodes when you define moving load data for the first time. In this case, all of the intermediate nodes will be included even though intermediate stations are not required except at changes in direction.

Animated vehicle view You can also create an animated view of a vehicle's wheels moving along the travel path by clicking the "View Path" button in the main moving loads form. You can then set the animation speed and other parameters in the form shown below before clicking Ok to start the animation. Note that you can pause the animation at any time by pressing the space bar or you can cancel it by clicking the Esc key.

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Loading area limits Each wheel in a vehicle is active while it is between normals that extend from the two ends of the travel path for that vehicle. It is possible, however, that you may want wheels to become inactive at certain times even though they are still within the extents of the travel path. For example, if a wheel moves off the side of a bridge or move off the end of a skew bridge, you may want it to become inactive before it reaches the end of its travel path. You can achieve this by clicking the "Ignore wheel that transfer the load to just one member" option in the main moving

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Graphical Input loads form. This has the effect of ignoring wheels that would have their load distributed to just one member unless the wheel is directly on that one member. It solves the problem of deactivating wheels that move off the structure in most cases. For situations in which the above option is not suitable, you can specify a polygon that defines a loading area. Wheels that are outside of the loading area are treated as inactive. You can define the loading area graphically by clicking the "Define/View Loading Area" button in the main moving loads form and then selecting points around your model that represent the limits of the loading area. The loading area as displayed ignores the height of the points you select and is drawn at the topmost level of the members being loaded as shown below.

Load distribution Wheel loads are applied only to the members that are selected graphically. Members that are not selected graphically will not have any wheel loads applied directly to them. For example, for a bridge design, it would be normal to select all of the members in the bridge deck that directly support the roadway surface and not the members lower down that are not directly subjected to the wheel loads. For a wheel that is positioned exactly on a member, its load is applied directly to that member. If the wheel is exactly positioned on a number of members then the load is shared equally between them. For a wheel that is not positioned exactly on a member, its load is distributed onto the adjacent members in inverse proportion to the closest distance between the member and the wheel.

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SPACE GASS 12 User Manual If the "Apply wheel loads to closest member only" option is selected in the main moving loads form then each wheel load will be applied only to the member that is closest to it rather than to all the members adjacent to the wheel.

Load generation Once you have specified all the required vehicles and their travel paths, you should click the Ok button to initiate the load generation. You can then use the keyboard PageUp/Dn keys to scroll through the load cases and see the generated loads moving across your structure.

Load cases All primary and combination load cases generated with the moving loads module are given load case titles that reflect their properties. Each title includes a heading and a notes field. Please ensure that you don’t edit or delete the notes field as it is the means by which the program keeps track of which load cases belong to which scenario.

Vehicle libraries The vehicle libraries contain all of the standard vehicles for a number of countries and these can be used whenever standard vehicle types are required. You can also create your own custom libraries containing custom vehicles with any arrangement of wheel positions and loads. You can access the vehicle library by clicking the properties form.

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button in the vehicle

Graphical Input

You can’t modify any of the standard libraries, however you can create your own custom vehicle libraries to which your own vehicles can then be added. You can create a custom library by clicking the "Add Library" button at the bottom of the above form. Alternatively, you can click the right mouse button on "Vehicle Libraries" in the tree of the form and then select "Add Library" from the floating menu. You can create a custom vehicle by clicking the "Add Vehicle" button at the bottom of the above form. Alternatively, you can click the right mouse button on a custom library name in the tree of the form and then select "Add Vehicle" from the floating menu.

Envelopes After the job has been analysed, you can display bending moment or shear force envelopes by clicking the "Selected Load Cases" item in the load cases combo box in the top toolbar and then typing in the range of load cases that have just been generated for a scenario. For example, if load cases 1 to 35 were generated, you should type 1-35 into the load cases field. Note that this may not always be necessary as the load cases field is automatically set by SPACE GASS for the first scenario whenever moving loads are generated.

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On the side toolbar, you should then ensure that the envelope button depressed and the desired bending moment is depressed.

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or shear force

is

diagram button

Graphical Input

Varying plate pressure loads This tool is only available in the traditional graphics window. For retaining structures such as tanks or retaining walls, or structures subjected to other variable pressure distributions from wind and the like, the resulting pressure loads on plates can be generated using this tool. The pressure variation can be linear or based on an equation that you specify. The tool works by you defining the pressure variation and a "load axis" along which the pressure distribution is defined. The pressure is then projected normal to the load axis onto each plate that you have selected. The lateral position of each plate relative to the load axis is not important. For example, a plate a long way from the load axis will get the same pressure as a plate close to it. Similarly, a plate on one side of the load axis will get the same pressure as a plate on the other side. For calculating the pressure on the walls of tanks or retaining structures, the load axis would normally be vertical and the pressure on a plate with its centre at height h would be the same as the pressure on the load axis at height h. For other structures, such as a distribution of wind loads applied to a roof, it might be more convenient to have the load axis horizontal or maybe even parallel to the roof slope. Plates that are beyond the ends of the load axis are not loaded. For example, if you have a tank that is 4m high and the load axis extends from the base of the tank vertically up to the 3m mark, the plates in the top 1m of the tank walls will not be loaded.

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Load Axis and Pressure Distribution

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Graphical Input

Resulting Pressure Applied to the Plates

If the pressure variation is defined by an equation, the equation must have "x" as the variable representing the distance along the load axis and can include any of the operators "+", "-", "*", "/", "\”, "%" and "^". It can also include any of the functions sin, cos, tan, asin, acos, atan, sqrt, factorial, abs, log, ln and exp. For example, the pressure on the walls of a bulk solids container could be represented by the equation Pressure =  rc(1-e(-z/z0))/, where, for a typical coal container could have values of  =10.8, rc=0.88, z0=4.03 and =0.62. This could be entered into the SPACE GASS equation field as 10.8*0.88*(1-exp(-x/4.03))/0.62, where "x" is the distance along the load axis and represents "z" in the original equation.

The procedure is as follows.

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SPACE GASS 12 User Manual 1. Select the plates you wish to load, click the right mouse button and then select "Varying Pressure Loads" from the floating menu that appears. OR Select "Varying Plate Pressure Loads" from the Loads menu, select the plates you wish to load, click the right mouse button and then click Ok.

2. Pick two points that represent the load axis along which the pressure variation will be distributed. Remember that when picking points, you can use the mouse or you can simply type in the coordinates of the desired point(s). For more information, see "Using the keyboard to position points".

3. In the form that appears (as follows), change the data to suit your requirements and then click the Ok button.

The load variation can be linear for cases such as tanks subjected to hydrostatic loads or, for more complex profiles, can be defined by an equation that you specify as explained above. If you specify "Local" axes then the pressure load will be applied in the

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Graphical Input local z-axis direction (ie. normal to the plane of the plate). If you specify "Global" axes then you must also specify a global XYZ vector that represents the direction of the pressure load.

4. The pressure loads are then calculated and applied to the selected plates. 5. Select more plates to load, or press ESC or the right mouse button to exit from the tool. See also Plate pressure data.

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Copy node loads This tool is replicated in the renderer and in the traditional graphics window. The Copy Node Loads tool lets you copy loads, prescribed displacements and lumped masses from a loaded node to a selection of destination nodes. The renderer version After selecting the destination nodes, right-click and select "Copy Node Loads" from the menu that appears. You should then click the source node, followed by specifying the load cases that the loads are to be copied from in the form shown below. If you tick the "Delete and replace loads on destination nodes for the specified load cases" option then all pre-existing node loads, prescribed displacements and lumped masses on the selected destination nodes contained within the selected load cases will be deleted first. If it is unticked then the loads being copied will be added to the pre-existing loads.

The traditional graphics window version The procedure is the reverse of the renderer procedure above. After selecting the source node, right-click and select "Copy Node Loads" from the menu that appears. You should then select the destination nodes, right-click and then select Ok to have the loads copied. All pre-existing node loads, prescribed displacements and lumped masses on the selected destination nodes contained within the selected load cases will be deleted and replaced by the copied loads.

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Graphical Input

Copy member loads This tool is replicated in the renderer and in the traditional graphics window. The Copy Node Loads tool lets you copy loads from a loaded member to a selection of destination members. The renderer version After selecting the destination members, right-click and select "Copy Member Loads" from the menu that appears. You should then click the source member, followed by specifying the load cases that the loads are to be copied from in the form shown below. If you tick the "Delete and replace loads on destination members for the specified load cases" option then all pre-existing member loads on the selected destination members contained within the selected load cases will be deleted first. If it is unticked then the loads being copied will be added to the pre-existing loads.

The traditional graphics window version The procedure is the reverse of the renderer procedure above. After selecting the source member, right-click and select "Copy Member Loads" from the menu that appears. You should then select the destination members, right-click and then select Ok to have the loads copied. All pre-existing member loads on the selected destination members contained within the selected load cases will be deleted and replaced by the copied loads.

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Copy plate loads This tool is replicated in the renderer and in the traditional graphics window. The Copy Plate Loads tool lets you copy loads from a loaded plate to a selection of destination plates. The renderer version After selecting the destination plates, right-click and select "Copy Plate Loads" from the menu that appears. You should then click the source plate, followed by specifying the load cases that the loads are to be copied from in the form shown below. If you tick the "Delete and replace loads on destination plates for the specified load cases" option then all pre-existing plate loads on the selected destination plates contained within the selected load cases will be deleted first. If it is unticked then the loads being copied will be added to the pre-existing loads.

The traditional graphics window version The procedure is the reverse of the renderer procedure above. After selecting the source plate, right-click and select "Copy Plate Loads" from the menu that appears. You should then select the destination plates, right-click and then select Ok to have the loads copied. All pre-existing plate loads on the selected destination plates contained within the selected load cases will be deleted and replaced by the copied loads.

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Graphical Input

Managing load cases This tool is replicated in the renderer and in the traditional graphics window. The renderer version You can use the Manage Load Cases tool to copy, renumber or delete entire load cases by clicking the

button in the top toolbar of the renderer.

When specifying the source load case list, you can either list them directly, or you button to display and select from a list of the load cases can click the currently in the job as shown below.

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The traditional graphics window version You can use the Manage Load Cases tool to copy, renumber or delete one load case at a time by clicking the

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button in the traditional graphics window.

Graphical Input

View nodes / members / plates You can show or hide nodes, members or plates by clicking the , or toolbar buttons or selecting "Nodes", "Members" or "Plates" from the View menu. If the nodes, members or plates are hidden then any tools that require nodes, members or plates to be selected are suppressed. For example, if the nodes are hidden then node loads cannot be input or edited graphically.

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View node / member / plate properties You can show graphical representations of node restraints, member hinges, master, , or toolbar buttons or slave constraints or offsets by clicking the selecting "Node Restraints", "Member Hinges", "Master-Slave Constraints" or "Offsets" from the View menu.

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Graphical Input

View global origin You can show the global origin by clicking the (renderer) or (traditional graphics window) toolbar button or selecting "Global Origin" from the View menu.

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View local axes You can show the member and plate local axes by clicking the or selecting "Local Axes" from the View menu.

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toolbar button

Graphical Input

View member origins It is often useful to be able to see at which end of a member is its origin, as it affects the placement of member fixities, offsets, loads, etc. You can show the member origins (shown in red below) by clicking the toolbar of the renderer.

button in the bottom

Note that you can reverse the direction of members using the Reverse member direction tool.

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View labelling and annotation This tool is replicated in the renderer and in the traditional graphics window. The renderer version You can show various text labelling and annotation options by clicking the button in the bottom toolbar of the renderer. Once you have selected or de-selected the desired labelling items you must click anywhere in the graphics area to have the labelling change applied.

Clicking the "Labelling Preferences" item takes you to the following form from where you can change colors, formatting, etc.

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Graphical Input

The traditional graphics window version You can show various text labelling and annotation options by clicking the toolbar button or selecting "Labelling and Annotation" from the View menu or the floating menu.

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Load case titles viewer The load case titles viewer can be opened from within the renderer by clicking the . The viewer stays open until you close it or load case titles viewer button change jobs. It is a handy means of seeing the details of your load cases while you are working with other tools.

button next to them. Note that many of the load case input fields have a Clicking this button also lets you see which load cases exist in your job, plus you can select from the displayed list.

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Graphical Input

Load case titles can be input via the load case titles datasheet from within the traditional graphics window. For more information refer to Load case titles. You can also input/edit load case titles via the combination load cases grid in the renderer by right-clicking a column heading or a cell in the first column.

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View results in local XY or XZ plane You can restrict the bending moment, shear force or stress diagrams to either or both of the member’s local XY or XZ planes by clicking one of the or toolbar buttons or selecting "Results in Local XY Plane" or "Results in Local XZ Plane" from the View menu.

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Graphical Input

View diagrams You can show loading diagrams, displacement diagrams, bending moment diagrams, shear force diagrams, axial force diagrams, torsion diagrams, stress diagrams and reactions by clicking the , , , , , , or toolbar buttons or selecting from the matching items in the View menu. Diagrams of different types can be superimposed together. For example, it is possible to include both bending moment and shear force diagrams together. In addition, diagrams can be toggled on and off by clicking the button repeatedly.

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View plate contours You can use the 3D renderer to show colored contour diagrams for plate forces, moments and stresses by clicking the Contours" from the View menu.

toolbar button or selecting "Plate

The following form allows you to select the type of contour diagram you wish to display as well as specifying its smoothing, color and labelling settings.

If contour smoothing is turned on then the contours appear as continuous color gradients rather than a discrete color for each plate element. Contour diagrams are generated from the force, moment and stress values at each node. The value at a given node can be determined by simply averaging the values

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Graphical Input from each element that connects to it (non-weighted averaging) or the contribution from each element can be weighted depending on how far the centre of the element is from the node (weighted averaging). For full details of the force, moment and stress contours that can be displayed, refer to "Sign conventions". The colors in a contour diagram can be changed by double-clicking any of the three color icons and then selecting the desired color, or by clicking the "Color Picker" button. If you wish to display the full range of contour values, ensure that the "Full range" option is ticked. If not, you can "zoom in" on a particular range of contour values by unticking the "Full range" option and specifying upper and lower limits. Values that fall within the upper and lower limits will be colored depending on where they fall within the specified color spectrum, and any values that fall outside the limits will be given the same color as values that fall on the upper and lower limits. If you find that the contour diagram is predominantly showing the "middle" color, you may be able to display more color detail by setting a narrower contour range. Each plate can be labelled with its contour value if desired.

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Graphical Input

View envelope You can display an envelope of any currently displayed diagrams by clicking the toolbar button or selecting "Envelope" from the View menu. You can specify (a) just minimums, (b) just maximums, (c) both minimums and maximums or (d) absolute maximums. The load cases included in the envelope are the ones currently selected and displayed in the load case selection combo box in the top toolbar. If you change the load case selection then the envelope will be updated accordingly. Envelopes of analysis results can also be obtained in output reports, including envelopes that take their maximums and minimums from end A, end B or both ends of a member. For more information, refer to Output

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View dynamic mode shapes After a dynamic frequency analysis, you can display animated mode shapes for all the modes analysed by clicking the Shapes" from the View menu.

toolbar button or selecting "Dynamic Mode

Once initiated, the following keyboard commands are available. Operation Display mode shapes 1 to 9 Display the next mode shape Display the previous mode shape Change to load case Change the display from animated to static Change the display from static to animated Increase the amplitude (scale) Decrease the amplitude (scale) Increase the frequency (speed) Decrease the frequency (speed)

Keystrokes 1-9 Page down Page up C S A Right arrow Left arrow Up arrow Down arrow

You can exit from the dynamic mode shapes commands by pressing ESC or the right mouse button. This also causes any animation to stop and revert back to a static display.

If you use REDRAW or any other tool which causes the graphics display area to be regenerated while a dynamic mode shape is displayed, it will revert back to an animated display, and the dynamic mode shapes commands will again become active. Some examples of mode shapes for a plane grid from the dynamic frequency analysis module are shown following.

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Graphical Input

1st dynamic mode shape for plane grid

4th dynamic mode shape for plane grid

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View buckling mode shapes After a buckling analysis, you can display the buckling mode shapes by clicking the

toolbar button or selecting "Buckling Mode Shapes" from the View menu.

You can limit the number of buckling modes shown by defining a filter and specifying a list of the buckling modes required. For 2D models, it is a good idea to view the buckling mode shapes from a 3D viewpoint so that any out-of-plane buckling modes can be observed.

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Graphical Input

View steel member design groups You can show steel member design groups as thick lines superimposed over the analysis model by clicking the toolbar button or selecting "Steel Member Design Groups" from the View menu. The groups are shown slightly shorter than their actual length so that you can easily see where they start and finish.

To view the properties of a steel member design group you can simply click the right mouse button on any part of a design group and then select "Steel Member Design Input (Form)" from the floating menu. Note that this can be done regardless of whether the groups are displayed or not. See also Steel member design data

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View steel member top flanges It is important to know which is the top flange for steel members so that the restraints you specify for the top and bottom flanges do not get mixed up. This tool lets you display them as small triangles that touch the top flange of each analysis member. You can show the top flanges by clicking the Member Top Flanges" from the View menu.

toolbar button or selecting "Steel

The top flange for a steel design group is taken to be the same as the top flange for the first analysis member in the design group. Therefore, to find the top flange of a design group you must look at just the first member in the group. See also Steel member design data

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Graphical Input

View steel member flange restraints If you are not sure where your steel design flange restraints are actually located along the members, you can use this tool to show them graphically. You can show the flange restraints by clicking the toolbar button or selecting "Steel Member Flange Restraints" from the View menu.

Displays all of the flange restraints that you have specified for each design group. The flange restraints are shown adjacent to their location on the top and bottom flanges. See also Steel member design data

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View steel member design results If a steel member design has been performed, this tool shows the design results color coded for the various levels of load factor or stress ratio achieved. You can view the design results by clicking the toolbar button or selecting "Steel Member Design Results" from the View menu.

The color divisions are chosen as follows. Load Factors: >= 2.00 >= 1.10 >= 1.00 < 1.00 < 0.90 < 0.50 Design error Not designed

Stress Ratios: <= 0.50 <= 0.90 <= 1.00 > 1.00 > 1.10 > 2.00 Design error Not designed

(Pass) (Pass) (Pass) (Fail) (Fail) (Fail)

You can change the colors by selecting "Graphics Colors" from the Config menu. To view brief design result details of a steel member design group (see below) you can simply click the right mouse button on any part of a design group and then select "Steel Member Design Results" from the floating menu. You can then simply click on other members to view their results. Note that this can be done regardless of whether the design results are displayed or not.

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Graphical Input

You can also use filters to restrict the display of members based on their design results. See also Steel member design data

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Query frame You can query any node, member or plate in your model by simply double-clicking on it. Alternatively, you can do the query by clicking the "Frame" from the Query menu.


While the form is open, you can simply click on any other nodes, members or plates to have their attributes displayed. For full details, refer to Node properties, Member properties or Plate properties.

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Graphical Input

Query analysis results You can query the analysis results graphically in either of two ways: To click on a node, member or plate and get its analysis results in a scrollable window Click the toolbar button or select "Analysis Results" from the Query menu or click the "Results" button in the "Node Properties", "Member Properties" or "Plate properties" forms. The scrollable results form shown below displays a useful summary of the analysis results for those nodes, members or plates you select.

While the form is open, you can simply click on any other nodes, members or plates to have their results displayed. To move a crosshair along a member and get its analysis results at the crosshair location Choose an item other than "Frame" and "Analysis Results" from the Query menu.

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SPACE GASS 12 User Manual This method lets you nominate a load case and the number of intermediate member stations as shown in the form as follows, followed by picking a member to query.

A crosshair cursor is then positioned at the node A end of the member and a line of information near the bottom of the SPACE GASS window shows the analysis results for the selected member at the crosshair location. You can then use the keyboard arrow keys to move the crosshair cursor to any location on any member in the frame, with the coincident analysis results being continuously updated and reported in the information line. To get a fully detailed analysis report, refer to Output.

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Graphical Input

Query steel member design results After a steel member design, you can query the design results by clicking the toolbar button or selecting "Steel Member Design Results" from the Query menu. The scrollable results form shown below displays a useful summary of the design results for those members you select.

While the form is open, you can simply click on any other members to have their design results displayed. To get a fully detailed steel member design report, refer to Output.

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Redraw This tool is not applicable to the renderer, as the model is always kept up to date, however in the traditional graphics window a redraw is sometimes required to "clean-up" the image. You can redraw the graphics display area with the same scale, viewpoint and contents by clicking the toolbar button or selecting "Redraw" from the View menu or the floating menu. The REDRAW facility can be useful for removing stray lines or text which are sometimes left after a MOVE, COPY, ROTATE, MIRROR or other graphics operation.

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Graphical Input

Zoom This tool is replicated in the renderer and in the traditional graphics window. The Zoom tool allows you to zoom in or out on the entire structure or just a part of it. The renderer version You can zoom, pan or rotate your model via the mouse scrollwheel or by dragging it around using the left or right mouse buttons as shown below. Alternatively, you can press the right arrow key to "Zoom full" or the left arrow key to "Zoom previous". You can also zoom in on a selection of nodes, members or plates by selecting the desired items, right-clicking and then selecting "Zoom Selected" from the menu that appears.

The traditional graphics window version Zooming can be most conveniently done using the mousewheel or keyboard arrow keys as described in "Shortcuts". For example, while viewing the structure graphically, just use the mousewheel to zoom in or out. Alternatively, you can zoom by clicking the or the floating menu.

toolbar button or selecting "Zoom" from the View menu

There are four zoom modes as follows. 1. ZOOM full - redraws the entire structure at a scale that allows it to fit comfortably on the screen. 2. ZOOM window - requires you to place a window around a portion of the structure which it then enlarges and redraws to fill the screen.

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SPACE GASS 12 User Manual 3. ZOOM in/out - requires you to position the graphics cursor at the zoom centre and then click the left mouse button to ZOOM in or the right mouse button to ZOOM out. 4. ZOOM previous - reverts back to the previously displayed view. If you have selected ZOOM Window, you can revert to ZOOM Full or ZOOM Previous by pressing the keyboard F or P keys while selecting the window.

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Graphical Input

Pan This tool is replicated in the renderer and in the traditional graphics window. This tool allows you to move the structure in any direction on the screen. It is useful if you cannot see the entire structure at once and you don't want to change the scale. You simply move the structure until you can see the desired portion. The renderer version You can zoom, pan or rotate your model via the mouse scrollwheel or by dragging it around using the left or right mouse buttons as shown below.

The traditional graphics window version Panning can be most conveniently done using the mousewheel or keyboard arrow keys as described in "Shortcuts". For example, while viewing the structure graphically, just hold down the CTRL key and use the mousewheel to pan up or down, or hold down the SHIFT key and use the mousewheel to pan left or right. Alternatively, you can pan by clicking the from the View menu or the floating menu.

toolbar button or selecting "Pan"

The sequence of operation is as follows. 1. Pick two points that represent the relative movement through which the structure is to be panned across the screen. 2. The structure is redrawn at the new position.

The PAN operation does not change node coordinates, it simply translates your viewpoint.

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Scales Parts of this tool are replicated in the renderer and in the traditional graphics window. The Scales tool allows you to change the scales of the undeformed frame or any of the superimposed diagrams. The renderer version In the renderer you can change the scale of your model by zooming using the mouse scrollwheel and you can change the scale of your loads (if they are displayed) by clicking the load scales button

or the load auto-scaling button

in the top toolbar of the renderer. Alternatively, you can change the load scale by holding down the L key while rotating the mouse scrollwheel.

The traditional graphics window version Changing scales can be most conveniently done using the mousewheel or keyboard arrow keys as described in "Shortcuts". For example, while viewing the structure graphically, just use the mousewheel to zoom in or out, or hold down the M key and use the mousewheel to change the scale of a displayed bending moment diagram, etc. Alternatively, you can change scales by clicking the toolbar button or selecting "Scale" from the View menu or the floating menu. All scales initially default to values that allow the diagrams to fit neatly into the available graphics display area. If you change any of the scales, they are retained with the job.

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Graphical Input

The "Displacements factor" and "Buckling mode factor" settings are distortion factors rather than scales. Increasing their values causes the relevant diagrams to increase in size. Increasing any of the other "Scale" settings causes the relevant diagrams to be reduced in size.

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Find This tool is replicated in the renderer and in the traditional graphics window. You can use the Find tool to quickly locate nodes, members or plates in your model by clicking the

toolbar button.

The renderer version

In the renderer you can also find all the members or plates with a particular section or material by clicking the desired section or material in its property panel and then having all the matching members or plates selected.

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Graphical Input

The traditional graphics window version

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You can find nodes, members or plates by listing their numbers directly or by specifying their properties or the nodes/members/plates to which they are connected. Only those nodes, members or plates that satisfy all of the find criteria in the form are found. When a node, member or plate is found, it is highlighted graphically the same as if you had selected it by picking it with the mouse. You can use the highlighting simply as a visual reference to see where the found nodes, members or plates are in your structure, or you can click a toolbar button or click the right mouse button and choose from the floating menu that appears to perform an operation on the selected nodes, members or plates. You can cancel the highlighting by pressing the keyboard ESC key or by selecting "Cancel" from the floating menu.

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Graphical Input

If you are searching for members of a certain section or material, you can also just click the desired section or material in the properties panel of the renderer to highlight all the members in your model that use it. After the Find tool highlights the nodes, members or plates you are searching for, you can perform many graphics operations on them by right-clicking and then selecting from the menu that appears.

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Filters The filter tool allows you to restrict the amount of data that is displayed in the graphics display area or in output reports. You can use it to restrict the display to specific nodes, node types, members, member types, plates, plate types, section properties, material properties, load types, buckling modes, steel members, steel connections, axis limits or any combinations of these. To create a filter from nodes, members or plates selected graphically Select some nodes, members or plates graphically by picking them or by using the "Find" tool and then select "Create Filter" from the floating menu, after which the following form appears.

To save the current selection as a filter, just click the combo box in the above form, select a filter number and then type in the filter’s name. You can overwrite previously saved filters or you can select and name an unused filter. An alternative method of creating a filter from nodes, members or plates selected graphically is to use the "Select" buttons in the main filters form as explained below. To create or edit filters Click the menu.

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toolbar button or select "Filters" from the View menu or the floating

Graphical Input

For each filter you can select one or more check boxes and then specify the corresponding items to be included in the filter. For example, if you specify a member list of 1,2-6,9,10 and a section property list of 2,3, the filter will include only those members in the specified list that use section properties 2 or 3. The more check boxes you enable and corresponding items you specify, the more you limit the nodes, members or plates that are included in the filter. You can define up to 200 different filters and scroll between them in the form by changing the "Filter" numeric field.

The Include/Exclude buttons simply reverse the effect of the items in the filter line. For example, if you specify a node list of 2-5,9,13 and select "Include" then those nodes will be included in the filter. However, if you select "Exclude" then all the nodes except 2-5,9 and 13 will be included in the filter.

You can use the "Select" buttons in the "Nodes", "Members" and "Plates" lines to graphically select or edit node, member and plate lists rather than having to type them in manually. You can also use the "Select" buttons to graphically add to or modify filters that were previously defined using other than node, member or plate lists.

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Filters can also be based on lists of steel design members or connections, or steel member design results. The "X-axis", "Y-axis", and "Z-axis" fields allow you to specify minimum and maximum limits for one or more axis directions. You can enter ranges into the fields manually or select them graphically by clicking their "Select" button. Any parts of the frame which fall outside of these limits are excluded from the filter. The "Grey out members not in filter" checkbox allows you to show in a faint line or completely hide any members that are not included in the active filter. To select and activate a filter Click the "Filters" toolbar combo box selection.

and make your

Scrolling through the filters can be most conveniently done using the keyboard Ctrl+Page keys as described in Shortcuts.

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Graphical Input

Views This tool is replicated in the renderer and in the traditional graphics window. This tool lets you save everything about the current graphics display including its load case selections, filter selection, viewpoint, and any diagrams or node, member or plate properties that might be shown. The renderer version This is fully explained in View manager.

The traditional graphics window version To save the current display as a view or to manage the currently saved views, click the toolbar button or select "Views" from the View menu or the floating menu. You must then select "Save the Current View" from the floating menu that appears.

To save the current view, just click the combo box in the above form, select a view number and then type in the view’s name. You can overwrite previously saved views or you can select and name an unused view. You can save up to 100 different views. To manage (delete, renumber or rename) previously saved views, click the toolbar button or select "Views" from the View menu or the floating menu. You must then select "Manage the Saved Views" from the floating menu that appears.

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To delete, renumber or rename any of the previously saved views, click the desired view in the datasheet shown above and then delete or edit it as required. To select and activate a view, click the "Views" toolbar combo box and make your selection. Scrolling through the saved views can be most conveniently done using the keyboard Shift+Ctrl+Page keys as described in Shortcuts.

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Graphical Input

Viewpoint This tool is replicated in the renderer and in the traditional graphics window. This tool allows you to rotate your viewpoint around the structure. You can obtain an elevation from any side, a plan view or a view from any other position. In the renderer you can also switch between orthographic and perspective viewing modes. The renderer version You can zoom, pan or rotate your model via the mouse scrollwheel or by dragging it around using the left or right mouse buttons as shown below.

Rotate the viewpoint by holding down the left mouse button while moving the mouse. An alternative to rotating the model by dragging it around directly is to drag the view selector around. You can also click one of the view selector faces, edges or corners to go straight to a specific viewpoint. If you click on the small square attached to the front face it will take you to the 30,10 viewpoint.

The traditional graphics window version Changing the viewpoint can be most conveniently done using the mousewheel or keyboard arrow keys as described in "Shortcuts". For example, while viewing the structure graphically, just hold down the H key and use the mousewheel to rotate

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SPACE GASS 12 User Manual your viewpoint horizontally, or hold down the V key and use the mousewheel to rotate your viewpoint vertically. Alternatively, you can rotate your viewpoint by clicking the toolbar button or selecting "Viewpoint" from the View menu or the floating menu. The current viewpoint setting is displayed near the top-right corner of the graphics display area together with a small set of axes. You can watch the axes move as you change the viewpoint or, by activating real-time structure rotation, you can also watch the entire structure rotating as you change the viewpoint. There are a number of ways to change the viewpoint as explained as follows. 1. Clicking the arrow buttons above the side toolbar buttons (as follows) allows you to change the viewpoint quickly without having to first click on any other buttons. After reaching the desired viewpoint, pick a point anywhere inside the graphics display area to cause a redraw at the new viewpoint.

2. Choosing "Viewpoint-View real-time" from the View menu or the floating menu allows you to rotate the entire structure on the screen using the keyboard arrow keys. After reaching the desired viewpoint, pick a point anywhere inside the graphics display area to cause a redraw at the new viewpoint. 3. Choosing one of the "View front/View plan/View (30,10)/etc." items after clicking the "Viewpoint" toolbar button or from the "Viewpoint" item of the View menu or the floating menu causes the structure to be immediately redrawn at the new viewpoint. The "(30,10)" item corresponds to a horizontal angle of 30 and a vertical angle of 10. It is a useful viewpoint for 3D structures. 4. Choosing "Select" after clicking the "Viewpoint" toolbar button or from the "Viewpoint" item of the View menu or the floating menu causes the following form to appear.

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Graphical Input

You can change the viewpoint by editing the "Horizontal angle" and "Vertical angle" text boxes directly, or you can click on one of the arrow buttons at the bottom-left corner of the form. When using the arrow buttons, the amount by which the viewpoint changes can be controlled by setting the value in the "Angle increment" field. Alternatively, you can click on one of the seven plane buttons which take you immediately to a front, plan, left, (30,10), right, back or bottom viewpoint. SPACE GASS normally assumes that the global Y-axis is vertical when displaying the structure graphically, however the viewpoint form allows you to change the vertical axis to one of the other global axes.

The viewpoint settings (including the "Vertical axis" setting) only affect the graphics display. They don’t affect the local axis definitions, the steel design top flange definitions, or the analysis and design modules in any way.

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View manager In the renderer you can save the current view for later recall by right-clicking anywhere in the graphics area and then selecting "Save View" from the menu that appears. The view is saved as soon as you enter a name and click Ok in the form shown below.

The view manager (located in a panel on the right side of the renderer) lists all of the saved views. You can recall a view by simply clicking on it in the View Manager panel.

Note that the View Manager panel can be pinned open by clicking the button at the top of the panel so that it changes to . If you click it again, it changes to , indicating that the panel is not pinned and will slide closed as soon as you move away from it. Note also that you can drag the View Manager panel away from the side of the renderer and dock it to another location or you can just place it anywhere on your screen.

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Graphical Input

Notes Notes can be attached to nodes, members or plates, or simply placed anywhere on or near the model.

To add a note you can right-click anywhere in space or on a node, member or plate and then select "Add Note" to bring up the following form. The form lets you set the note's colors, leader length and location. When you click Ok the note appears in the renderer. Notes are saved with the job and stay with the model unless you delete them.

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In order to move, edit or delete a note, you must open the Notes Editor via the button in the bottom toolbar of the renderer as shown below. Notes can also be hidden en-masse via the "Show notes" option in the renderer's View menu.

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Graphical Input

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Measurements and dimensions The Measurement and Dimensioning tool in the renderer lets you measure distances and angles between points that you select graphically or lengths and orientations of members. You can also add dimensions to your model. Measure Right-click on a member, on a node or on any point away from your model and then select "Measure/Dimension" in the menu that appears. Alternatively, you can select two nodes or two other points, right-click and then select "Measure/Dimension" or you can simply click the button in the toolbar at the bottom of the renderer. The form that appears below shows the actual distance (or member length), the projected distances and the angles between the nodes, member ends or points selected. You can then continue to click other nodes, members or points on or around your model and see the data updated in the form.

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Graphical Input

Dimension At any time while using the Measure tool, you can click the "Add Dimension' button in the form to add a dimension to your model. If the dimension is not exactly how you want it, you can experiment with the settings in the "Dimension" part of the form to adjust it as required. Dimensions can be updated or deleted by simply selecting them, right-clicking and then selecting "Edit Dimension" or "Delete" from the menu that appears.

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Don't forget that if you want to select a point that is not on a node or a member but is lined up with one, you can simply hover over the node or member for a second until you hear the "lock on" pop sound and you can then move away and still stay lined up. This is handy if you want to add dimension lines some distance away from a point such as with the "12m" dimension in the model shown above. In this case you could click the node at the bottom of the column, hover over the apex node until it "locks on" and then move back in line with the column staying lined up with the apex node before clicking the second dimension point (see below). For more information, see Attachment and alignment methods.

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Graphical Input

Gridlines Gridlines can be added to your model at any stage of its development. As well as providing a visual reference, they can also be attached to when you are drawing or editing your model.

Gridlines can be created, edited or turned on or off via the button in the renderer's bottom toolbar. You can simply enter the desired gridline tags, positions and elevations into the appropriate tables of the form shown below. By entering more than one line of data in the Elevations table you can have multiple sets of gridlines at different elevations.

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Gridlines can also be generated by clicking "Auto Generate Gridlines" buttons via the form shown below.

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Graphical Input

Textures Textures can be applied to members and plates depending on their material. For example, if the material name starts with "Steel" then the steel texture is used, or if it starts with "Conc" then the concrete texture is used. Textures are also available for aluminium, timber and brickwork. They can then be turned on or off via the button in the toolbar at the bottom of the renderer.

Textures off

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Textures on

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Graphical Input

Transparency When in rendered mode, the appearance of members and plates can be adjusted to be fully or partially transparent by clicking the the renderer.

in the toolbar at the bottom of

The transparency can then be adjusted by sliding the controls for members and or plates followed by clicking anywhere in the graphics area of the renderer.

The following before and after images show how members and plates can be made to look transparent.

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Graphical Input

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Repeat last command This tool is only available in the traditional graphics window. By pressing the keyboard spacebar, you can repeat the last command. This can be useful in situations where you need to repeat an operation a number of times.

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Analysis Analysis SPACE GASS uses the well documented stiffness method combined with a wavefront equation solver to model the elastic behaviour of structures. It is capable of performing five types of analysis, as follows.     

Linear (1st order) static analysis Non-linear (2nd order) static analysis Dynamic frequency analysis Dynamic response analysis Buckling analysis

The SPACE GASS analysis modules can accurately deal with semi-rigid joints, elastic supports, master-slave constraints, offsets, tension/compression-only members, and cable members (static and buckling analysis only). Although the wavefront method is not highly sensitive to badly numbered structures, a wavefront optimizer which automatically minimizes the frontwidth is also available with SPACE GASS. The wavefront optimizer means that both the node, member and plate numbering sequences are incidental to the program. SPACE GASS has been dimensioned dynamically. This means that during the analysis phase SPACE GASS automatically adjusts its memory requirements according to the size of the job. If the available memory in your computer is enough to solve the structure entirely in memory then the analysis phase will be extremely fast. If you run out of memory during an analysis then some of the analysis data will be automatically written to disk and the analysis phase will not be quite as fast. You should aim to have as much of the data as possible held in memory during the analysis by minimizing the frontwidth or by increasing the memory capacity of your computer.

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Static analysis The SPACE GASS static analysis module is capable of performing linear or nonlinear analyses. Furthermore, you can analyse some load cases linearly and others non-linearly in the same model. For non-linear analysis, SPACE GASS offers a choice of small, finite or large displacement theories in its non-linear static analysis solver. For cable members, SPACE GASS always uses a large displacement theory that has been designed to cope with the highly non-linear behaviour and large deflections that occur within cables (see also Cable members). For structures that contain both cables and non-cable members, it is important to note that while the large local cable deflections are allowed for in the analysis, the non-cable parts of the structure are still analysed using small displacement theory. The plates in SPACE GASS are linear elements only and therefore no P- or P- effects are considered for them during a non-linear analysis. Although a SPACE GASS non-linear static analysis includes simple buckling checks on individual members and on the frame as a whole, a full buckling analysis is usually required in addition to the static analysis. If the buckling capacity of the frame has been exceeded then the static analysis results are invalid and should not used!

If the static analysis results are to be used for a steel design to AISC-LRFD, Eurocode 3, AS4100 or NZS3404, the load cases used in the strength design must be analysed non-linearly unless you know that the second order effects are negligible. The non-linear static analysis facility available with SPACE GASS considers geometric non-linearities rather than material non-linearities. Material non-linearities occur as a result of the non-linear stress-strain relationship of most materials. This effect becomes more significant as the material reaches its yield point and the stress-strain curve flattens out. SPACE GASS does not consider material non-linearities because they are relatively insignificant in comparison with geometric non-linearities and because their effect only becomes noticeable when the material is highly stressed.

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Analysis

There are many types of geometric non-linearities, some of which can be significant and many of which are relatively insignificant. The most important geometric non-linearities are:     

P- effect P- effect Axial shortening effect Tension/compression-only effect Catenary cable effect

Some sources refer to the additional effects of shear deformations and rigid end gussets as being geometric non-linearities also. While SPACE GASS fully considers these additional effects during the analysis phase, it does not consider them to be non-linearities because they can be solved directly in one analysis and do not require an iterative procedure.

Because the plates in SPACE GASS are linear elements, no P- or P- effects are considered for them during a non-linear analysis.

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Displacements, actions and reactions During the static analysis phase, there are three basic groups of data that have to be calculated. They are node displacements, member and plate actions (forces and moments) and support reactions. Node displacements Node displacements are calculated for each load case being analysed and for every unrestrained degree of freedom in the structure. Each node may translate along or rotate about any or all of the three global axis directions. Restrained (fixed or deleted) degrees of freedom are automatically assigned displacements of zero except for those nodes that have prescribed displacements specified. In such cases those nodes are assigned the prescribed displacement only for the particular load case in which they were specified. Member actions There are twelve forces and moments that can be calculated for each member. Each end of a member is subjected to an axial force, a torsion, bending moments about its y and z axes and shear forces along its y and z axes. The program is also capable of calculating forces and moments at user defined intermediate points along members. These intermediate values, however are not calculated during the analysis phase. Instead they are calculated as required when the output report is produced. For more information, refer to Sign conventions. Plate actions Three forces and three moments are calculated for each plate node, making a total of 18 actions per triangular plate and 24 actions per quadrilateral plate. Two axial stresses, three shear stresses and three bending stresses are also calculated for each plate. These are later used to calculate the 17 different force, moment and stress values for each plate that can be shown graphically as colored contours or included in text reports. For more information, refer to Sign conventions.

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Analysis Reactions External node reactions are the forces and moments exerted by the structure on the supports. They are calculated only for restrained nodes and are referenced by the global axes system.

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P-D effect The P- effect occurs as a result of the ends of an axially loaded member moving laterally with respect to each other. A moment of P. is induced which alters the member’s equilibrium and causes the relative member end movement to change further.

P- effect

Unless the axial load P exceeds the member’s critical buckling load, a point of equilibrium eventually occurs such that the P- moment is balanced by moments applied by other members or restraints. The P- effect is not considered for plate elements.

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Analysis

P-d effect The P- effect occurs as a result of lateral curvature being induced in an axially loaded member. A parabolic moment distribution is induced along the length of the member which alters the member’s effective stiffness and causes the curvature to change further.

P- effect

Unless the axial load P exceeds the member’s critical buckling load, a point of equilibrium eventually occurs such that the P- moments are balanced by internal flexural resistance built up within the member. The P- effect is not considered for plate elements.

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Tension-only and compression-only effects While in tension, tension-only members act identically to normal members with axial, flexural, torsional and shear capacity. However, if they go into compression then they are automatically disabled and act as if they have been removed from the model. Similarly, compression-only members act identically to normal members unless they are disabled as a result of going into tension. Although the solution of tension-only or compression-only members requires an iterative analysis method, SPACE GASS puts it into a slightly different category to the other non-linear effects and makes it available in either a linear or a non-linear static analysis. Unlike the P- and P- effects, tension-only and compression-only effects result in an exact solution provided that convergence can be achieved. For tension/compression-only effects, convergence is sometimes difficult (if not impossible), especially if the frame is highly symmetrical. If convergence is not achieved after three iterations, SPACE GASS relaxes the tension/compression-only criteria slightly in an attempt to improve the chances of reaching convergence. During the first three iterations SPACE GASS disables tension-only members which have either end in compression. During iterations four and five it disables tension-only members which have the average of their end forces in compression. During the sixth and further iterations it disables tension-only members which have both ends in compression. A similar procedure is followed for compression-only members which have tensile forces at their ends. If tension/compression-only effects have been activated with "No reversal" then convergence is usually achieved after two or three iterations, even for highly symmetrical structures. This "No reversal" method is not usually recommended, however because it sometimes results in members being prematurely disabled and then not being able to be re-enabled in later iterations after the axial forces have been redistributed around the frame.

Tension/compression-only effects are ignored by the dynamic frequency analysis module. No tension-only or compression-only members are disabled in a dynamic frequency analysis, regardless of their axial force.

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Analysis ! IMPORTANT NOTE ! Tension-only members should not be used to model cables. See also Members.

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Cable members The analysis of cable members requires special treatment because of their pure axial capacity, large displacements and highly non-linear behaviour. Cable members never actually go into compression, they simply sag or change their shape so that they are in equilibrium at all times. They have no flexural, torsional or shear capacity, and resist lateral loads by tension alone. Cable loading Cable members can be loaded with UDLs, thermal loads, prestress loads and self weight. For "Local" or "Global projected" UDLs, the total load is equal to the load per unit length multiplied by the actual (for "Local") or projected (for "Global projected") distance between the end nodes. For "Global inclined" UDLs, the total load is equal to the load per unit length multiplied by the unstrained cable length. Cables must be loaded with at least one uniformly distributed load (self weight will do) in every load case they are analysed for. If there is no UDL on a cable, SPACE GASS will apply an artificial lateral UDL equal to one-tenth of the self-weight of the cable. While this adds a non-existent load to the model, it is not likely to affect the results significantly due to the small magnitude of the load. Note that the procedure of converting cables without UDLs to tension-only members in SPACE GASS 9.03 and earlier versions is no longer done. Restraining nodes connected to cables Cable members have zero moment capacity and must be assumed to be pin-ended even if the end fixities are input as FFFFFF. This would normally cause rotational instabilities in the nodes that are connected only to cables, however SPACE GASS recognises this and automatically restrains these rotations if instabilities would occur. Cable convergence Convergence is often a problem for structures which contain cables because of their large deflections and highly non-linear behaviour. There are four recognized methods for obtaining convergence. 1. One load step, many iterations, no damping. 2. One load step, many iterations, deflection related damping. 3. One load step, many iterations, damping with uniform relaxation. 4. Many load steps, one iteration per load step, no damping.

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Analysis All four methods give the same results for the same final convergence. Methods 1 and 2 are generally the fastest but they don’t achieve convergence in all structures, especially flexible structures. Methods 3 and 4 are more likely to achieve convergence but sometimes require more iterations. For methods 3 and 4, the number of iterations required is pre-defined by the number of relaxation steps or load steps that you specify at the start of the analysis. For each method, but methods 3 and 4 in particular, it is generally apparent after only a few iterations whether convergence is going to be achieved or not. If the convergence level is not steadily creeping upwards or has not reached about 60% or 70% by 5 or 6 iterations then it is unlikely that convergence will be achieved. If this happens, it is generally best to stop the analysis and then start it again with a different method, or change the damping, or increase the number of load steps. For example, using method 4, it is quite feasible that 50 load steps will converge where 40 load steps will not. If you lower the convergence accuracy, the analysis may not converge sufficiently and you risk getting incorrect results. It is particularly important that you don’t lower the convergence accuracy for highly non-linear structures such as those that contain cables. Cable prestress The prestress load you apply to a cable is not likely to be the final axial force in the cable at the end of the analysis. This is because the axial force changes as the cable stretches or sags as its end nodes move. If you wish to achieve a particular axial force at the end of the analysis then a trial and error process is required. This involves setting an initial prestress force, performing the analysis, checking the final axial force, adjusting the prestress and repeating the process until the desired axial force is achieved. This is a common requirement in post-tensioned concrete applications where the tendons are jacked to a known tension. In some instances, you may wish to apply a prestress load to a cable member instead of specifying a non-zero unstrained cable length. The prestress load P that is equivalent to an unstrained cable length L is given by the equation:

where

D = chord length,

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SPACE GASS 12 User Manual A = cross sectional area, E = Young’s modulus of elasticity. ! IMPORTANT NOTE ! If cable members exist in your structure, it is imperative that you specify them as "Cable" members in your SPACE GASS model. If you try to model them as "Normal" or "Tension-only" members, the results will be incorrect. See also Members. See also Thermal loads.

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Analysis

Non-linear analysis procedure The procedure that SPACE GASS adopts to perform a non-linear static analysis is as follows. 1. An initial linear static analysis is performed. 2. For each element in each load case, a modified stiffness matrix is assembled. For non-cable members, the modified stiffness is based on the deformation of the structure and the member axial forces calculated in the previous analysis iteration. The modifications to the stiffness matrix are in accordance with the theory presented by Ghali and Neville (2) for small displacement theory or the theory presented by Hancock (24) for finite and large displacement theory. They involve changes to the axial and flexural stiffness terms, taking into account P- P- and axial shortening effects (if activated). For cable members, the modified stiffness is based on the unstrained cable length, the cable lateral loads and the deflected position of the cable ends calculated in the previous analysis iteration. For plate elements, the stiffness matrix is unchanged. 3. If P- effects are turned on with finite or large displacement theory, the non-cable member fixed end actions are adjusted for the deformation of the structure. 4. If P- effects are turned on, the non-cable member fixed end actions are adjusted for the change in flexural stiffness of the member. 5. The frame is re-analysed with the modified member stiffness matrices. In this and later analysis iterations, each load case must be solved separately because the structure stiffness matrix is now different for each load case. This can take considerably longer than the initial linear analysis, especially if there are numerous load cases. 6. The results of the latest analysis are compared with the previous analysis and the level of convergence is displayed on the screen. If the level of convergence has reached the requested convergence accuracy then the

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SPACE GASS 12 User Manual results have converged and the analysis terminates. If not, steps 2 and 3 are repeated for the unconverged load cases until a solution is reached. If some load cases have still not converged after the specified number of iterations per load step then the program pauses and asks if further iterations are required. If no further iterations are requested, the analysis terminates and the results for the converged load cases only are saved.

Because the plates in SPACE GASS are linear elements, no P- or P- effects are considered for them during a non-linear analysis.

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Analysis

Static analysis buckling Although a SPACE GASS non-linear static analysis does not perform a full buckling analysis, it does include some buckling checks as described below. For details of the capabilities of a full buckling analysis, refer to Buckling analysis. 1.

The SPACE GASS non-linear static analysis includes a simple buckling check on individual members that is intended to alert you if a member is being removed from the model due to its Euler buckling load being exceeded. However, it is not a full buckling check that considers groups of members or the structure as a whole. A common misconception appears to be that if the static analysis passes this simple single member buckling check then buckling is not a problem. Another misconception is that if the simple buckling check fails, you can just subdivide the buckled member until the error goes away and everything will be Ok. Clearly, this doesn't fix the problem, it just transfers the buckling from a single member mode to a multi-member mode that is no longer detected by the single member buckling check. The only way to be sure that buckling is not a problem is to perform a full buckling analysis.

2.

The SPACE GASS non-linear static analysis also includes a frame buckling check that simply alerts you if the structure's buckling capacity has been exceeded. This will allow you to determine if the static analysis results are reliable or not, and nothing more. It will not calculate member effective lengths or the buckling load factor, and hence will not be able to alert you if buckling is close to happening. Consequently, a full buckling analysis will still be required for most structures.

It is very important to note that the results of a static analysis will be incorrect if the structure's buckling capacity has been exceeded, and hence one of the key roles of a buckling analysis is to ratify the static analysis results. Although most practical structures do not come close to reaching their buckling load, unless you know that your frame has not reached its buckling load, you should perform a buckling analysis.

Because the plates in SPACE GASS are linear elements, they will not buckle regardless of the load applied. See also Buckling analysis.

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The wavefront optimizer The SPACE GASS wavefront optimizer temporarily re-organises the structure during the analysis phase to achieve close to the smallest possible frontwidth with the fastest possible analysis time. The basic philosophy behind the optimizer is quite simple. It alters the order in which members and plates are loaded into the stiffness array by starting at one end of the structure and proceeding through it to the other end in one complete pass. Depending on the operating mode selected, the optimization can follow an irregular path, a straight line path or a circular path. The optimizer usually reduces the frontwidth to within 95% of the optimum, however some structures such as large cubes which do not have a well defined "long dimension" can reduce its efficiency to almost 60%. Large cubic structures therefore may require careful member and/or plate numbering if they produce excessively large frontwidths. If you have already numbered the members and plates to achieve the smallest possible frontwidth then the optimizer will of course not have much effect. If, however you have numbered the elements badly, the optimizer will probably have a dramatic effect. The most noticeable effect will be the smaller analysis time which is partly proportional to the frontwidth squared. You can control the direction along which the optimization proceeds by selecting the optimization mode at the start of the analysis. The various optimization mode settings are described in the following sections. Not activated If the optimizer is not activated, the members and plates are loaded into the stiffness array in the order that they are numbered. If they have been badly numbered and the structure is large then excessive analysis times may result. Auto mode SPACE GASS trials the "General" and various "Linear" modes and then uses the one that gives the smallest frontwidth. It doesn't add significant time to the analysis and is the recommended setting. General mode SPACE GASS starts at the lowest numbered member or plate and then loads all of the elements that are connected directly to it. It then takes each of the connected

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Analysis elements in turn and loads all of the elements that are connected to them. This process continues until all elements in the structure have been loaded. This mode results in very efficient frontwidths for most structures. Linear mode This mode instructs the optimizer to proceed through the structure in a straight line direction parallel to one of the global X, Y or Z axes or along a vector that you specify. After you have specified linear mode, you must also nominate the axis or vector along which optimization will proceed. This should generally be in the direction of the long dimension of the structure. Linear mode is ideally suited to long thin structures which have a well defined long dimension. The "long dimension" of a structure is not necessarily the dimension with the greatest length, rather it is defined such that if you make a cut through the structure at right angles to the long dimension at its widest point, you will cut through the least number of elements. In the truss in the following diagram, the most efficient direction for the optimizer to proceed is horizontally. This is because a cut at right angles to the horizontal cuts through only four members.

Horizontal optimization

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Vertical optimization

In the 2D multi-storey frame above, the most efficient direction for linear optimization is vertical even though the frame height is less than the frame width. Circular mode This mode instructs the optimizer to proceed through the structure around an arc with the axis of rotation parallel to one of the global X, Y or Z axes. After you have specified circular mode, you must also nominate the axis about which optimization will proceed, followed by the coordinates for the centre of rotation. Circular mode is ideally suited to curved structures such as the circular frame shown following. Structures which are not perfectly circular but which have a general shape which is arranged around a central point can also be optimized very efficiently using circular mode. The centre of rotation should generally be near the centre of the structure, however this is not absolutely essential.

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Analysis

Circular optimization

Circular mode can also be used to great advantage with structures that require linear optimization in two directions. A three dimensional multi-storey frame for example would probably require its primary optimization direction to be vertical. As the optimizer reached each floor, however a secondary horizontal direction would also need to be specified otherwise it would not know in which direction to go along the floor. Without a secondary direction, the optimizer would simply have to load the floor elements in the order of their numbering and this could result in an unnecessarily large frontwidth if the elements were badly numbered. It is not possible to specify a primary and secondary direction with the optimizer in linear mode, however it is possible to do this in circular mode by having the centre of rotation a large distance away from the structure. Using circular mode in this way is very similar to linear mode except that as the optimizer progresses across (or up) the structure, the angle of attack also changes slightly as it moves around the arc.

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Bi-directional optimization

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Analysis Consider for example the three dimensional multi-storey frame shown above. The primary optimization direction is vertical and the secondary direction for each floor is to the left. By using circular mode and positioning the centre of rotation at a large distance away from the frame as shown in the following diagram, the desired result can be achieved.

Bi-directional optimization using circular mode

As the optimization line progresses up the structure, it reaches the right hand side of each floor before the left hand side. Thus, the structure as a whole is optimized from bottom to top and each floor is optimized from right to left. Note that this method of optimization is usually the best way to deal with large cubic shaped structures. If you are not sure which optimizer mode to use for a particular structure, it is recommended that you experiment with various modes to see how small a frontwidth can be achieved. You can do this by running the analysis and then terminating it by pressing ESC or the right mouse button after the frontwidth has been calculated and displayed on the screen. Once you have found the most efficient mode, you can simply let the analysis continue to the end as normal.

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The wavefront analysis method Conventional structural analysis programs utilizing the stiffness method generally use a bandwidth equation solver which requires that nodes be numbered correctly to ensure the smallest possible bandwidth. The wavefront method, however requires that the members and plates be numbered correctly to ensure the smallest possible frontwidth. The optimum wavefront numbering sequence, however is quite logical and is not sensitive to adding more nodes, members and plates at a later stage which are out of sequence. This can be quite a problem with the bandwidth method. For most structures, the element numbering sequence doesn’t matter because the frontwidth capacity of SPACE GASS is quite large. Large structures, however can be made to analyse faster by optimizing the frontwidth. The displacements calculation time is roughly proportional to the square of the frontwidth. A wavefront optimizer is available with SPACE GASS which internally re-orders the stiffness matrix and which generally reduces the frontwidth to within 95% of the optimum. The optimizer adds only a few seconds to the analysis time and gives you the freedom of not having to concern yourself with element numbering sequences even for the largest structures. For those of you who are interested in the wavefront solution method, the following sections should give you an insight into the inner workings of the SPACE GASS analysis module.

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Analysis

A quick frontwidth calculation method In order to minimize the frontwidth, members and plates should be numbered from side to side across the structure’s shortest dimension while gradually proceeding up the length of the structure. The numbering should proceed up the entire length of the structure in one pass. A tall multistorey building for example would have the ground floor columns numbered first, followed by first floor beams, first floor columns, second floor beams, second floor columns etc., right up to the top. A quick frontwidth calculation can be done as follows. 1.

This procedure assumes that the element numbering sequence proceeds generally from one end of the structure to the other in a single pass as described in the paragraph above.

2.

Make an imaginary cut through the structure at its widest point and at right angles to the general direction of element numbering. For example, the multistorey frame described above would have a horizontal cut at any one of its levels.

3.

On one side of the cut only, count the number of nodes that are connected to elements that have been cut.

4.

Add 1 to the number of nodes in step 3 above and multiply by the degrees of freedom (DOF) per node. For 3D frames this will generally be 6 DOF per node.

5.

Subtract the number of restrained DOF (ie. the restraints applied to the nodes counted in step 3).

The final figure is the structure frontwidth. It is generally not necessary for you to know any more about the wavefront method than has been described above, however for those of you wishing to know more, a detailed explanation of the wavefront analysis method follows.

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The wavefront method in more detail Both the bandwidth and wavefront methods are primarily concerned with the assemblage and solution of a very large structure stiffness array. This array equates node displacements to externally applied loads as follows. [P]=[K][D], where

[P] = Load array [K] = Structure stiffness array [D] = Node displacement array

[P] and [K] are fully defined while [D] is the unknown. The wavefront method is different to the bandwidth method in that the structure stiffness array is assembled in order of element numbering rather than node numbering, and a much smaller portion of the array is required in memory at any one time. In the wavefront method, the program loads each element into the stiffness array in order of the element numbering sequence. The nodes associated with each element have stiffness equations that occupy certain rows and columns in the array. This loading process continues until one or more nodes have been fully assembled. A node is said to be fully assembled when all elements connected to it have been loaded into the array. At this point the equations associated with that node can be solved and removed, thus leaving space in the array for other nodes. Further elements are then loaded and their nodes take the place of nodes that have previously been solved and removed. More node equations are eliminated and the whole process continues until the entire structure has been fed in and the stiffness array emptied. The frontwidth is equal to the largest number of node equations that occupied the stiffness array at one time.

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Analysis

Running a static analysis You can run a static analysis by selecting "Linear Static Analysis" or "Non-linear Static Analysis" from the Analysis menu or you can change from linear to nonlinear or vice-versa using the Type analysis parameter in the form shown below.

Load case list If you want to analyse all load cases then this field can be left blank, otherwise you should type in a list of load cases (separated by commas or dashes) that you want analysed. For the fastest analysis time you should generally analyse only the load cases that can occur in reality. For example, there is no point in analysing a live load case on its own because it can't occur in real life without being combined with dead load. This means that you should generally analyse just the combination load cases and not the primary load cases that the combinations are made from. It is sometimes also possible to achieve time savings by analysing non-linearly only those load cases that cause 2nd order effects, and analysing all of the other load cases linearly. This would have to be done in two runs, however because a

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SPACE GASS 12 User Manual non-linear analysis can take considerably longer than a linear analysis (especially if there are a large number of load cases), it is often worthwhile. Further time savings can be made by not analysing linear combination load cases. "Linear combination load cases" are combinations that have all of their primary load cases analysed linearly. Results for non-analysed linear combinations are assembled from the primary load cases at the time a report or graphics output is generated. If a combination load case has one or more of its primary load cases analysed non-linearly or if the structure contains tension-only or compression-only members then the combination will have to be analysed in order to obtain results for it. When specifying the load case list, you can either list them directly, or you can click the button to display and select from a list of the load cases currently in the job as shown below.

Tension/Comp-only effects Tension/compression-only effects can be "fully operational", "operational with no reversal" or "fully de-activated". "Fully operational" means that tension-only or compression-only members which have been disabled during the analysis are able to be re-enabled if their axial force is reversed.

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Analysis

"Operational with no reversal" means that once they have been disabled they cannot be re-enabled even if their axial force has reversed. No reversal is useful if the fully operational analysis will not converge, however you should check the results and, if required, manually disable some tens/comp-only members and then re-analyse. No reversal normally applies from the first iteration onwards, however you also have the option of activating it after a specified number of iterations. This means that the analysis will initially proceed with tension/compression-only effects fully activated and, if convergence hasn’t been achieved after a specified number iterations, it will change to "no reversal" mode. "Fully de-activated" means that they are treated as normal members, able to take tension and compression. See also Tension-only and compression-only effects. Cable damping factor This allows you to apply damping to the cable connected nodes. It does this by multiplying the stiffness terms of the unrestrained cable-only node degrees of freedom by the factor:

where Ratio depends on the damping relaxation and Damping is the cable damping factor. See also Cable members. Damping relaxation steps If cable damping is used, it must be relaxed as the solution proceeds so that at convergence there is no damping at all. Setting the damping relaxation steps to zero causes the damping to be relaxed in direct proportion to the change in deflection between the current and previous iterations. As convergence approaches 100%, the change in deflections approaches zero and hence the damping approaches zero.

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SPACE GASS 12 User Manual Alternatively, setting the damping relaxation steps to a finite value causes the damping to be relaxed in uniform steps down to zero. If this method is used, the analysis keeps iterating until the damping is fully relaxed, regardless of whether convergence has been achieved earlier or not. See also Cable members. Number of load steps This allows you to apply the load gradually in a number of small load steps. If you specify a single load step then all of the load is applied in the first iteration (this is how the program worked in all previous versions). If cable damping is also being used, the damping relaxation process begins anew for each load step. See also Cable members. Iterations per load step This parameter allows you to specify the maximum number of iterations that will occur in a load step before the program begins prompting you for extra iterations. A special case occurs if you specify just one iteration per load step, in which case the program proceeds to the next load step after one iteration regardless of whether convergence has been achieved or not.

The analysis will finish if the convergence accuracy is satisfied, even if the number of iterations per load step hasn’t been completed. Convergence accuracy (%) The convergence accuracy is only applicable for non-linear analyses. After each iteration, SPACE GASS compares the results of the latest analysis with the results of the previous analysis. If the comparison shows that the level of convergence has reached or exceeded the specified convergence accuracy then the analysis is assumed to have converged. If you lower the convergence accuracy, the analysis may not converge sufficiently and you risk getting incorrect results. It is particularly important that you don’t lower the convergence accuracy for highly non-linear structures such as those that contain cables.

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Analysis Retain results of other load cases If you have specified that not all load cases are to be analysed and, if results already exist for some of the non-specified load cases, you can choose to retain them or have them deleted. Show messages from single member buckling check During a non-linear analysis, SPACE GASS performs a simple Euler buckling check on each member individually (regardless of whether you have the buckling analysis module or not). If the buckling check fails then the member is disabled for the remainder of the analysis. If you select the "Show messages from single member buckling check" check box then a message is displayed whenever a member fails the simple buckling check. For more information, refer to Static analysis buckling. Perform frame buckling check SPACE GASS can optionally perform a frame buckling check during a non-linear analysis that simply alerts you if the structure's buckling capacity has been exceeded. If this happens, you cannot use the results of the static analysis because they will most likely be invalid and you should run a full buckling analysis to get the buckling load factor and find out where the buckling is occurring. For more information, refer to Static analysis buckling and Buckling analysis. Check for non-existent load cases If you have defined combination load cases that contain other load cases which don’t yet exist, this option will detect and report them. It is optional because some users prefer to have a standard set of combination load cases that contain primary load cases which are just ignored during the analysis if they don’t exist. Stabilize unrestrained nodes Nodes that are free to rotate or translate in one or more directions without resistance from interconnecting members, plates, restraints or constraints can be automatically restrained during the analysis so that instabilities don’t occur. For example, if a node was connected to a number of members, all of which were pin-ended, a rotational instability would normally result due to the unrestrained rotation of the node. However, the stabilize option would apply a temporary rotational restraint to the node during the analysis, preventing an instability. Although this solves many instabilities, it doesn’t fix them all, and the prevention of non-trivial instabilities is still dependent on good modelling practice.

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SPACE GASS 12 User Manual Rotate local loads with member chord rotation If this option is ticked then after the first analysis iteration any local member loads will be rotated with the chord rotation of the members to which they are applied. It can be used to ensure that wind loads or hydrostatic loads remain normal to the member direction as the model deforms. This option is only enabled with finite or large displacement theory in a non-linear analysis. Type Even though you have already chosen "Linear" or "Non-linear" from the Analysis menu, this pair of radio buttons allows you to change your mind without having to exit the form. A linear analysis generally involves only one iteration and does not adjust the stiffness of the structure based on its deformation. It is suitable for simple beams or fully braced frames, but not for sway frames or flexible structures in which non-linear effects are significant. A non-linear analysis involves an iterative procedure that updates the stiffness of the structure after each iteration and gives more realistic results than a linear analysis. Solver The "Paradise" solver is a new parallel multi-core sparse solver that fully utilizes the multiple cores in a modern computer's CPU. All of the available cores are run in parallel to get the maximum possible analysis speed. It also takes full advantage of the sparseness of the structural matrix during the solution to minimize memory requirements and further increase the speed. The Paradise solver is the recommended setting for all static analyses. The "Wavefront" solver also takes into account the sparseness of the matrix but doesn't run in multi-core mode. It is generally slower than the Paradise solver and can be used if the Paradise solver is unable to obtain a solution. The "Watcom" solver is the one used in pre-SPACE GASS 12 versions. It is considerably slower than the Paradise and Wavefront solvers and is therefore of limited use. All three solvers should yield virtually identical results. Theory Small displacement theory (based on Ghali and Neville (2)) is the default setting and is suitable for most structures in which the members aren't subjected to significant chord rotations (changes in direction of members). Small displacement theory results are output in the undeformed axes system. The finite and large displacement theories (based on Hancock (24)) take member chord rotations into

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Analysis account and base their equilibrium equations on the deformed geometry. Finite and large displacement theory results are output in the deformed axes system. Large displacement theory uses more exact methods than finite theory when adjusting the stiffness matrix to allow for the deformation of the structure, however for many structures they yield very similar results. Note that although the finite and large displacement theories can handle larger displacements, it is often harder to achieve convergence with them than with small displacement theory, especially when large displacements occur. Matrix The main stiffness matrix can be a secant matrix (relating the full loads to the total displacements) or a tangent matrix (relating the residual loads to incremental displacements). A tangent matrix generally reaches convergence in a smaller number of iterations than a secant matrix and is more suited to large displacements, however this is not always the case. They both yield similar results. Note that small displacement theory always uses a secant matrix. Residual loads are the imbalance between the applied loads and the internal frame forces at each node. Incremental displacements are the difference in displacements between the current and the previous iteration. The residual loads and the incremental displacements both approach zero as the solution approaches convergence. Note that if you use a secant matrix with finite or large displacement theory and full loading, the stiffness matrix is non-symmetrical. This means that during the analysis, the stiffness matrix uses up twice as much memory as it otherwise would and so it should be avoided if your model is large. Loading For a secant matrix, you can choose between full or residual loading (see above), whereas the tangent matrix always uses residual loading. They both yield similar results, but if convergence is a problem then it may be worth experimenting with this setting. Convergence Convergence can be based on deflections or residuals or both and is achieved when they approach zero. It is recommended to have them both selected.

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SPACE GASS 12 User Manual P-Delta (P- effect For a non-linear analysis, you are able to activate or de-activate P- effects. The P effect is usually the most significant 2nd order effect and is mandatory for nonlinear analyses which comply with most limit states design codes of practice. See also P-D effect. P-delta (P- effect For a non-linear analysis, you are able to activate or de-activate P- effects. The P effect is mandatory for non-linear analyses which comply with most limit states design codes of practice. See also P-d effect. Axial shortening effect For a non-linear analysis, you are able to activate or de-activate axial shortening effects. The axial shortening effect models the effect of the "shortening" of the distance between the ends of a member due to its curvature. Axial shortening induces extra tension in a member that has a significant curvature. It is turned off by default and generally has a minimal effect on the analysis results. Optimization method The wavefront optimizer can be de-activated or it can be operated in one of four modes as follows. 1. No optimization

2. Auto mode - SPACE GASS trials the "General" and various "Linear" modes and then uses the one that gives the smallest frontwidth. It doesn't add significant time to the analysis and is the recommended setting.

3. General mode - SPACE GASS determines the path along which optimization proceeds through the structure.

4. Linear mode - You select from the X, Y or Z axes or a vector along which optimization proceeds in a straight line through the structure.

5. Circular mode - You select either of the X, Y or Z axes about which optimization proceeds around an arc through the structure. See also The wavefront optimizer.

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Analysis

Optimization axis If you have selected "Linear" or "Circular" for the wavefront optimization mode then you must select the axis or vector along or about which optimization will proceed. See also The wavefront optimizer. Coordinates of optimization centre If you have selected "Circular" for the wavefront optimization mode then you must select the centre of rotation about which optimization will proceed. See also The wavefront optimizer.

When all of the information has been entered, the static analysis module calculates the displacements, forces, moments and reactions for each load case and then saves them ready for graphical or text report output. If you want to terminate the analysis before it is finished, just press ESC or the right mouse button. If you terminate the analysis in this way, the results for any load cases which have already converged are saved. This applies to non-linear analyses and to linear analyses with tension-only or compression-only members.

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Static analysis results At the end of the static analysis, a message stating whether the analysis was successful or not is displayed together with a number of possible warnings and errors. Refer to "Ill-conditioning and instabilities" for details of what to do if an illconditioning or instability message is displayed. Refer to "Static analysis buckling" for details of what to do if a frame buckling message is displayed. Displacements, forces, moments and stresses The displacements, forces, moments and stresses calculated during the static analysis can be included in a report. They can also be viewed graphically in diagrams superimposed over the undeformed frame as described in "View diagrams". For plate elements, contour diagrams can be displayed as described in "View plate contours". You can also query individual nodes, members or plates graphically to find their displacements, forces and moments as described in "Query analysis results".

For full details of the forces, moments and stresses in members and plates, refer to "Sign conventions". Bill of materials A bill of materials report showing quantities, lengths and masses of each type of component in the structure can be included in a report. It bundles members of the same type and length together and shows their individual and total lengths and masses. It also shows the total structure mass and centre of gravity location. Centre of gravity The SPACE GASS bill of materials report includes the coordinates of the structure centre of gravity.

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Analysis

Dynamic frequency analysis The SPACE GASS dynamic frequency analysis module is able to analyse multiple mass load cases consisting of self mass and/or user defined lumped masses in a single run. For each mass load case it calculates the natural frequency (eigenvalue), period and mode shape (eigenvector) for any user defined number of vibration modes. The natural frequencies, periods and mode shapes comprise the dynamic properties of the structure.

You must perform a dynamic frequency analysis before performing a dynamic response analysis.

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Modelling considerations The dynamic properties of a structure are dependent only on its geometric properties, stiffness and mass. The geometric properties and stiffness of the structure are determined automatically from the node coordinates, member connectivity and fixity, plate connectivity, node restraints, section properties and material properties. The structure mass is made up of self mass (applied as lumped masses on every node) and extra applied lumped masses. Self mass can be calculated automatically during the dynamic frequency analysis if requested, while any extra lumped masses must be pre-defined by the user. In most cases, lumped masses placed at nodes are an adequate means of defining the mass distribution throughout the structure. However, where the distribution of mass is critical, extra nodes may be required. For example, consider a vertical cantilevered structure (such as a pole or tower). In order to accurately determine the natural frequencies you must define the distribution of mass up the cantilever by adding intermediate nodes with masses applied to them. A similar situation applies with a continuous beam where the mode shapes between supports are important. As a general rule, extra intermediate nodes (with masses applied) should be added to members for which the mass is a significant part of the total mass of the structure. Structures with a small number of members are often affected in this way. Dynamic mode shape deflections are calculated and output at nodes only. Therefore, in order to get realistic looking mode shapes it is sometimes necessary to add intermediate nodes to some members, particularly if the deflected shapes of these members have significant curvature. If the local deflected shape of a member is of interest then the distribution of mass along it will also be important and the requirement for intermediate nodes will apply anyway.

The dynamic frequency analysis module cannot analyse structures that contain cable members.

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Analysis

Running a dynamic frequency analysis You can run a dynamic frequency analysis by selecting "Dynamic Frequency Analysis" from the Analysis menu. The dynamic frequency analysis is a linear analysis and hence cannot be used with models that contain cable members. Furthermore, it treats tension-only and compression-only members as normal members that can take tension and compression. Note that the requirement to save the stiffness matrix during an initial static analysis is no longer required for a dynamic frequency analysis.

Load case list If you want to analyse all load cases then this field can be left blank, otherwise you should type in a list of load cases (separated by commas or dashes) that you want analysed. When specifying the load case list, you can either list them directly, or you can button to display and select from a list of the load cases currently in click the the job as shown below.

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Note that only the load cases that contain lumped masses or self-weight are considered during a dynamic frequency analysis. Load cases that contain selfweight with other static loads and no lumped masses are not considered, however load cases that contain only self-weight are considered. Any static loads that exist in the dynamic load cases are ignored. Consider the following examples: Contents of load case Masses only Self-weight only Static loads only Masses + self-weight Masses + static Masses + self-weight + static Self-weight + static

Considered Yes Yes No Yes Yes (static loads ignored) Yes (static loads ignored) No

Self mass The self mass of the structure can be calculated automatically by SPACE GASS and included in the dynamic frequency analysis. This can be done either by adding self-weight to a load case that contains lumped masses or by combining lumped mass and self-weight load cases into a combination load case.

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Analysis Self mass is applied by calculating the mass of each member and then applying half of it as translational lumped masses to each of the member end nodes in each of the unrestrained X, Y and Z global axis directions. The mass of each plate is also calculated and applied to its perimeter nodes Self mass generation does not calculate rotational masses because of the large number of extra masses that would be calculated for a fairly insignificant improvement in results accuracy. If required, rotational self mass must be manually applied as rotational lumped masses. See also Lumped masses. See also Self-weight. Tolerance (Hz) The accuracy to which the dynamic natural frequencies will be calculated. For example, a tolerance of 0.001 means that the frequencies will be within +/- 0.001 of the exact value. The tolerance can also have a significant effect on the accuracy of the mode shapes. While the mode shapes are usually of secondary importance if only a dynamic frequency analysis is done, they are very important if the frequency analysis is followed by a dynamic response analysis. Inaccurate mode shapes from the frequency analysis can cause significant errors in the mass participation factors from the response analysis and its results in general. Even if a natural frequency is accurate to within 0.01Hz, its corresponding mode shape may not be accurate enough for a dynamic response analysis. If the "Extra iterations for mode shape accuracy" option is turned on (see below) then SPACE GASS will detect significantly incorrect mode shapes during the frequency analysis and will correct them automatically by doing more iterations. Small mode shape inaccuracies cannot be detected by the frequency analysis, however they sometimes make themselves evident in the response analysis by mass participation factors that exceed 100%. A warning is given if this occurs and you should repeat the frequency analysis using a smaller tolerance. If the results of the frequency analysis won’t be used in a response analysis then a tolerance of 0.01 is more than enough, however if a response analysis is to follow then a tolerance of 0.001 or less should be used.

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Each extra decimal place in the tolerance will increase the number of iterations per mode by 3 or 4. For example, a tolerance of 0.0001 will require 3 or 4 more iterations per mode than a tolerance of 0.001. Frequency upper limit (Hz) The upper limit above which the dynamic frequency analysis will no longer search for natural frequencies. Once this limit is reached, the analysis will stop, even if not all requested dynamic modes have been calculated. Frequency lower limit (Hz) The lower limit below which the dynamic frequency analysis will not search for natural frequencies. Dynamic modes The dynamic frequency analysis module calculates the mode shapes, natural frequencies and natural periods for the number of dynamic modes requested. It also sorts them into ascending frequency order. See also View diagrams. Frequency shift (Hz) The dynamic frequency analysis normally calculates natural frequencies starting from 0Hz and working upwards, however if a frequency shift is specified then the frequencies below the frequency shift value are skipped. For example, if your structure has natural frequencies of 1.2Hz, 3.2Hz, 6.7Hz, 10.2Hz, 15.3Hz and 16.1Hz but you are only interested in the frequencies above 10Hz, you could specify a frequency shift of 10Hz. This would skip the lower three modes (saving you considerable analysis time) and just calculate frequencies 10.2Hz, 15.3Hz and 16.1Hz. Retain results of other load cases If you have specified that not all load cases are to be analysed and, if results already exist for some of the non-specified load cases, you can choose to retain them or have them deleted. Check for non-existent load cases If you have defined combination load cases that contain other load cases that don’t yet exist, this option will detect and report them. It is optional because some users

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Analysis prefer to have a standard set of combination load cases that contain primary load cases which are just ignored during the analysis if they don’t exist. Stabilize unrestrained nodes Nodes that are free to rotate or translate in one or more directions without resistance from interconnecting members, plates, restraints or constraints can be automatically restrained during the analysis so that instabilities don’t occur. For example, if a node was connected to a number of members, all of which were pin-ended, a rotational instability would normally result due to the unrestrained rotation of the node. However, the stabilize option would apply a temporary rotational restraint to the node during the analysis, preventing an instability. Although this solves many instabilities, it doesn’t fix them all, and the prevention of non-trivial instabilities is still dependent on good modelling practice. Extra iterations for mode shape accuracy The dynamic frequency analysis is complete when the natural frequencies have reached the desired accuracy (as specified by the tolerance), however it is possible that at this point the dynamic mode shapes are not totally accurate. Mode shape accuracy can be achieved by turning on the "Extra iterations for mode shape accuracy" option, however if the dynamic mode shapes are only used as a visual aid to assess the vibration location and its shape then the extra iterations and analysis time involved may not be warranted. If, however, a dynamic response analysis is to be done based on the frequency analysis then the mode shapes are very important and it is imperative that the "Extra iterations for mode shape accuracy" option is turned on. Even with the extra iterations, in some cases the mode shapes may still not be accurate enough (as sometimes evidenced by a mass participation factor from the response analysis that exceeds 100%) and further accuracy can then only be achieved by using a smaller tolerance. Solver The "Paradise" solver is a new parallel multi-core sparse solver that fully utilizes the multiple cores in a modern computer's CPU. All of the available cores are run in parallel to get the maximum possible analysis speed. It also takes full advantage of the sparseness of the structural matrix during the solution to minimize memory requirements and further increase the speed. The Paradise solver is the recommended setting for all dynamic frequency analyses.

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SPACE GASS 12 User Manual The "Wavefront" solver also takes into account the sparseness of the matrix but doesn't run in multi-core mode. It is generally slower than the Paradise solver and can be used if the Paradise solver is unable to obtain a solution. The "Watcom" solver is the one used in pre-SPACE GASS 12 versions. It is considerably slower than the Paradise and Wavefront solvers and is therefore of limited use. All three solvers should yield virtually identical results. Optimization method The wavefront optimizer can be de-activated or it can be operated in one of four modes as follows. 1. No optimization

2. Auto mode - SPACE GASS trials the "General" and various "Linear" modes and then uses the one that gives the smallest frontwidth. It doesn't add significant time to the analysis and is the recommended setting.



5. Circular mode - You select either of the X, Y or Z axes about which optimization proceeds around an arc through the structure. See also The wavefront optimizer. Optimization axis If you have selected "Linear" or "Circular" for the wavefront optimization mode then you must select the axis or vector along or about which optimization will proceed. See also The wavefront optimizer.

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Analysis Coordinates of optimization centre If you have selected "Circular" for the wavefront optimization mode then you must select the centre of rotation about which optimization will proceed. See also The wavefront optimizer.

When all of the information has been entered, the dynamic frequency analysis module calculates the natural frequencies, periods and mode shapes for each load case and then saves them ready for graphical or text report output. If you want to terminate the analysis before it is finished, just press ESC or the right mouse button.

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Dynamic frequency analysis results The natural frequencies, periods and mode shapes calculated during the static analysis can be included in a report. They can also be viewed graphically in animated diagrams superimposed over the undeformed frame as described in "View dynamic mode shapes". Mode shape displacements are relative only. They define the mode shape, not its magnitude. You can’t compare the displacements of different mode shapes in an attempt to determine which mode will result in the largest displacements. The scale factor for the displacements of each mode shape is unique to that mode. The mode shapes in SPACE GASS are normalized. This means that the translations and rotations in a mode shape will have been adjusted such that each translation or rotation is divided by the absolute value of the largest translational displacement for the mode shape under consideration. This makes it easier for you to relate the displacement of a particular node to the maximum displacement within a mode shape. For example, a normalized displacement of 0.60 indicates that the node moves by an amount which is 60% of the maximum displacement in that particular mode shape. If you wish to use the dynamic frequency analysis results to perform an earthquake analysis, refer to "Dynamic response analysis".

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Analysis

Dynamic response analysis The SPACE GASS spectral module performs a dynamic response analysis of structures subjected to earthquake loads given in the form of acceleration response spectra. Its general approach means that the spectral module is not just restricted to earthquakes, but can calculate the maximum response of a structure subjected to any ground vibration provided that all supports are vibrating in phase (ie. the same response spectrum is applied at all supports simultaneously). The spectral module considers the vibration of the structure and identifies the maximum values that result from the vibration. Generally, the maximums at different points of the structure occur at different times during the dynamic event. Consequently, the spectral results do not represent an equilibrium state of the structure, rather an envelope of the maximums. Furthermore, because the earthquake action has no sign (ie. its accelerations are both positive and negative), the maximum values have no sign and hence the sign of the results is indeterminate. Usually, the results are dominated by one of the mode shapes which SPACE GASS can identify and apply its sign to the results. Alternatively, you can select which mode shape the sign should be taken from. The spectral module is not code specific, however for ease of use with the Australian and New Zealand loading codes, many of the analysis input parameters have alternative code specific input options. These options require you to simply select from tables taken from the code rather than having to type in numeric values. Future versions will include these input aids for other international codes also. The earthquake loads are provided in the form of curves called "acceleration response spectra" which graph acceleration versus period. Each spectral curve is derived from the time-history record of a ground vibration for a specific level of damping, and is not dependent in any way on the properties of the structure being analysed. Usually, for one earthquake, there are several spectral curves for different damping ratios (eg. 0%, 1%, 2%, 5% and 10% of the critical damping). In the design codes, the spectral curves are derived from a set of earthquake records which are smoothed and averaged. A spectral curve library containing some standard (unauthorised) curves is supplied with SPACE GASS. The built-in graphical spectral curve editor allows you to modify or create your own spectral curves as required. The acceleration values in a spectral curve are always specified in terms of g (acceleration due to gravity) units. Before being used in an analysis, SPACE GASS automatically multiplies them by

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SPACE GASS 12 User Manual the dimensionless spectral curve multiplier and by the appropriate value of g to yield acceleration units that are consistent with the currently selected units system. For an accurate spectral analysis, it is important that the spectral load cases have been defined correctly and that appropriate combinations of the spectral load cases have been specified. For more information, refer to "Spectral load data". The results of the spectral analysis include deflections, forces, moments and reactions that can be displayed graphically, printed, or used in a steel design in the same way as the results from a static analysis. It is also possible to combine spectral load cases with static load cases in combination load cases. Refer to "Dynamic response analysis results" for details and interpretation of the results of a dynamic response analysis.

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Analysis

Running a dynamic response analysis You can run a dynamic response analysis by selecting "Dynamic Response Analysis" from the Analysis menu.

Before a dynamic response analysis can proceed, you must have performed a dynamic frequency analysis.

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SPACE GASS 12 User Manual Spectral load case list Leave blank if you want to analyse all spectral load cases, otherwise enter the load cases (separate by commas/dashes) you want analysed. Retain results of other load cases Check this box if you want to keep the analysis results of previously analysed spectral load cases. Otherwise, if they are not being re-analysed in the current session, they will be discarded. Loading code This allows you to select the loading code to be used. If you choose an AS or NZS code, you should ensure that you have also selected spectral curves for that same code in your spectral load data. One major difference between the "General" loading code and the AS or NZS codes is that the spectral curve multiplier must be manually defined for General, whereas it can be calculated based on code specific factors for the AS or NZS codes. There are also a number of other AS and NZS specific factors applied internally during the dynamic response analysis. Limit state For NZS, you must choose between serviceability or ultimate limit states together with an appropriate ductility factor.

The selected ductility factor is only used if a non-NZS spectral curve is used in the spectral load data. If you have used a predefined NZS spectral curve then the ductility factor is derived from it. Auto scaling of base shear This is a code related parameter that instructs the program to scale the results so that the sum of the support reactions obtained from the response spectrum analysis is not less than a user defined proportion of the total static force (or a user defined percentage of the structure’s weight for the "General" code). Vertical direction The axis indicates the vertical direction of the structure. This should usually match the vertical axis setting in the Viewpoint form.

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Analysis Base shear factor (%) Controls the scaling of the results so that the sum of the support reactions resolved along the axis of the direction vector is not less than the total static force (resolved in the same direction) multiplied by the scaling factor. For example, if you select a scaling factor of 90% the total reaction vector will be not less than 90% of the total static force vector. Site factor An AS1170.4-1994 specific factor that allows you to nominate an appropriate soil profile. You can elect to have the site factor calculated for you or you can choose a "User Defined" structure type and then type in the site factor directly.

The site factor you select is only used if a non-AS1170.4-1994 spectral curve is used in the spectral load data. If you have used a predefined AS1170.4-1994 spectral curve then the site factor is derived from it. Site subsoil class An NZS specific factor that allows you to nominate an appropriate site subsoil class.

The site subsoil class you select is only used if a non-NZS spectral curve is used in the spectral load data. If you have used a predefined NZS spectral curve then the site subsoil class is derived from it. Horizontal base shear factor (%) A "General" loading code specific factor that controls the scaling of the results so that the sum of the support reactions resolved along the axis of the direction vector equals the weight of the structure (including applied lumped masses) multiplied by the horizontal base shear factor. It is used if the direction vector is predominantly horizontal. For example, if you select a horizontal base shear of 3% the total reaction vector must be equal to 3% of the weight of the structure. Vertical base shear factor (%) A "General" loading code specific factor that controls the scaling of the results so that the sum of the support reactions resolved along the axis of the direction vector equals the weight of the structure (including applied lumped masses) multiplied by the vertical base shear factor. It is used if the direction vector is predominantly vertical. For example, if you select a vertical base shear of 2% the total reaction vector must be equal to 2% of the weight of the structure.

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Sign of the results Because the results of a response spectrum analysis are a combination of a number of mode shapes, the final sign of the results has to be determined. Choosing "No sign" is of limited use and means that all deflections, forces, moments and reactions will be positive. Choosing "Auto Sign" means that the sign of the predominant mode shape will be applied to the results. Choosing "Select Mode" tells the program to extract the sign from a nominated mode shape. Spectral curve multiplier The spectral curve multiplier is used to control the scale of the spectral curve acceleration values. It can be typed in directly or, by clicking the button next to the spectral curve multiplier field, can be defined via various code specific factors. For AS1170.4, it is based on probability, hazard, structural ductility and performance factors. Alternatively, for NZS1170.5, it is based on hazard, return period, nearfault and structural performance factors. Each of the code specific factors can be typed in directly or calculated automatically based on descriptions of the structure location, structure importance and construction method. Mode combination method The results for spectral load cases that contain more than one mode shape are obtained by combining the results for each of the mode shapes. You can choose between:  SRSS - Square Root of the Sum of Squares The simplest and most commonly used mode combination method that works well for most situations. 

CQC - Complete Quadratic Combination Recommended when some of the mode shapes to be combined have natural frequencies that are close together.

Either method can be used regardless of the spectral curve damping factors.

When all of the information has been entered, the dynamic response analysis module performs its calculations for each load case and then saves them ready for graphical or text report output. If you want to terminate the analysis before it is finished, just press ESC or the right mouse button.

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Analysis

Dynamic response procedure For each spectral load case, the analysis module calculates: 1. 2. 3. 4. 5. 6. 7. 8.

Total static (earthquake) force in each global axis direction. Dominant period in each global axis direction. Mass participation factor for the dominant mode in each global axis direction. Total mass participation factor in each global axis direction. Total mass participation factor. The mode to be used for determining the sign of the results. Node displacements for each mode. Mass participation factor in the earthquake direction for each mode.

The following calculations are then performed: 1.

Forces, moments and reactions are calculated from the node displacements for each mode.

2.

Displacements, forces, moments and reactions for each mode are combined into a single set of values for all the modes combined. This is done using SRSS or CQC as specified by the user.

3.

If base shear scaling is requested, the displacements, forces, moments and reactions are then scaled by a factor so that the base shear is equal to the base shear factor times the total mass (for "General") or not less than the base shear factor times the total static force (for AS or NZS loading codes). Note that the base shear is simply the X, Y and Z reactions resolved into a vector in the direction of the earthquake. Similarly, the total static force is the X, Y and Z static forces resolved into a vector in the direction of the earthquake. For "General", if the direction vector is predominantly horizontal then the horizontal base shear factor is used (this is the normal case), otherwise the vertical base shear factor is used.

For a detailed explanation of the dynamic response analysis results, refer to "Dynamic response analysis results".

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Dynamic response analysis results The results of a response spectrum analysis include normal deflections, forces, moments and reactions that can be displayed graphically, printed or used in a steel design in the same way that the results of a static analysis are used. In addition, spectral load cases and static load cases can be mixed together in combination load cases. The output results also include a summary of the analysis input parameters and details of the governing mode shapes, total static forces, total masses and mass participation factors. Details are given for the three global axis directions and for the direction vector. The key output results are explained in more detail as follows: Total static force The earthquake force calculated by an equivalent static method for each global axis direction. Total mass The total mass (including self mass) applied to the model for each global axis direction. Note that any mass applied to restrained degrees of freedom is ignored. Mass participation factor The results are highly sensitive to the number of mode shapes included in the analysis. An insufficient number of modes will result in an inaccurate solution. The mass participation factor (MPF) represents the contribution of a particular mode shape to the overall dynamic response of the structure. Each mode has its own MPF. The total MPF for each direction is a reliable indicator of the number of modes required. If all modes are considered then the sum of the MPF’s (the total MPF) will be 100%. In reality, we only consider a finite number of modes and the total MPF should be at least 90% for a good result. If the total MPF is less than 90% then more modes should be included in the analysis. Usually, an earthquake is applied along one of the two horizontal axes, as defined by the direction vector. For example, an earthquake acting in the X direction would have a direction vector of Dx = 1.0, Dy = 0.0 and Dz = 0.0. In this case, the total MPF in the X direction should be greater than 90%. The values of the total MPFs in the other two directions are not important.

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Analysis

A MPF that exceeds 100% indicates that the mode shapes from the dynamic frequency analysis are not accurate enough. If this happens, you should repeat the dynamic frequency analysis using a smaller tolerance. Base shear The horizontal reaction in each global axis direction shown as a percentage of the total mass. This should match the reactions shown graphically. The table in the output report showing the mass participation factors for each mode shape individually gives a good indication of the contribution of each mode shape in the overall dynamic response of the structure. From it you can quickly see which mode is dominant. DYNAMIC RESPONSE SPECTRUM (kN,T,Sec,Hz) ------------------------Spectral case 5: Sample AS1170.4 Case Mass load case: 3 Direction vector: Dx = 1.000, Dy = 1.000, Dz = 1.000 Auto scaling of base shear: AS1170.4 Vertical direction: Y-Axis Base shear: Not less than 80% of total static force Results scaled by factor: 2.825 Site factor: 0.670 Sign of the results: Mode shape 1 (Calculated) Acceleration coefficient: 0.080 Importance factor: 1.000 Structural response factor: 4.500 Spectral curve multiplier: 0.017778 Mode combination method: SRSS (Square Root of the Sum of Squares) Total MPF for Total Dominant Static Total Dominant Mass Part Base Direction Mode Force Mass Mode Factor Shear X-Axis 1 0.5371 2.1209 99.999% 100.000% 1.056% Y-Axis 3 0.2686 1.1209 29.745% 29.745% 0.023% Z-Axis 0 0.0000 0.0000 0.000% 0.000% 0.000% Mode Damping Natural Natural Mass Part Direction Shape Spectral Curve Factor Period Frequency Factor Vector 1 NEWCASTLE 2% 2.0% 0.4378 2.284 65.419% Vector 3 NEWCASTLE 0% 0.1% 0.0133 75.470 10.365% Total 75.783%

Spectral case 6: Sample General Case Mass load case: 2 Direction vector: Dx = 1.000, Dy = 1.000, Dz = 0.000 Auto scaling of base shear: AS1170.4 Vertical direction: Y-Axis

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SPACE GASS 12 User Manual Base shear: Not less than 80% of total static force Results scaled by factor: 1.532 Site factor: 0.670 Sign of the results: Mode shape 1 (Calculated) Acceleration coefficient: 0.080 Importance factor: 1.000 Structural response factor: 4.500 Spectral curve multiplier: 0.017778 Mode combination method: SRSS (Square Root of the Sum of Squares) Total MPF for Total Dominant Static Total Dominant Mass Part Base Direction Mode Force Mass Mode Factor Shear X-Axis 1 0.8363 4.1209 99.999% 100.000% 2.244% Y-Axis 3 0.4182 4.1209 50.829% 91.077% 0.239% Z-Axis 0 0.0000 0.0000 0.000% 0.000% 0.000% Mode Damping Natural Natural Mass Part Direction Shape Spectral Curve Factor Period Frequency Factor Vector 1 AS1170.4 Vector 2 AS1170.4 Vector 3 AS1170.4 Vector 4 AS1170.4 Total 95.514%

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S=.67 S=.67 S=.67 S=.67

5.0% 5.0% 5.0% 5.0%

0.6102 0.0253 0.0206 0.0153

1.639 50.096% 39.566 2.584% 48.544 25.278% 65.291 17.556%

Analysis

Buckling analysis The SPACE GASS buckling analysis module performs a rational elastic buckling analysis of a frame to determine its buckling load factors, buckling mode shapes and member effective lengths. The buckling load factor is the factor by which the loads need to be increased to reach the buckling load. A load factor less than 1.0 means that the working loads exceed the structure’s buckling capacity. For information about displaying buckling mode shapes and finding out where buckling is occurring, refer to "Buckling analysis results". The buckling modes considered in the buckling analysis involve flexural instability due to axial compression in the members (also known Euler buckling) and should not be confused with flexural-torsional buckling (torsional instability due to bending moments) or axial-torsional buckling (torsional instability due to axial loads). An accurate buckling analysis such as the one available in SPACE GASS looks at the interaction of every member in the structure and detects buckling modes that involve one member, groups of members, or the structure as a whole. A buckling analysis is an essential component of every structural design because it: 1.

Determines if the loads exceed the structure's buckling capacity and by how much.

2.

Calculates the member effective lengths for use in the member design.

3.

Determines if the static analysis results are useable or not.

Points 1 and 3 above highlight the fact that a buckling analysis must always be performed unless you are certain that the structure's buckling capacity exceeds the applied loads by a suitable factor of safety. It is very important to note that the results of a static analysis will be incorrect if the structure's buckling capacity has been exceeded (see point 3 above), and hence one of the key roles of a buckling analysis is to ratify the static analysis results.

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If you get buckling load factors that are below the minimum allowable value (eg. shown as "<0.001" when the minimum allowable value is 0.001), this could indicate an instability problem rather than a buckling problem. It is even more likely to be an instability problem if the low buckling load factors occur in every load case. If the model contains instabilities, the buckling analysis may, in some cases, give invalid results. In the absence of instability or buckling messages from the static analysis, you should always check the deflections to see if they are excessive or not. Excessive deflections are sometimes the only indicator of instabilities. Once the buckling load factors have been determined, a simple formula is used to calculate the member effective lengths as described in the next section. The effective lengths can then be automatically transferred into the steel member design modules. The method that SPACE GASS uses to calculate the buckling factors (eigenvalues) and corresponding mode shapes (eigenvectors) is based on the theory developed by Wittrick and Williams (12). Note that the magnitudes of the effective lengths or the effective length factors (k factors) from a buckling analysis cannot be used to determine if buckling is a problem or not. This can only be determined by looking at the buckling load factor.

Because plates are linear elements, they will not buckle regardless of the load applied. Refer to "Static analysis buckling" for details of some simple buckling checks that are included in non-linear static analyses. Refer to "Special buckling considerations" for details of items to be aware of when preparing your model for a buckling analysis. Refer to "Buckling analysis results" for details and interpretation of the results of a buckling analysis.

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Analysis

Buckling effective lengths The effective length of a compression member is the length of an equivalent pinended strut that has an Euler buckling capacity equal to the axial force Pcr in the member at the point of frame buckling. It can be determined from:

It is evident from the formula that because the member actual length is not involved in the calculation, subdividing the member into smaller segments does not change its effective length. Thus, the effective length of a strut is the same as the effective length of one of its segments if it has been subdivided. Effective lengths calculated by the buckling analysis can be automatically transferred into the steel member design modules. This has the obvious advantage that effective lengths don't have to be transferred manually, but it also offers design efficiencies in that the effective lengths will be calculated specifically for each design load case rather than having to use one set of effective lengths for all load cases. If you are manually specifying the compression effective lengths in the steel member design data rather than having them transferred automatically from the buckling analysis, for design groups that consist of a number of analysis members connected end-to-end, you should use the MAXIMUM (not the sum!) of its individual analysis member effective lengths. Overestimation of effective lengths Effective lengths from a buckling analysis are sometimes overestimated because the portion of the frame that buckles first determines the buckling load factor (BLF) and, consequently, controls the effective lengths of all the members in the frame. The buckled portion of the frame may just involve one or two members and may be remote from many of the members that are having their effective lengths controlled by it. For example, the buckling collapse of the left-hand column of a portal frame due to a heavy load applied to it can control the effective length of the right-hand column which has no such load applied. Consequently, each column would have a different effective length.

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SPACE GASS 12 User Manual It would be ideal if the buckling analysis could increase the BLF beyond the first buckling mode so that the effective length for each member could be based on a buckling mode that involved that member. Unfortunately, this is not often possible because once the frame has reached its first buckling mode, it has generally collapsed and cannot resist any increase in load. However, if the first buckling mode involves only minor members such as bracing or similar, rather than a collapse of the frame, it may be possible to continue the buckling analysis to a higher order buckling mode in order to get more realistic effective lengths. You can see from the above discussion that members which are lightly loaded at the point of frame buckling will get a long effective length because of their small Pcr (see the equation above). In some cases, this may result in conservative designs, however there are a few factors that can help as follows: 1.

Members that have long effective lengths are generally lightly loaded axially, and these two effects tend to cancel each other out during the design phase.

2.

For codes such as AS4100 that don't require it, turn off the slenderness ratio check at the start of the design phase. This is often very effective because, in the slenderness ratio check, a long effective length does not benefit from being cancelled out by a small axial force.

3.

For sway members, you can limit the effective lengths to a multiple of the actual member length by entering a factor into the "compression effective length ratio limit" field at the start of the design phase. In fact, effective lengths charts in most design codes limit the effective lengths for sway members to not more than 5.0 times the actual member length.

4.

For braced members, you can simply specify them as "braced" in the steel member design data for the direction(s) in which they are braced. This will limit the effective lengths from the buckling analysis to the actual member length.

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Special buckling considerations Although a buckling analysis requires no more input data than a standard static analysis, there are a number of items to be aware of when preparing a model for a buckling analysis. Restraining the structure for buckling It is important that you restrain the appropriate degrees of freedom to prevent buckling modes that can’t occur in the real structure. For example, if a plane frame is braced in the out-of-plane direction, you must ensure that the braced nodes are restrained in that direction, otherwise the buckling load factor may apply to an unexpected out-of-plane buckling mode. A general restraint is usually the most convenient way to achieve this. For example, applying a general restraint of RRFRRR to a plane frame in the XY plane will prevent all out-of-plane translations. Conversely, it is also important that you don’t prevent node movements that can occur in the real structure. For example, consider a plane frame rafter that is restrained in the out-of-plane direction at the two ends via an RRFRRR general restraint, but which is able to buckle in the out-of-plane direction between the ends. If you subsequently add some intermediate nodes to the rafter, they will also get the general restraint and this will prevent them from translating out-of-plane, changing the out-of-plane buckling characteristics of the rafter. To avoid this, you could apply restraints of RRRRRR to the intermediate nodes so that they don’t get the general restraint. Note that a static analysis of a plane frame is not as sensitive to out-of-plane restraints as a buckling analysis because static analysis out-of-plane displacements generally only occur if out-of-plane loads are applied. This is not true of a buckling analysis which can cause buckling in any direction, even if there are no loads in that direction. Buckling analysis with secondary members Structures are often modelled with the secondary members such as ties or bracing removed. If these members are required to prevent buckling of the major members in the real structure then they should be included in the buckling analysis model, otherwise the buckling capacity of the structure will be underestimated by the analysis. This is particularly true of tower structures that contain large numbers of slender members that prevent buckling of the major support members.

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SPACE GASS 12 User Manual Buckling analysis with tension-only or compression-only members Extra care must be taken with buckling analysis of structures that contain tensiononly or compression-only members. For example, consider a portal frame building modelled in 3D with tension-only wall bracing members that prevent the building from swaying longitudinally. Special treatment is required for the load cases that contain predominantly gravity loads which would cause all the wall braces to go into compression and therefore become disabled. In such load cases, the buckling analysis would yield very low buckling load factors because the wall bracing members would have been disabled and a longitudinal sway buckling mode at very low load would result. Of course, in the real structure this could not happen because the wall brace members would prevent it as soon as the sway mode was initiated. One solution is to introduce a very small horizontal load into these load cases which is small enough to have a negligible effect on the static analysis results but large enough to cause the wall brace members to go into tension. The result is that they are not removed from the buckling analysis model and are therefore able to prevent the unrealistic longitudinal sway buckling mode. Similar situations can occur in any structures that contain tension-only or compression-only members. Buckling analysis with cable members Extra care is needed for structures containing cable members because of their highly non-linear nature. Because the axial force distribution in cable structures can change dramatically as the load factor is increased beyond the working load, it is recommended that the buckling analysis be performed on combination load cases that factor the working loads up close to the buckling load and result in buckling load factors that are close to 1.0. For example, if a buckling analysis of a working load case for a cable structure yields a primary buckling load factor of 5.2, you could create a combination load case which factors up the working loads for the particular load case by 5.0 say, and then re-do the buckling analysis for the combination load case instead. If the subsequent buckling load factor is 0.90 say, then the final load factor (for the working load case) is 5.0 x 0.90 = 4.50. Buckling analysis with plate elements Because the plates in SPACE GASS are linear elements with no adjustment of stiffness due to P-delta effects, they will not buckle regardless of the load applied.

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Analysis Buckling instabilities Occasionally, you may find that a requested buckling mode can't be calculated and "Unstable" appears in the buckling output report. This occurs when a node floats free due to local buckling of all of the members to which the node is connected. Sometimes it is possible to avoid this problem and calculate higher order buckling modes by adding intermediate nodes to the members which have buckled. Modelling multiple structures in one job It is sometimes useful to model more than one structure in a single job, however this is not recommended if you are performing a buckling analysis to obtain compression effective lengths. The buckling analysis finds the lowest buckling load factor for the entire model and then calculates the effective lengths for all the members in the model based on that buckling load factor. For example, if you have modelled structure A and structure B in one job, and structure A has the lowest buckling load factor, the effective lengths for structure B will be incorrectly based on the buckling load factor from structure A. SPACE GASS can't detect if there are multiple structures in a single model and therefore you need to put them into separate jobs if you want to use effective lengths from a buckling analysis.

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Running a buckling analysis You can run a buckling analysis by selecting "Buckling Analysis" from the Analysis menu. The input data requirements for a buckling analysis are the same as those for a static analysis. No extra buckling data is required. You do not have to run a static analysis before a buckling analysis.

Load case list If you want to analyse all load cases then this field can be left blank, otherwise you should type in a list of load cases (separated by commas or dashes) that you want analysed. For the fastest analysis time you should generally analyse only the load cases that can occur in reality. For example, there is no point in analysing a live load case on its own because it can't occur in real life without being combined with dead load.

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Analysis This means that you should generally analyse just the combination load cases and not the primary load cases that the combinations are made from. When specifying the load case list, you can either list them directly, or you can click the button to display and select from a list of the load cases currently in the job as shown below.

Tolerance The accuracy to which the buckling load factors will be calculated. For example, a tolerance of 0.01 means that the load factors will be within +/- 0.01 of the exact value.

Each extra decimal place in the tolerance will increase the number of iterations per mode by 3 or 4. For example, a tolerance of 0.001 will require 3 or 4 more iterations per mode than a tolerance of 0.01. Load factor upper limit The upper limit above which the buckling analysis will no longer search for buckling load factors. Once this limit is reached, the analysis will stop, even if not all requested buckling modes have been calculated.

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SPACE GASS 12 User Manual Load factor lower limit The lower limit below which the buckling analysis will not search for buckling load factors. Buckling modes The number of buckling modes that are required. Normally only the first buckling mode is of interest, because beyond that the structure has usually collapsed and further modes are of academic use only. If the first buckling mode is caused by local buckling of a slender member or group of members rather than the frame as a whole, the model should be changed so that overall frame buckling occurs instead. One way of achieving this could be to change the slender members into tension-only members so that they become disabled rather than buckle (see also Members). You should view the buckling mode shapes graphically to determine whether or not overall frame buckling has occurred. Retain results of other load cases If you have specified that not all load cases are to be analysed and, if results already exist for some of the non-specified load cases, you can choose to retain them or have them deleted. Check for non-existent load cases If you have defined combination load cases that contain other load cases which don’t yet exist, this option will detect and report them. It is optional because some users prefer to have a standard set of combination load cases that contain primary load cases which are just ignored during the analysis if they don’t exist. Stabilize unrestrained nodes Nodes that are free to rotate or translate in one or more directions without resistance from interconnecting members, restraints or constraints can be automatically restrained during the analysis so that instabilities don’t occur. For example, if a node was connected to a number of members, all of which were pin-ended, a rotational instability would normally result due to the unrestrained rotation of the node. However, the stabilize option would apply a temporary rotational restraint to the node during the analysis, preventing an instability. Although this solves many instabilities, it doesn’t fix them all, and the prevention of non-trivial instabilities is still dependent on good modelling practice.

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Analysis Extra iterations for mode shape accuracy The buckling analysis is complete when the buckling load factor has reached the desired accuracy (as specified by the tolerance), however it is possible that at this point the buckling mode shapes are not totally accurate. Mode shape accuracy can be achieved by turning on the "Extra iterations for mode shape accuracy" option, however because buckling mode shapes are only used as a visual aid to assess the buckling location and its shape then the extra iterations and analysis time involved is not usually warranted. Solver The "Paradise" solver is a new parallel multi-core sparse solver that fully utilizes the multiple cores in a modern computer's CPU. All of the available cores are run in parallel to get the maximum possible analysis speed. It also takes full advantage of the sparseness of the structural matrix during the solution to minimize memory requirements and further increase the speed. The Paradise solver is the recommended setting for all static analyses. One current restriction of the Paradise solver is that it doesn't generate buckling mode shapes and so if mode shapes are essential then you should use the Wavefront solver instead. This restriction is likely to be removed in a future version. Note that buckling mode shapes are for visual purposes only and do not affect the calculation of the buckling load factor, the member effective lengths or any of the other modules that use the buckling analysis results. The "Wavefront" solver also takes into account the sparseness of the matrix but doesn't run in multi-core mode. It is generally slower than the Paradise solver and can be used if the Paradise solver is unable to obtain a solution or if you require buckling mode shapes. The "Watcom" solver is the one used in pre-SPACE GASS 12 versions. It is considerably slower than the Paradise and Wavefront solvers and is therefore of limited use. All three solvers should yield virtually identical results. Optimization method The wavefront optimizer can be de-activated or it can be operated in one of four modes as follows. 1. No optimization

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SPACE GASS 12 User Manual 2. Auto mode - SPACE GASS trials the "General" and various "Linear" modes and then uses the one that gives the smallest frontwidth. It doesn't add significant time to the analysis and is the recommended setting.



5. Circular mode - You select either of the X, Y or Z axes about which optimization proceeds around an arc through the structure. See also The wavefront optimizer. Optimization axis If you have selected "Linear" or "Circular" for the wavefront optimization mode then you must select the axis or vector along or about which optimization will proceed. See also The wavefront optimizer. Coordinates of optimization centre If you have selected "Circular" for the wavefront optimization mode then you must select the centre of rotation about which optimization will proceed. See also The wavefront optimizer. Axial force distribution The buckling properties of a structure are largely dependent on the axial force in the members. The buckling analysis module performs its own static analysis first to determine the axial force distribution and you can nominate either linear or nonlinear for this initial static analysis phase. Generally, the choice between linear or non-linear doesn't significantly affect the buckling load factor and, because linear is faster, it is recommended for most frames. Naturally, some structures, such as those containing cable members, which cannot be analysed linearly, require you to select non-linear.

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Analysis When all of the information has been entered, the buckling analysis module calculates the buckling load factor and mode shapes for each load case and then saves them ready for graphical or text report output. If you want to terminate the analysis before it is finished, just press ESC or the right mouse button.

Because plates are linear elements, they will not buckle regardless of the load applied.

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Buckling analysis results At the end of the buckling analysis, a message showing the lowest buckling load factor is displayed as follows.

This gives an instant indication of whether the buckling capacity of the frame has been exceeded or not. A buckling load factor of less than SF x 1.0, where SF is a suitable safety factor would be unsatisfactory. Based on the buckling load factor for each load case, a simple formula is then used to calculate the member effective lengths as described in "Buckling effective lengths". The effective lengths can then be automatically transferred into the steel member design modules. For a more detailed list of the buckling load factors and member effective lengths for each load case, you should view or print a report that includes the buckling load factors and/or buckling effective lengths. If you get buckling load factors that are below the minimum allowable value (eg. shown as "<0.001" when the minimum allowable value is 0.001), this could indicate an instability problem rather than a buckling problem. It is even more likely to be an instability problem if the low buckling load factors occur in every load case. By displaying the buckling mode shapes, you can generally see where the buckling would occur, however some models show no movement at all. In these cases, the buckling generally involves node rotations without any translations, making it difficult to see the source of the buckling. The buckling load factor report, however, gives the locations of the maximum node translations and rotations which can help to identify where the buckling is happening. Load Load Node at Node at

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Analysis Case Mode Factor Tolerance Iterations Max Trans Max Rotn 1 1 3.207 0.008 11 4 (X) 3 (Z) 2 1 0.801 0.008 8 4 (X) 3 (Z)

In the above example, the buckling mode involves translations in the X-axis direction and rotations about the Z-axis. If you want to display any higher order mode shapes, just press the "Filters" toolbar button and then list the mode shapes required in the "Buckling modes" field.

If a frame appears to buckle in the wrong direction, it is because the buckling mode shape diagrams are only intended to show the mode of buckling and not its direction or magnitude. When displaying the buckling mode shapes graphically, SPACE GASS makes no attempt to show the member curvature between end nodes (ie. the node positions are simply joined by straight lines). You can, however improve the look of the mode shapes by adding intermediate nodes to the members.

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Analysis warnings and errors SPACE GASS performs numerous checks for illegal and inconsistent data. Many of these checks are done in the data input modules and any errors detected there must be corrected immediately. However, some errors and warnings such as instabilities and ill-conditioning cannot be detected until the analysis phase. If any errors in the data are detected, SPACE GASS lists them on the screen, aborts the analysis and then returns to the main menu, ready for correction of the offending items. Warnings are displayed at the end of the analysis and do not cause it to abort. Node # not found for member # A member is connected to a non-existent node. Direction node # not found for member # A member has referenced a non-existent direction node. Section # not found for member # A member has referenced a non-existent section property. Section # has impractically large section properties for the frame size The properties of a section are too large for the frame dimensions. This error is often due to the section properties being input in the wrong units. Material # not found for member # A member has referenced a non-existent material property. Member # has zero length A member is connected to two nodes with identical coordinates. Restraint applied to non-existent node # A restraint has been applied to a node which doesn’t exist. Slave node # not found A non-existent node has been specified as a slave node. Master node # not found for slave node # A non-existent node has been specified as a master node.

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Analysis A constraint has been applied to a restrained DOF on node # Any restrained degrees of freedom for a slave node cannot be constrained to a master node. Node # has been specified as both slave and master A master node cannot be the slave of another master node. Member # with PA<>0.0 must have identical Y and Z axis fixities at an end Because of the difficulty involved in calculating the stiffness matrix for a member with a non-zero principal angle when the member end fixities are about its nonprincipal axes, the Y and Z fixities at an end must be the same. Cable member # must not have any translational fixities released For stability, cable members must have all of their translational fixities fixed. Cable member # must not have member offsets Cable members cannot have member offsets. Cable member # must not have semi-rigid joints Cable members are always assumed to be pin-ended, and hence cannot have semirigid joints. Member # must not have shear fixity released with semi-rigid joints Members with semi-rigid joints cannot have shear fixities released. This restriction only applies when the semi-rigid joint and the shear fixity act in the same plane. Node load on non-existent or dummy node #, load case # A node load has been applied to a non-existent node. Prescribed displacement on non-existent or dummy node #, load case # A prescribed displacement has been applied to a non-existent node. Concentrated load on non-existent member #, load case # A concentrated member load has been applied to a non-existent member. Distributed force on non-existent member #, load case # A distributed member force has been applied to a non-existent member. Distributed torsion on non-existent member #, load case # A distributed member torsion has been applied to a non-existent member. Prestress load on non-existent member #, load case #

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SPACE GASS 12 User Manual A prestress load has been applied to a non-existent member. Prescribed displacement applied to end of cable member #, load case # Nodes at the ends of cable members must not have prescribed displacements applied to them. Prescribed displacement applied to released restraint on node #, load case # Prescribed displacements can only be applied to node degrees of freedom which are restrained. Prescribed displ. applied to master constraint DOF on node #, load case # Prescribed displacements must not be applied to master node degrees of freedom which are constraining a slave node. Concentrated load is off the end of member #, load case # A concentrated member load has been located beyond the ends of the member. Concentrated load applied to cable member #, load case # Concentrated member loads must not be applied to cable members. Distributed force is off the end of member #, load case # A distributed member force has been located beyond the ends of the member. UDL must act over full length of cable member #, load case # Uniformly distributed loads applied to cable members must act over the entire cable length. Trapezoidal load applied to cable member #, load case # Distributed trapezoidal loads must not be applied to cable members. Distributed torsion is off the end of member #, load case # A distributed member torsion has been located beyond the ends of the member. Distributed torsion applied to cable member #, load case # Distributed torsion loads must not be applied to cable members. Load case # has been specified as both primary and combination Load cases can be primary or combination, but not both. Combination # contains non-primary load case # Combination load cases can only be made up from primary load cases. Combination load cases cannot be further combined.

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None of the load cases selected exist There are no valid load cases in the load cases list selected for analysis. Insufficient space on drive C, # bytes extra required The analysis module has detected that there is not enough space left on the hard disk for the analysis to run to completion. Extra space equal to the number of bytes shown is required. You should terminate the analysis, remove any unwanted data files or programs and then try the analysis again. Cable member # is ill-conditioned in load case # The program was unable to accurately calculate the cable geometry and stiffness matrix. Member # has buckled in load case #, axial load = 123.23. Continue? During a non-linear analysis, the program was unable to calculate the stiffness matrix for the member because its Euler buckling load was exceeded. If you continue, the member is simply disabled for the rest of the analysis iterations. Note that this message is the result of a simple local member buckling check only. Overall frame buckling or buckling of multiple members is not considered! The local member buckling messages can be suppressed by clearing the appropriate check box at the start of the analysis. Instability found at member # in load case # An instability has been detected at a specified member. The instability could be located at either end of the member. Not all load steps were completed The load was applied in more than one step, however it was stopped before all steps were completed. Because the full load was not reached, the results cannot be used for the load cases being analysed. WARNING: Possible ill-conditioning detected, check reactions Ill-conditioning may have been detected. If the reactions equal the applied loads then no ill-conditioning has occurred. This message is only a warning which can be suppressed from the output reports if necessary. WARNING: Analysis did not reach desired convergence in all load cases The level of convergence in a non-linear analysis has not reached the required convergence accuracy for some load cases. This is not necessarily fatal if the convergence achieved is close to that requested. Note also that some of the load

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SPACE GASS 12 User Manual cases may have fully converged and this can be checked by looking at the output reports.

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Steel Member Design Steel member design Throughout this chapter it can be assumed that all information applies equally to all of the supported steel member design codes unless specifically stated otherwise. This chapter describes in detail the data required to be input before a design or check can proceed. It discusses the internal methods, philosophies and assumptions that the program uses as it designs or checks members, and it explains how to initiate the actual design or checking process once the steel member design data has been input. ! IMPORTANT NOTE ! Before you use the steel member design module, you should read all of the assumptions described later in this chapter (see also "Steel member design/check assumptions") to verify that its performance and capabilities are adequate for your situation. It is up to you to determine whether or not the steel member design module is suitable for your requirements. The steel member design module is a general purpose design and code checking program which reads the frame analysis output data, calculates the critical location and load case for each member and then selects the most suitable steel member size from a library of standard sections. Alternatively, you may specify a steel member size to be checked and the program determines whether or not the member is adequate. For a given frame, you can specify any selected number of members to be designed or checked. The design module is also capable of passing the designed steel sizes back into the frame analysis data and re-analysing the structure. This process can be iterated until the results converge. It usually only takes two or three iterations. During the design/check phase SPACE GASS automatically calculates the load factor for limit states codes or combined stress ratio for working stress codes at numerous stations along each member. It considers yielding of the cross section, lateral buckling, slenderness ratios, and all possible combinations of shear, tension, compression and bending for both in-plane and out-of-plane failure.

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The steel member design module doesn’t consider torsional effects. After all specified members have been designed or checked, a detailed report can be produced for each member showing the critical location or segment on the member, the critical load case, section properties, effective lengths, and the complete computations involved in the design. Sections of the report can be suppressed if required. A color-coded graphical representation of the design/check results can also be displayed. The SPACE GASS steel member design module can handle most types of steel members including beams, columns, ties, struts, braces, and members subjected to combinations of axial loads, shear forces and bending moments (uniaxial or biaxial). All references to BS5950 in this document apply to BS5950-1:2000. Although SPACE GASS still has a design module for BS5950:1990, it is now obsolete and is not referred to in this document. The AISC-LRFD, EUROCODE 3, AS4100, NZS3404, BS5950 and HK CP2011 modules assume that second order effects have been taken into account by a second order elastic analysis. Moment magnification is not considered. The NZS3404 module uses the "Other than capacity" design method with non-seismic ductility categories only. Refer to "Steel member input methods" for details on how to input steel member design data. Refer to "Running a steel member design" for details on how to perform a steel member design. Refer to "Steel member design results" for details and interpretation of the results of a steel member design.

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Steel Member Design

Steel member input methods Before you can perform a steel member design, you must define each of the steel members you wish to design and then input some design parameters for each of them. This can be done in three ways as follows. 1.

Auto-create steel members This option performs a quick initial input of the steel members and their design parameters for the entire model or for any part of it that you wish to select. After the quick initial input, you can refine the design parameters for each steel member by using a steel member input form or datasheet (see items 2 and 3 below). You can also skip the auto-create step completely if you prefer to input the steel design data from scratch using a steel member input form or datasheet.

2.

Steel member input form This option allows you select a steel member graphically and then define or edit its design parameters via a form. It is restricted to one steel member at a time.

3.

Steel member input datasheet This option lets you select one or more steel members graphically and then define or edit their design parameters via a datasheet. It can handle multiple steel members, however they must have been previously defined using methods 1 or 2 above. Alternatively, you can select "Steel Member Design Input-Datasheet" from the Design menu to open a datasheet and input or edit design parameters for steel members regardless if they have previously been defined or not.

The recommended procedure is to use the auto-create tool to perform a quick initial setup of the steel members and then refine them using a steel member input form or datasheet. Each of the three input methods are explained in detail in the following sections. If you want to have multiple steel members with identical design parameters, you can copy the design parameters from one steel member to many others by using the "Copy steel member properties" tool. Note, however, that you can’t copy to steel members that haven’t been defined yet.

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Auto-create steel members This tool automatically creates multiple steel design members (also known as "design groups") from a selection of analysis members. Each generated steel design member can contain multiple analysis members connected end-to-end, provided they are of the same cross section, are generally collinear and don’t extend past a major axis support. You can access the auto-create steel members tool by selecting "Steel Member Design Input-Auto create multiple steel members" from the Design menu or selecting "Auto-create multiple steel members" from the floating menu. You can select analysis members from different locations throughout the model and with different section properties, and SPACE GASS will automatically sort through them and group them appropriately into steel design members. You can even select the entire model and have all of the steel design members created automatically. However, you should check the generated members to ensure that their effective lengths, restraints and other data are correct. The numbering convention adopted by this operation is such that the number of each generated steel design member is set to match the number of the first analysis member that it contains. This makes it easy to keep track of how the steel design members relate to the analysis members. However, please be aware that any existing steel design members that don’t follow this convention will be overwritten if their numbers clash with the new steel design members being generated. Of course, any steel design members that contain the selected analysis members will also be overwritten during the generation. After you have selected the analysis members to be grouped into steel design members, click the right mouse button and select "Auto-create multiple steel members" from the floating menu (or select "Ok" if you initiated the operation from the menu). You can then specify restraint, effective length and other data for the generated steel members via the forms shown below.

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Specify Flange Restraints Manually Select this option if you want to directly specify all of the flange restraints along the generated steel members in the next form. Otherwise, the flange restraints will be placed in accordance with the data you specify in this form. End Flange Restraints These are the flange restraints that will be placed at the ends of the generated steel members.

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Intermediate Flange Restraints Flange restraints will be placed at the intermediate nodes along the generated steel members depending on which options you select in this area of the form. Your choices are any or all of the following: 1.

Apply flange restraints to all intermediate nodes If selected, intermediate flange restraints of the type you specify will be placed on both flanges at every intermediate node.

2.

Apply flange restraints to nodes connected to other members If selected, intermediate flange restraints of the type you specify will be placed at the intermediate nodes that are connected to other members. You have the option of ignoring interconnecting members that lie in the plane of the steel member (ie. in the plane of the steel member’s web). You can also control which flanges to which the restraints are applied.

3.

Apply flange restraints to restrained intermediate nodes If selected, intermediate flange restraints of the type you specify will be placed at the intermediate nodes that have analysis restraints applied to them. Analysis restraints that only apply in the direction of the plane of the steel member’s web are ignored. Note that this only applies to normal analysis restraints and not the general restraint.

Tolerances The tolerances affect whether or not a selection of analysis members are suitable for grouping into a steel design member. A selection of analysis members of the same cross section connected end-to-end will be able to be grouped into a steel design member provided the bend angle, twist angle or step distance between adjacent analysis members do not exceed the tolerances you specify. Delete all Existing Design Groups First If you select this option, all steel design members will be deleted before the new steel members are generated. Otherwise, only those steel design members that contain the selected analysis members will be deleted before the generation.

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Steel Member Design After clicking the "Next" button, the following form appears. For detailed information about the data in the form, refer to "Steel member design data".

All steel design members generated will be created with the data that you specify in this form. After the steel design members have been created, you should check each one, paying particular attention to the following: 1.

You should split any steel design member that extends past an interconnecting member that effectively acts as a major axis support point for the design member.

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SPACE GASS 12 User Manual 2.

If you have specified that bending effective lengths are to be calculated automatically based on the flange restraints, they will be calculated such that they never substantially exceed the actual length of the steel design member. If the unrestrained flange length is longer than this (ie. the bending effective length is longer than the steel design member length) then you should specify them manually rather than having them calculated automatically.

You can show the steel design members graphically by clicking the button near the bottom of the side toolbar. They show up as thickened lines that are drawn slightly shorter than their actual length so that you can easily see where they start and finish. Steel design members can be viewed or edited graphically on an individual basis as described in "Steel member input form", "Steel member input datasheet" or via the steel member design datasheet. For an overview of the various methods available for inputting steel member design data, refer to "Steel member input methods".

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Steel Member Design

Steel member input form This tool allows you to graphically define and edit steel design members (also known as "design groups"). Note that multiple steel design members can be defined in a single operation using the "Auto-create steel members" tool. You can access the steel member input form by selecting "Steel Member Design Input-Graphical" from the Design menu or selecting some members and then "Steel Member Design Input (Form)" from the floating menu. It is recommended that you initially generate all the steel design members using the "Auto-create steel members" tool and then check and edit them on an individual basis using the procedure described here. Each steel design member contains one or more analysis members connected endto-end. After you have selected the analysis members that you wish to include in a steel design member, click the right mouse button and select "Steel Member Design Input (Form)" from the floating menu (or select "Ok" if you initiated the operation from the menu). Because the top flange for a steel design group is taken to be the same as the top flange for the first member in the design group, it is important to be able to control which member comes first in the design group. Flange restraint positions are also referenced from the end of the first member in the design group. If you are inputting a new design group, the member that you select first will be placed first in the design group (assuming that it is at either end of the group). If you want to select a "first" member, you should pick it directly or ensure that it is the only member selected if you use a window. If you use a window and select a group of members initially, then the end one with the lowest member number will be placed first in the design group. In the steel member form that appears, type in the data for the selected design group, and then click the form Ok button. For detailed information about the data in the form, refer to "Steel member design data".

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"Use Previous" button Click the "Use Previous" button to set all the data in the form to the same as when the form was previously used. You can show the steel design members graphically by clicking the button near the bottom of the side toolbar. They show up as thickened lines that are drawn slightly shorter than their actual length so that you can easily see where they start and finish.

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Steel Member Design

You can also show the flange restraints graphically by clicking the button near the bottom of the side toolbar. It enables you to see exactly where the flange restraints are and whether they are on the correct flange or not. For an overview of the various methods available for inputting steel member design data, refer to "Steel member input methods".

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Steel member input datasheet This tool allows you to graphically edit steel design members (also known as "design groups") that were previously defined using the "Auto-create steel members" and/or "Steel member input form" tools. You can access the steel member input datasheet by selecting "Steel Member Design Input-Datasheet" from the Design menu or selecting some members and then "Steel Member Design Input (Datasheet)" from the floating menu. After you have selected one or more steel design members, click the right mouse button and select "Steel Member Design Input (Datasheet)" from the floating menu (or select "Ok" if you initiated the operation from the menu). For detailed information about the data in the datasheet, refer to "Steel member design data".

Refer to "Using datasheets" for information on how to operate the above datasheet. For an overview of the various methods available for inputting steel member design data, refer to "Steel member input methods".

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Steel Member Design

Copy steel member properties This tool lets you copy the design properties of a steel design member (also known as a "design group") to a selection of destination steel design members. Note that the properties can only be copied to members that have already been set up as steel design members. The procedure is as follows. 1.

Select the source member that you wish to copy the properties of, click the right mouse button and then select "Copy Steel Member Properties" from the floating menu that appears. OR Select "Copy Steel Member Properties" from the Design menu and then select the source member that you wish to copy the properties of.

2.

Select one or more destination members by picking them individually or by putting a selection window around them and then click the right mouse button and click "Ok".

3.

The steel design properties of the source member will then be copied to the selected destination members.

4.

Select another source member, or press ESC or the right mouse button to exit from the tool.

After the copy, you should check the destination members to ensure that the effective lengths, flange restraints and other data are appropriate. In particular, check that the effective lengths are correct and that the flange restraints are not located off the ends of the steel design member. For an overview of the various methods available for inputting steel member design data, refer to "Steel member input methods".

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Steel member design data This section describes the steel member design data that is required to be input before you can design and/or check steel members that are part of a frame analysis model. For an overview of the various methods available for inputting steel member design data, refer to "Steel member input methods".

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Steel Member Design The form that appears when you input steel member design data graphically is shown above. The steel member datasheet contains the same information in a different format. Group Each steel design member is made up of one or more analysis members. Hence, the concept of steel design groups is introduced. A steel design group usually represents a single piece of steel in the real structure. It could be modelled as a single member or a number of members in the analysis model. In order to make it easier to relate member numbers to group numbers, it is often a good idea to give the design group the same number as the first member in the group. Otherwise, there is sometimes a tendency to confuse member numbers and group numbers when scanning the design output data. By default, SPACE GASS will give a design group a number corresponding to the first of the members selected (when performing a graphical steel frame data input). You can, of course, change this if you wish. Description An optional brief description of the steel design group. Member list A list of analysis members to be combined into the steel design group. This is often only one member in each group. Because the top flange for a steel design group is taken to be the same as the top flange for the first member in the design group, it is important to control which member comes first in the design group. Flange restraint positions are also referenced from the end of the first member in the design group. See also Member groups. Strength grade The strength grade for members can be set to normal or high. The actual yield strengths are taken from the standard section libraries supplied with SPACE GASS. All of these libraries can be viewed or edited (see also Section libraries). Choices are:

Normal, High.

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Units The compression effective lengths and flange restraint positions can be specified as actual distances or as ratios of the design group length. Choices are:

Actual, Ratio.

Load height position The load height position is used to allow for the case when a member is subjected to a downwards load acting above its shear centre causing an increased tendency for the flange to buckle laterally (out-of-plane). The load height position can be set to "Top flange" if this occurs, or "Shear centre" if the predominant load is positioned at the shear centre or below such that it resists lateral buckling of the flange. Choices are:

Shear centre, Top flange.

The load height position affects the value of the load height factor kl which is used to calculate the bending effective length of the member.

Destabilizing and stabilizing loads

See also Load height factor.

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Steel Member Design

Scan code In order to control the types of steel sections that the program selects during the course of a design, a library scan code is required. This allows you to select the types of sections that should only be considered for each member. For example, you could use it to tell the program that only I-sections were to be considered for the design of a portal frame column. Without the library scan code the program would simply choose the lightest adequate steel section from the library, regardless of its type or shape. The library scan code is simply a list of up to four characters that contains the group codes of sections that are to be considered during the design of a member. You can input the scan code directly or click the "Select" button and then choose the section types you require and the scan code will be created for you. Compression effective lengths (Lc major and minor) These are the effective lengths for overall buckling about the major and minor axes due to axial compression. Depending on the "Units" selected, the Lc values may be expressed as an absolute length or as a ratio of the total group length. Compression effective lengths can be calculated from a buckling analysis, however you can elect to input them directly if you prefer. To have them calculated, select the "Calculate from Buckling Analysis" check box. Of course to have Lc calculated, you must have the buckling analysis module (it is not a standard program feature) and you must run a buckling analysis before you can run the steel member design. Having the Lc values calculated automatically is more efficient than specifying them directly because case specific Lc values can be calculated for each design load case. If you specify Lc values directly then they are used for every load case. If the Lc values are not being transferred automatically from a buckling analysis, for design groups that consist of a number of analysis members connected end-toend, you should use the MAXIMUM (not the sum!) of its individual analysis member effective lengths. The "Braced in Position at Both Ends of Group" check boxes indicate whether or not the group is braced for each of the major and minor axis directions. If you specify that the group is braced then its compression effective length in the direction you specify will not be allowed to exceed the overall group length, regardless of whether it was calculated from a buckling analysis or specified

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SPACE GASS 12 User Manual directly by you. Because this can substantially reduce the effective lengths used in the design, please use this option with care!

It is sometimes useful to model more than one structure in a single job, however this is not recommended if you are performing a buckling analysis to obtain compression effective lengths. The buckling analysis finds the lowest buckling load factor for the entire model and then calculates the effective lengths for all the members in the model based on that buckling load factor. For example, if you have modelled structure A and structure B in one job, and structure A has the lowest buckling load factor, the effective lengths for structure B will be incorrectly based on the buckling load factor from structure A. SPACE GASS can't detect if there are multiple structures in a single model and therefore you need to put them into separate jobs if you want to use effective lengths from a buckling analysis.

During the design phase, the compression effective lengths as calculated or defined by you may be adjusted depending on parameters you specify at the start of the design phase. For more information about this, refer to Running a steel member design.

For single angle sections, the compression effective lengths must be input relative to the non-principal axes. For AS4100, BS5950, NZS3404, AS4600, AISCLRFD, AISC-ASD, HK CP2011 and EUROCODE 3, they are optionally converted to the principal axes during the design/check phase. To prevent this conversion, refer to Running a steel member design.

In order to cater for all design code naming conventions, the compression effective lengths are referred to as "Lc major" and "Lc minor" in this document and in the data entry parts of the program. However, in the design output reports, they are changed to match the notation of the design code that was used. See also Buckling effective lengths. Bending effective lengths (Lb +ve and –ve) Bending effective lengths for positive moments (Lb +ve) and for negative moments (Lb –ve) are normally calculated based on the flange restraints that you specify,

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Steel Member Design however you can elect to input them directly if you prefer. To have them calculated, select the "Calculate from Flange Restraints" check box. During the design, if you have elected to have the bending effective length calculated, it is taken as the length of the segment under consideration multiplied by three additional factors kt twist factor), kl (load height factor) and kr (lateral rotation factor) such that Lb = Lseg x kt x kl x kr. Alternatively, if you have specified the bending effective length directly then the specified value is used without modification. kt, kl and kr are fully explained in AS4100/NZS3404 clause 5.6.3. In AS1250, SABS0162, BS5950, AS3990, HK CP2011 and EUROCODE 3 there are no kt kl and kr factors and so SPACE GASS uses the rules of AS1250 clause 5.9, SABS0162 clause 7.2.3, BS5950 clause 4.3.5, AS3990 clause 5.9, HK CP2011 clause 8.3.4 or EUROCODE 3 clause F.1.2 to calculate equivalent kt, kl and kr factors which, when multiplied together, produce an overall effective length factor kb.

In order to cater for all design code naming conventions, the bending effective length is referred to as "Lb" in this document and in the data entry parts of the program. However, in the design output reports, it is changed to match the notation of the design code that was used. See also Twist factor. See also Load height factor. See also Lateral rotation factor. Flange restraints Flange restraint positions are referenced from the end of the first member in a design group. SPACE GASS assumes that there is a restraint at each end of a group and you should therefore specify the intermediate restraint positions only. Restraint positions should be specified independently for the top and bottom flanges. Up to 100 intermediate positions can be specified for each flange. If there are no intermediate restraints for a particular flange then the restraint positions field should be left blank. When specifying restraint positions, you can use @’s to specify relative positions or groups of equally spaced positions. For example, restraint positions of

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SPACE GASS 12 User Manual 1.2,2.4,3.6,4.8,6.0,6.6,7.2,7.8,8.4 could be specified as [email protected],[email protected], or positions of 1.2,1.8,2.7,3.3 could be specified as 1.2,[email protected],2.7,[email protected]. Depending on the "Units" selected, the restraint positions may be expressed as an absolute distance or as a ratio of the total group length. Flange restraint types must be specified for each intermediate restraint position and for the two ends of the design group. Refer to "Flange restraints" for restraint definitions. Choices are:

Full (F) Partial (P) Lateral (L) Full and rotational (R) Partial and rotational (S) Unrestrained at end (U) Continuous lateral restraint (C) Ignore segment (I)

The top flange of a member is the flange on the positive local y-axis (or zaxis if the section has been flipped) side of the member. The top flange of a group as a whole is defined such that it is the same as the top flange of the first member in the group. You can verify graphically which is the top flange by clicking the button near the bottom of the side toolbar. It displays a small triangle that points to the top flange of each member.

For single angle sections, flange restraints must be input relative to the nonprincipal axes. For AS4100, BS5950, NZS3404, AS4600, AISC-LRFD and AISCASD, they are converted to the principal axes during the design/check phase. See also Flange restraints. See also Effective flange restraints.

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Steel Member Design Consider eccentric effects For members that have eccentric end connections, you can elect to consider or ignore the resulting eccentric moments. Eccentric moments are only added if they increase the normal design moments. Note that even if you select this check box, you can disable eccentric effects globally by deselecting the eccentric effects check box in the steel member design/check form. Maximum bolts in cross section In order to calculate the effective web and flange areas, and subsequent member capacities, the presence of bolt holes at the member ends must be taken into account. SPACE GASS requires you to estimate the number and diameter of bolts per cross section at the ends of each member to be designed or checked. A bolt count of zero indicates that the member end is welded. During the design, SPACE GASS checks to see that the bolts per cross section specified can be fitted into the cross section. If not, the number is reduced to the maximum that can be accommodated. If the member is too small to take even a single bolt then the connection is assumed to be welded. Bolt diameter End connection bolt diameter. Angle type In order to define the geometry of single or double angle sections, SPACE GASS requires the angle section type to be input. Choices are:

Single angle, Double angle with short legs connected, Double angle with long legs connected, Double angle starred (equal angles only).

Double angle sections are assumed to have no space between the individual angle sections. ! IMPORTANT NOTE ! The AS1250, SABS0162 and AS3990 modules assume that double angles are connected together at intermediate points sufficient to ensure that half of the design axial compressive force for the combined section does not exceed the

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SPACE GASS 12 User Manual compressive capacity of each angle section considered individually using an effective length (for buckling of the sections away from each other) equal to the distance between connection points. The AISC-LRFD, EUROCODE 3, AS4100, NZS3404, BS5950 and HK CP2011 modules convert double angle sections into the equivalent Tee section and then treat them as a solid Tee shape. They do not support double starred angles.

Angle section orientation

All of the possible arrangements involving single and double angles are shown in the diagrams above. It is important to note that the major axis of a single or double angle section is assumed to be parallel to the short leg(s) of the section as shown in the diagrams.

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Steel Member Design

For double equal angles, the long leg is assumed to be the vertical leg in the diagrams above. Note that in SPACE GASS 10 and earlier, double equal angle sections with long legs connected were adjusted internally and treated as though their short legs were connected. This adjustment was removed in SPACE GASS 11 and later versions. The design procedure for angle sections is considerably more complicated than for most other sections. This is due to the significant moments generated by eccentric end connections which cannot usually be avoided when working with angles. SPACE GASS is capable of taking these effects into account for both single and double angle sections.

When designing/checking single or double angle sections for AS1250, SABS0162 or AS3990, SPACE GASS considers only axial forces and shears. Normal bending moments are not considered. The only moments considered are those due to the eccentric end connections. This is not the case with the other design modules. They consider all axial forces, shears and moments together with any extra eccentric moments (if appropriate). Furthermore, for single angle sections, the effective lengths and flange restraints must be input relative to the non-principal axes. For AS4100, BS5950, NZS3404, AS4600, AISC-LRFD and AISC-ASD, they are converted to the principal axes during the design/check phase. End connection For non-symmetric members subjected to axial loads, such as angle sections, channels and Tees, the program needs to know which leg, flange or web is connected so that the extra moments due to possible eccentric end connections can be calculated (if appropriate). Choices are:

Concentric, Flange(s) (for I, H, T or channel sections), Web (for channel or T sections), Angle short leg, Angle long leg (vertical leg for equal angles before being flipped or a direction angle, direction node or direction axis applied).

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SPACE GASS 12 User Manual Design criteria Most designs aim to minimize the structure weight, however if you are constrained to a certain member depth then you can elect to minimize the member depth instead. Choices are:

Weight, Depth.

Use Previous button Click the "Use Previous" button to set all the data in the form to the same as when the form was previously used. See also Steel member input methods. See also Steel member design text. See also Running a steel member design.

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Steel Member Design

Steel member design sign conventions The steel member design module deals only with the member cross section axes. The longitudinal axis of the member is of no relevance. For most section types, steel member design input and output data always relates to the major and minor principal cross section axes. The only exception is for single angle sections where the effective lengths and flange restraints must be input relative to the non-principal axes (the axes parallel to the angle legs) for all design codes. During the design phase, the data for single angle sections is converted to the principal axes for AS4100, BS5950, NZS3404, AS4600, AISC-LRFD and AISCASD. Output reports for those codes also show the data in principal axes for single angle sections. See also Column and beam Tees.

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Member groups In a typical structure, the actual beams, columns, struts, ties, etc. are modelled in SPACE GASS as members connected together at nodes. Sometimes, however it is convenient and often necessary for members to have nodes placed at intermediate positions along them so that they are subdivided into smaller members. This can occur when another member intersects a member at an intermediate point or when a node is simply placed at an intermediate point so that deflections, forces and moments are calculated at that point during the analysis. Quite often the placement of intermediate nodes along a member is done purely for frame analysis modelling purposes rather than due to an actual discontinuity or connection in the real structure. For this reason, SPACE GASS allows you to group frame analysis members together and design them as though they are a single entity (as they are in the real structure). In the remainder of this manual a "design group" represents an actual member in the real structure which consists of one or more frame analysis members grouped together end-to-end.

Note that in the following discussion, members in a group can be listed in either direction. For example, "1,3,8,5" and "5,8,3,1" are both suitable. The direction can, however affect the definition of the top flange (see also Flange restraints). Consider, for example, a simply supported beam with a node at each end which is subjected to an axial compressive force and a uniformly distributed dead load. When analysed, the deflected shape and bending moment distribution along its length is calculated by SPACE GASS. If the structural adequacy of this member is then checked against one of the design codes, various factors are calculated based on the deflected shape and the bending moment distribution. These factors are then used in the calculations to determine if the member is adequate or not. If the same beam is modelled with a third node at midspan, you would still get the same deflected shape and bending moment distribution, however unless you were able to group the two halves of the beam together and design them as though they were a single member you would get a completely different design result. This is because the factors and the combined actions moments and axial forces would be based on the deflection and moment distributions for only half of the beam rather than its full length.

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Steel Member Design

If a member has been subdivided into smaller members in the analysis model, it is important that these sub-members are grouped together in the design model. The rules for deciding whether or not a run of frame analysis members should be grouped into a design group are as follows. 1.

Each member in a design group must be rigidly connected to each other end-toend, they must lie generally in a straight line, and they must have the same section properties.

2.

The length of a design group should not be less than the major axis span.

3.

A design group must be long enough to include all of the flange restraints that affect its bending effective lengths. Furthermore, under no circumstances should the design group length be less than the unrestrained lengths of the top and bottom flanges. This rule is not applicable if the bending effective lengths are specified directly rather than being calculated.

4.

Each end of a design group should coincide with the physical end of a member or a significant change in direction of a member, or a support point for a member. It shouldn’t normally extend past a support or past an intersecting member that effectively acts as a support. "Support" refers to a support for the major axis span.

If it is not possible for all of the above rules to be satisfied then you should not use SPACE GASS to design the steel members involved. Consider the following examples, indicating how members in typical frames can be grouped together.

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Member grouping for gable portal

Group 1: Group 2: Group 3: Group 4:

1,2 3,4,5 6 7,8

Member grouping for flat portal

Group 1: Group 2: Group 3:

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1,2 3,4,5,6 7,8

Steel Member Design

Member grouping for truss

Group 1: 2,6,10,14,18,22 Group 2: 4,8,12,16,20,24 Group 3: 1 Group 4: 3 (Some of the non-critical members have not been grouped) ! IMPORTANT NOTE ! The above grouping assumes that local bending of the chords between panel points is insignificant compared with overall bending between the end supports (ie. the panel points are not really acting as support points for the chords). If the chords were effectively spanning L/6 instead of L then the chord members could not be grouped.

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Member grouping for multi-storey frame

Group 1: Group 2: Group 3: Group 4: Group 5: Group n: etc...

1 2 3 4 5 n

No grouping of multiple members can occur in this case because each member acts as a single span. The horizontal beams act as supports for the columns at each floor and the columns act as supports for the beams. Note that, if there was no significant axial forces in the beams such that they were not acting as supports for the columns then the columns could be grouped into one design group from bottom to top. This would not, however be a common situation.

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Steel Member Design Member grouping for continuous beam

Group 1: Group 2:

1,2,3,4 5,6

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Flange restraints Flange restraints must be specified for both top and bottom flanges at each end of a design group and at each intermediate restraint position.

Because the positions of the start and finish flange restraints is known, only the intermediate restraint positions should be specified. However, the end and intermediate restraint types should be specified. The top flange of a member is the flange on the positive local y-axis (or z-axis if the section has been flipped) side of the member. The top flange of a group as a whole is defined such that it is the same as the top flange of the first member in the group. You can verify graphically which is the top flange by clicking the button near the bottom of the side toolbar. It displays a small triangle that points to the top flange of each member. There are two classes of restraint types; those that occur at a discrete point and those that occur over a continuous length of flange between two point restraints. The number of point restraint types should exactly match the number of restraint positions. When @ multipliers are used in the restraint positions lists, the corresponding restraint types must have only one character for each @ multiplier. For example, restraint positions of 1.2,2.4,3.6,4.8,6.0,6.6,7.2,7.8,8.4 with corresponding restraint types of LLLLLPPPP could be specified as [email protected],[email protected] and LP. If the restraint types were LLPLLPPPP, however then they would have to be specified as [email protected],3.6,[email protected],[email protected] and LPLP. SPACE GASS accepts six point flange restraint types and two continuous flange restraint types. They are defined as follows. Note that these definitions are slightly different to the ones in the design codes because the code definitions apply to the cross section rather than to each flange. The cross section restraints are determined from the flange restraints during the design or check phase. Full restraint (F)

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Prevents lateral deflection of the flange to which it is applied and fully prevents twist rotation of the section.

Steel Member Design

Partial restraint (P)

Prevents lateral deflection of the flange to which it is applied and partially prevents twist rotation of the section.

Lateral restraint (L)

Prevents lateral deflection of the flange to which it is applied but is ineffective in preventing twist rotation of the section. A lateral restraint can only be considered to be effective when it is positioned between full or partial restraints.

Full & rotational restraint (R)

The same as full restraint above but also with significant restraint against lateral rotation of the flange about the cross section’s minor axis.

Partial & rotational restraint (S)

The same as partial restraint above but also with significant restraint against lateral rotation of the flange about the cross section’s minor axis.

Unrestrained (U)

There is no resistance to lateral deflection of the flange to which it is applied or twist rotation of the section. This can only be used at the end of a design group.

An "unrestrained" end does not necessarily imply a cantilever. Flange restraints are independent of the member support system. Cantilevers or beams with supported ends could be restrained or unrestrained. The following flange restraint types do not occur at a point but are continuous between two adjacent point flange restraints. Continuous lateral restraint (C)

Prevents lateral deflection of the flange to which it is applied but is ineffective in preventing twist rotation of the section. A continuous lateral restraint can only be considered to be effective when it is positioned between full or partial

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SPACE GASS 12 User Manual restraints. Ignore segment (I)

This is not really a flange restraint, rather it instructs SPACE GASS to skip past the ignored segment length when designing or checking. It can be used very conveniently to ignore the very rigid area where intersecting members connect so that members are designed from the face of intersecting members rather than from their centrelines. It is also very handy for when a member is stiffened over part of its length and is not required to be designed over that portion.

The above definitions allow for full, partial, lateral or no restraint against twist of the cross section (about its longitudinal axis) (F,P,L,C or U). They also allow for full or no restraint against lateral rotation of the critical flange (about the minor cross section axis) in the presence of full or partial twist restraint (R or S). An extra restraint condition which is catered for in AS1250, SABS0162, BS5950, AS3990 and HK CP2011 only, that provides partial restraint against lateral rotation of the critical flange is not supported by SPACE GASS.

For single angle sections, it is unclear whether or not lateral restraints applied to either leg are effective in providing any restraint to the section. Consequently, you should be very careful when applying lateral restraints to single angle sections and you should use them only if you are sure they are effective in restraining the section. SPACE GASS will apply them if you specify them and so the decision about whether or not they should be used is entirely up to you. Note that the design/check calculations are based on the effective cross section restraint rather than the restraint on a particular flange. The effective cross section restraint depends on which flange is the critical one and on what flange restraints are applied to the critical and the non-critical flanges. Refer to "Effective flange restraints" for more information. The following diagrams are a collection of some fairly typical support and fly brace connection details. The type of restraint that applies to each flange is shown as either "full", "partial", "lateral" or "unrestrained". Note that the diagrams apply

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Steel Member Design regardless of whether or not rotational restraints also exists. The terms "full" or "partial" could also read "full and rotational" or "partial and rotational" in each of the diagrams.

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Flange restraint types

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Steel Member Design Consider, for example, the portal frame below. The roof bracing system laterally braces each rafter at the eaves and apex. Purlins are positioned at ninth points along each rafter and fly braces are attached to each third purlin at rafter third points. Girts are positioned at the mid-height of each column.

Portal frame flange restraints

We will assume that the roof sheeting has enough rigidity to allow the purlins to prevent lateral deflection of the rafter top flange. Note that if the roof sheeting has insufficient rigidity to prevent lateral deflection then the fly braces will not be capable of providing any restraint to the bottom flange and will thus be totally ineffective.

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SPACE GASS 12 User Manual The frame could be set up with four design groups, each containing the following members. Group 1: Group 3: Group 6: Group 7:

1,2 3,4,5 6 7,8

When determining flange restraint positions and types, we will assume that the footing, eave and apex connections provide F (full) restraint to both flanges of each member framing into them. There is no fly bracing attached to the wall girts and they provide lateral restraint only to the outside flange of the columns. Thus, groups 1 and 7 have top flange restraints of F (full) at each end and L (lateral) at mid height, and bottom flange restraints of F (full) at each end only. If there had been fly bracing to the girts then there would also be a bottom flange mid height restraint of L (lateral). Note that the top flange for groups 1 and 7 is the outside flange because the local y-axis for members 1, 2, 7 and 8 points towards the outside of the frame. Similarly, groups 3 and 6 have top flange restraints of F (full) at each end and L (lateral) at each purlin, and bottom flange restraints of F (full) at each end and L (lateral) at each fly brace location. Thus, the restraint arrangements for the frame are: Groups 1 and 7: FLF FF Groups 3 and 6: FLLLLLLLLF FLLF

(Outside flange) (Inside flange) (Top flange) (Bottom flange)

Note that by applying L (lateral) restraints to both flanges at each fly brace location we are assuming that the purlins are flexurally stiff enough to fully prevent twist rotation of the rafter. If they can only partially prevent twist rotation of the rafter then the group 3 and 6 restraints would become FLLPLLPLLF on the top flange and FF on the bottom flange. Restraint Forces The brace, purlin, girt or other member that provides full, partial or lateral restraint to the critical flange of a member must be capable of resisting the force required to provide such restraint. This is not automatically allowed for in the analysis or design. If you wish to take this into account then you should add the restraint forces

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Steel Member Design to your applied loads. The restraint forces are code specific and you should refer to the appropriate clauses for the design code you are using. This effect is particularly important for deep beams where the forces required to restrain the critical flange can be quite high. You should check that your model is capable of withstanding these forces.

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Column and beam Tees Column Tees have the major axis parallel to the web and are therefore assumed to be lying on their side with their flange vertical (assuming a zero direction angle and no flipping). They are orientated at right angles to normal beam Tees which have the major axis parallel to the flange.

Tee section orientation

Note that although beam Tees are supported by all of the steel member design modules, only the AS4100, NZS3404, AISC-ASD, AISC-LRFD, EUROCODE 3, HK CP2011 and BS5950 modules support column Tees. See also Steel member design sign conventions.

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Steel Member Design

Running a steel member design You can run a steel member design or check by selecting one of the "Steel Member Design/Check" items from the Design menu.

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Steel Member Design AISC-LRFD, EUROCODE 3, AS4100, NZS3404, BS5950 and HK CP2011 require second order effects to be taken into account by either performing a first order (linear) elastic analysis with moment magnification or a second order (non-linear) elastic analysis with no moment magnification. Because a nonlinear analysis is generally more efficient and accurate than moment magnification, and because SPACE GASS has no facilities for moment magnification, it is recommended that a non-linear analysis be used at all times for these codes. Design / Check mode You can select between design mode or check mode as follows. 1. Design mode Works its way up from the smallest library section that conforms with the specified library scan code until it finds a section that passes the code requirements for the design group being designed.

2. Check mode Just checks the section from the analysis data for the design group being checked. Note that SPACE GASS can now do a steel member check using sections that haven't been imported from a library, however you must have specified their steel design properties via the Shape builder. Member groups list If you want to consider all design groups (for which steel member design data has been input) then this field can be left blank, otherwise you should type in a subset of design groups (separated by commas or dashes). Section properties list If you want to consider all design groups (or a subset as specified above), regardless of section type, leave this field blank. Otherwise, type in a list of section property numbers (separated by commas or dashes) to limit the number of design groups. For example, if the columns in a frame all have section property number 3, you could instruct the program to design only the columns by entering "3" in the section properties list. Alternatively, you could type in all of the groups containing columns in the member groups list above, however this would be much more cumbersome.

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SPACE GASS 12 User Manual Load cases list If you want to consider all load cases then this field can be left blank, otherwise you should type in a list of incorporating the load cases (separated by commas or dashes) that you want considered. Default section library During the frame analysis section property input phase, sections that are read from a library have the library name stored with their section property data. Sections that have not been read from a library do not have a library name stored with their data. For members with analysis section properties that were read from a library, the steel member design module uses that library to get information about the strength grade, properties, cross section shape, etc. of the member. For members with analysis section properties that were not read from a library, the design module uses the default section library to get its information. Intermediate stations per member During the design process, each analysis member in a design group is subdivided into small increments using intermediate member stations. You must define the number of equally spaced intermediate stations that are to be positioned along each analysis member. SPACE GASS automatically adds an extra station at each end of an analysis member, at each point of application of a concentrated member load, at each flange restraint position, and at the quarter points between flange restraints. If a design group consists of more than one analysis member then the member stations are simply added together to give a total number of stations for the design group as a whole. The member stations are the points at which deflections, forces and moments are calculated. They are also the points at which code checks are carried out. It is therefore important that there are enough stations located along the design group to give a good representation of the deflected shape, bending moment diagram and shear force diagram so that the design results are accurate. 9 intermediate stations for each analysis member is normally quite accurate, however this can be increased to 75 if required. Note that the speed of the design process is approximately proportional to the number of stations per design group.

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Steel Member Design Compression effective length ratio limit Because the compression effective lengths from a buckling analysis can sometimes be overestimated, you can specify an upper limit that will be imposed during the design phase. Compression effective lengths from a buckling analysis are limited to Ratio x GLen, where Ratio is the compression effective length ratio limit that you specify and GLen is the overall design group length. Note that this limit applies only to compression effective lengths from a buckling analysis and not to those specified directly. See also Buckling effective lengths. Load factor limit or Combined stress ratio limit Firstly, the terms "load factor" and "combined stress ratio" are defined as follows. The load factor applies only to AISC-LRFD, EUROCODE 3, AS4100, AS4600, BS5950, NZS3404 and HK CP2011. It is the amount by which the design actions can be increased before the point of failure is reached. For example, if the steel design returns a load factor of 1.12, you could theoretically increase your loads by 12%, repeat the analysis and design, and expect the load factor to reduce to 1.00. This is not always the case however, because the non-linearity of the analysis means that increasing your loads by 12% does not guarantee that the design actions will also increase by exactly 12%. For members designed in accordance with these codes, the load factor must be greater than 1.0. This means that the design actions can be factored up by an amount greater than 1.0 before the member becomes inadequate.

Because the relationship between design actions and design capacity is not linear, the load factor is not equal to the inverse of the (design actions)/(design capacity) failure equation at the end of the detailed calculations for each member in the steel design report. The combined stress ratio applies only to AISC-ASD, AS1250, SABS0162 and AS3990. It is the ratio of the actual stresses to the permissible stresses for the governing combined stress equation.

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SPACE GASS 12 User Manual For members designed in accordance with AISC-ASD, AS1250, SABS0162 or AS3990, the combined stress ratio must be less than 1.0. This means that the combined stresses in the member are less than the combined permissible stresses. During the design process, if the load factor is slightly less than 1.0 or if the combined stress ratio is slightly greater than 1.0, the member is deemed to have failed. In a real design situation however, you may decide to accept members which are very slightly overloaded. In order to cater for this reality, SPACE GASS allows you to decrease the load factor limit or increase the combined stress ratio limit so that the design program can accept a small amount of overload. Alternatively, you can increase the load factor limit or decrease the combined stress ratio limit if you wish to design conservatively. Slenderness ratio limit This setting affects a simple slenderness ratio check that is only applicable to AISC-ASD, AISC-LRFD, AS1250, AS3990 and SA0162. The other codes have more sophisticated slenderness checks built into their standard equations. For the applicable design codes, recommendations for maximum slenderness ratios range from 180 to 300 for struts, 300 to 350 for ties and 250 to 300 for beams. The maximum values depend on various factors including whether the predominant load is due to wind or not. For tension members and members that have zero axial load, there is no slenderness check for compression effective lengths, however there is a slenderness check for bending effective lengths. Because of this, you may notice that in some cases the output report shows a value of l/r (compression) which exceeds the permissible l/r ratio without the member failing. Interrupted check (check mode only) If the checking procedure is uninterrupted, then after each member check, the results are saved and the program moves on to the next member regardless of the outcome of the check. Using this procedure, it is possible to check a large numbers of members without any operator intervention. Alternatively, you can elect to have interrupted checking which causes the program to stop after each member check, notifying you of the results of the check and allowing you to manually select other member sizes for checking. If you decide not to try other member sizes, the program saves the results of the check and moves on to the next member.

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Steel Member Design Equalizing the design sizes for matching analysis sections SPACE GASS allows you to specify that all members with the same analysis section property number should finish up with the same section size in the design results. Note that this only applies to running the steel member design module in "design" mode. For example, consider a portal frame with one analysis section for the two columns and another for the two rafters. When you perform a steel member design (as opposed to a check), you can specify that because the two columns share the same analysis section property number, their final design sizes should also match. Similarly, the two rafters can also be kept equal on each side because they share a single analysis section property number. If this option is not selected, the design module will design each member independently rather than matching a single section size to all members that share the same analysis section property number. For the portal frame example mentioned above, this could results in four different member sizes rather than two. Adjustment of minor axis compression effective lengths Flange restraints capable of preventing lateral buckling of the flanges are sometimes also capable of preventing lateral buckling of the overall cross section. This depends on the type of the flange restraint and on the shape of the cross section and, if applicable, means that the minor compression effective length can be reduced to the length of the segment under consideration. This happens regardless of whether the compression effective lengths are calculated from a buckling analysis or specified directly. If you select the "Adjust based on flange restraints generally" check box, the minor compression effective length will be adjusted if: a. both ends of the segment have full or partial flange restraints; or

b. both ends of the segment have full, partial or lateral flange restraints and the member is a tube or box section. If you also select the "Adjust for L restraints on equal flanged I or W shapes" check box then condition (b) above will also be extended to apply to equal flanged I or W shapes. Note, however, that there is some recent doubt as to whether lateral restraints on equal flanged I or W shapes can restrain the overall cross section laterally and therefore this check box defaults to off. See also Buckling effective lengths.

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SPACE GASS 12 User Manual Consider eccentric effects Members such as angles, channels and Tees are sometimes connected at their ends by one flange or plate only. Depending on the shape of the section and the distance from the point of connection to the centroid of the section this can induce eccentric moments into the member. This check box only affects the design groups that have eccentric effects enabled in their design input data. For design groups that have their individual eccentric effects disabled, this check box setting has no effect. See also Eccentric effects for compression members. See also Eccentric effects for tension members. Convert single angle compression effective lengths For single angle sections, the compression effective lengths must be input relative to the non-principal axes. These lengths are normally converted to principal axes during the design phase if required, however you can prevent this by unticking the "Convert single angle compression effective lengths" option. One reason for this might be that you have already input the compression effective lengths in principal axes and you don't want them to be converted. Use Kt factor for tension members When considering eccentric end connection effects, the extra eccentric moments are usually calculated and then added to the other bending moments in the member. For tension members with AS4100/NZS3404, however the code allows you to use the above approach or simply ignore the extra eccentric moments and apply a correction factor (Kt) which is based on the cross section shape and the location of the point of connection (see AS4100/NZS3404 clause 7.3.2). By default the steel member design module defaults to using the Kt factor because it tends to give a more economical design in most cases, however you can elect to use the eccentric moments approach instead if you wish. See also Eccentric effects for tension members. Other factors Various other factors can also be defined depending on the design code being used. They include AISC-ASD and AISC-LRFD U and Cb factors, Eurocode UK and Dutch factors, an AS4600 appendix F switch and HK CP2011 mLT factors.

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The HK CP2011 module also allows you to choose between using clause 8.9.2 or clause 6.8.3. If you choose clause 8.9.2 then the analysis does not need to include initial member imperfections or P- effects because they are accounted for in the design phase (although it may be prudent for you to use both P- and P- effects in the analysis anyway). Alternatively, if you choose clause 6.8.3 then you must include initial member imperfections and both P- and P- effects in the analysis. Frame and Member Imperfections Most design codes require you to include initial frame and member imperfections in the analysis. The analysis module does not do this automatically and so you must build the required imperfections into your model. Frame imperfections can be modelled by applying notional horizontal forces or initial deflections to nodes. Member imperfections can be modelled by applying initial curvature to members. These must both be done in accordance with the relevant clauses of the design code you are using.

When all of the information has been entered, the SPACE GASS steel member design/check proceeds. If you want to terminate the process before it is finished, just press ESC or the right mouse button. If you terminate the process in this way, the results for any groups that have already been designed or checked are saved.

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Updating analysis member sizes The accuracy of any steel member design is dependent on the accuracy of the analysis on which it was based. A truly accurate design can only be obtained when the design member sizes agree with those used in the preceding analysis. SPACE GASS has the ability to iterate the analysis-design process until the results converge. The design sizes can then be printed out and used in the final computations. You can access the updating tool by answering "Yes" to the "Do you wish to update the analysis section properties with the new design member sizes?" question at the end of a steel member design or by selecting "Update Analysis Member Sizes" from the Design menu. Note that this tool only works if you have run the steel member design module in design mode (as opposed to check mode).

After an initial design, you can use this tool to update the analysis section property data based on the new design member sizes. You can also re-run the analysis and design modules, and automatically iterate the entire update-analysis-design process until the analysis and design member sizes match. If a buckling analysis is included in the iterative procedure, after the updateanalysis-design procedure has finished, if the lowest buckling load factor is less

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Steel Member Design than the value you specify in the above form, a warning is given. Keep in mind that you may want to adjust the buckling load factor warning threshold depending on whether you are analysing working loads or factored loads.

The iterative procedure does not currently include re-running the dynamic analysis modules. Hence, if your steel member design is based on some dynamic response analysis results, you must re-run the dynamic analysis manually for each iteration.

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Serviceability check The SPACE GASS steel member design module does not consider serviceability requirements other than slenderness effects during the course of a design or check. This is because there are numerous ways to limit excessive deflections, many of which require extensive engineering judgement. The only deflections that can easily be checked for adequacy by an automatic design program such as SPACE GASS are the local member deflections that apply to each member individually. It is quite appropriate to check local member deflections for simple beams and columns, however for sway frames and for members that have been subdivided into smaller segments, the local member deflections become meaningless. Take for example a portal frame building that is found to have excessive lateral sway deflections. The deflections could be reduced in many ways such as by increasing the size of the columns, increasing the size of the rafters, introducing a haunch, increasing the size of the haunch, adding extra roof and end wall bracing or by adding an external restraint such as brickwork. The optimum method in controlling deflections is determined often by architectural constraints, cost constraints, engineering preferences and other constraints that are not immediately obvious to a design program. Some of these parameters could possibly be built into SPACE GASS, however the extra data required to be input would make the program very cumbersome and unwieldy compared to the method recommended in the following paragraph. In order to satisfy serviceability requirements, it is recommend that the frame first of all be designed to satisfy strength requirements. This includes the initial design and subsequent analysis-design iterations (see also Updating analysis member sizes). It is then a simple matter to obtain a graphical display or printout of the deformed geometry shape and simply observe whether the frame has excessive deflections or not. If the deflections are excessive, you can increase member sizes manually or add bracing as required, followed by another analysis and obtain a revised deformed geometry display. If the deflections are satisfactory it is then a matter of performing a final code check to ensure that the changes have not caused any members to become inadequate.

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The steel member design/check process This section describes in detail the internal procedures and assumptions used as the program calculates the capacity of a design group and determines whether it is adequate or not. Because the procedure is very similar for all codes, you can assume that all of the discussion in this section applies equally to all codes unless specifically stated otherwise. The steps involved in a design are the same as those for a check except that a design tries various member sizes until it finds one that is adequate, while a check simply tries a single member size only and saves the results regardless of whether it is adequate or not. This process is repeated separately for each design group.

In the remainder of this section, the process of trying a member size for compliance with one of the steel codes will be referred to as "checking" regardless of whether it is done as part of a steel member design or a steel member check.

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Design groups and intermediate stations The analysis members that make up the design group are assembled together into one complete design member. The intermediate member stations for each analysis member are positioned along the design group and then for each flange additional stations are positioned at the points of flange restraints and at quarter points between adjacent flange restraints. For each load case being considered, the deflections, forces and moments are calculated at each station along the entire design group. For single angle sections, they are calculated relative to the cross section principal axes for AS4100, BS5950, NZS3404, AS4600, AISC-LRFD and AISC-ASD, and relative to the non-principal axes for AS1250, SABS0162, AS3990, EUROCODE 3 and HK CP2011.

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Design segments The program begins working its way along the design group until it gets to the end of a segment. A segment end occurs at the start of the design group, at the end of the design group, and wherever a full, partial or lateral flange restraint has been applied to the critical flange. Thus the current design segment is the portion of the design group that extends from the current critical flange restraint location back to the end of the previous design segment (or start of the design group). For each station in the segment, the program does a cross section capacity check using the forces and moments which occur simultaneously at that point. It also does various member checks for the segment as a whole using all possible combinations of maximum forces and moments that occur anywhere in the segment.

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Section check A section check simply considers the capacity of a cross section and is not related to effective lengths or any other conditions that occur away from the cross section. The forces and moments used are those which occur simultaneously at the cross section.

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Member check A member check considers the capacity of a member segment. The member check is affected by the compression and bending effective lengths of the segment and the shape of the deflection and bending moment diagrams along the segment. The forces and moments used in a member check are the maximum values taken from anywhere along the segment.

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Critical flange The critical flange at any point within a segment is assumed to be the compression flange unless either end of the segment is laterally unrestrained in which case it is assumed to be the tension flange.

SPACE GASS is not able to determine whether a loading condition is predominantly due to gravity or wind and you should therefore check that the above rule is valid for your situation. For more information refer to AS1250 clause 3.3.4.7, AS4100 clause 5.5, SABS0162 clause 7.2.3, BS5950 clause 4.3, NZS3404 clause 5.5, AS3990 clause 3.3.4.7 or HK CP2011 clause 8.3.

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Effective flange restraints In the following discussion, the "segment length" is the distance between two adjacent cross sections that are restrained or between a cross section that is restrained and the end of the design group. A cross section is assumed to be restrained when a full or partial restraint is applied to either flange or when a lateral restraint is applied to its critical flange.

Member design segments

The design group in the diagram above consists of three analysis members of different lengths. The group has full or partial restraints at the ends and three equally spaced lateral restraints on the top flange. For the bending moment diagram shown, the first top flange lateral restraint is ineffective because the bottom flange is the critical flange at that point. Thus, the first segment continues past the first top flange restraint to midspan where the top flange has become the critical one. When determining the effective restraint at a cross section, SPACE GASS looks at the restraint applied to the critical flange, however it also looks at the other flange to see if a restraint has been applied to it and, if so, whether or not it affects the cross section restraint. Thus, the effective restraint for the cross section can be dependent on the restraint applied to both flanges. In the following table, the "critical flange" is as per the critical flange definition, the "other flange" is the non-critical flange and the "effective restraint" is the cross section restraint that SPACE GASS uses in the code check.

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For restraint type definitions see also Flange restraints. A C (continuous) flange restraint is assumed to be equivalent to a series of L (lateral) flange restraints spaced at increments of 1mm for the entire length of the continuous restraint. Restraint on Critical Flange None or U L P or F S or R None or U None or U None or U L, P or F S or R

Restraint on Other FlangeEffective Restraint None or U None None or U L None or U F None or U R L None P or F P S or R S L, P, F, S or R F L, P, F, S or R R

For single angle sections, it is unclear whether or not lateral restraints applied to either leg are effective in providing any restraint to the section. Consequently, you should be very careful when applying lateral restraints to single angle sections and you should use them only if you are sure they are effective in restraining the section. SPACE GASS will apply them if you specify them and so the decision about whether or not they should be used is entirely up to you.

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Steel Member Design

Twist factor The twist factor kt depends upon the flange restraint conditions and the cross section shape. If the critical flange switches from top to bottom within the segment, the critical flange thickness is assumed to be the thickness of the flange at the end of the segment. For AS4100 and NZS3404, kt is calculated from table 5.6.3(1), while for AS1250, SABS0162, BS5950, HK CP2011, EUROCODE 3 and AS3990 it is taken as 1.0.

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Load height factor The load height factor kl relates to the point of application of gravity loads as specified by the load height position (see also "Load height position" in Steel member design data). It is always 1.0 if the loads are applied at or below the member's shear centre, however for non-vertical members it can exceed 1.0 if the top of the member is subjected to a downwards load that causes a destabilizing effect.

If the top of the member is loaded within the segment then kl = 1.2 for all codes, except AS4100 and NZS3404 where kl = 1.4 if both ends of the segment are fully, partially or laterally restrained or kl = 2.0 if either end is unrestrained. If the top of the member is not loaded within the segment but shear force is detected at the end of a segment that is unrestrained then kl = 1.2 for all codes, except AS4100 and NZS3404 where kl = 2.0. If you specify the load height position as "Shear centre" then kl=1.0 regardless of the loading condition. For vertical members, kl=1.0 regardless of the load height position setting or the loading condition.

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The definition of "top of the member" in the above discussion is the side or flange that is physically on top (ie. furthest from the ground). This definition is different to "top flange" used elsewhere in this manual which can actually be on the bottom if you have rotated the member about its own axis (eg. if the member is upside down).

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Lateral rotation factor The lateral rotation factor kr is based solely on the flange restraint conditions. Its value for some codes is given in the following table. The restraint codes given represent the flange restraints at each end of the segment under consideration. For example, PP represents partial restraint at both ends, while PF represents partial restraint at one end and full restraint at the other end. End Restraints RR SR FR PR LR UR SS FS PS LS US FF PF LF UF PP LP UP LL UU

AS3990/ AS1250 0.70 0.77 0.85 .935 1.00 .935 0.84 .935 1.02 1.00 1.02 1.00 1.10 1.00 1.10 1.20 1.00 1.20 1.00 1.20

AS4100 0.70 0.70 0.85 0.85 1.00 1.00 0.70 0.85 0.85 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

SABS0162 0.70 0.77 0.85 .935 1.00 .935 0.84 .935 1.02 1.00 1.02 1.00 1.10 1.00 1.10 1.20 1.00 1.20 1.00 1.20

NZS3404 0.70 0.70 0.85 0.85 1.00 1.00 0.70 0.85 0.85 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

The values of kr in the table are taken from AS1250 clause 5.9, AS4100 table 5.6.3(3), SABS0162 clause 7.2.3, BS5950 clause 4.3.5, NZS3404 table 5.6.3(3) and AS3990 clause 5.9. There are some specific assumptions affecting kr which you should be aware of, as follows: 

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AS1250, SABS0162, BS5950, HK CP2011 and AS3990 do not give specific rules for calculating kr for all combinations of flange restraints at the ends of the

Steel Member Design segment. In such cases interpolation has been used to calculate some of the values of kr given in the table. 

The extra restraint condition in AS1250, SABS0162, BS5950, HK CP2011 and AS3990 which provides partial restraint against lateral rotation (about the cross section minor axis) of the critical flange is not supported in SPACE GASS.



Because it is difficult for SPACE GASS to determine whether a member is a true cantilever or not, AS1250 clause 5.9.4, SABS0162 clause 7.2.3(b), BS5950 clause 4.3.5.4/4.3.5.5, HK CP2011 clause 8..4.3 and AS3990 clause 5.9.4 have not been considered. This may cause the bending effective length for cantilevers to be underestimated and you should therefore check the bending effective length for cantilevers calculated by the AS1250, SABS0162, BS5950, HK CP2011 and AS3990 modules.

Before accepting the bending effective length calculated by SPACE GASS, it is recommended that you verify for yourself that the values of kr given in the previous table are a suitable interpretation of the code that you are using.

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End moment ratios and other factors During a member check, various factors are calculated. In most cases, these factors are largely dependent on the moments at the ends of the segment under consideration. Some of them, however depend on the values of moments and/or displacements at mid or quarter points along the segment. It is not always possible to have stations positioned exactly at the mid or quarter points required because even though stations are positioned at mid and quarter points between adjacent flange restraints, segments do not always extend between adjacent flange restraints (particularly when the critical flange changes due to moment reversal). In such cases, SPACE GASS simply takes the moment and/or displacement values from the station nearest to the required point. For the AS4100 and NZS3404 modules, m is calculated using the formula in clause 5.6.1.1(a)(iii) when the segment is restrained at both ends. If the segment is unrestrained at one end, AS4100 and NZS3404 require the bending moment diagram to be matched to one of the three diagrams shown in table 5.6.2. This is very difficult when the bending moment diagram could be any conceivable shape. Therefore, SPACE GASS adopts a slightly conservative approach and uses m = 1.0 when there is no moment at the unrestrained end or m = 0.25 when there is a moment at the unrestrained end.

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Steel Member Design

Eccentric effects for compression members Eccentric end connection effects for angles, channels and Tee sections subjected to axial compression are normally taken into account by calculating the extra eccentric moments and then adding them to the normal design moments along the entire length of the design group (unless they cause a net reduction in the final design moment). For all codes, the eccentric moments are calculated by multiplying the axial force by the distance from the centroid of the connected plate to the centroid of the cross section.

Eccentric effects for compression members can be suppressed if required.

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Eccentric effects for tension members Eccentric end connection effects for angles, channels and Tee sections subjected to axial tension are taken into account in various ways depending on the design code being used. For AS1250, SABS0162 and AS3990, SPACE GASS simply calculates the extra eccentric moments and then adds them to the normal design moments along the entire length of the design group provided that they don’t cause a net reduction in the final design moment. This method is used instead of reducing the effective area of the cross section in accordance with AS1250 clause 7.3.2, SABS0162 clause 9.2 or AS3990 clause 7.3.2. The AS4100 and NZS3404 modules also use the above method of calculating and adding eccentric moments if the Kt method is not used. Alternatively, if the Kt method is used then Kt is calculated in accordance with AS4100/NZS3404 clause 7.3.2 and used to reduce the member tensile capacity rather than eccentric moments being added. The Kt method also applies to I, H or channel sections which are connected by their flanges only. For these sections, SPACE GASS assumes that the provisions of AS4100/NZS3404 clauses 7.3.2(b)(i) and (ii) have been met and uses Kt = 0.85.

Eccentric effects for tension members can be suppressed if required.

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Steel Member Design

The code check When all of the member properties, effective lengths, design loads and other factors have been calculated, they are fed into the appropriate code specific subroutines to determine the success or failure of the code check. During this process the subroutines also calculate the load factor or the combined stress ratio which is then passed back to SPACE GASS along with many other design result parameters. If the latest check is more critical than any previous checks for the design group then the results of the latest check are retained as the governing case until another check further along the design group yields a smaller load factor or a larger combined stress ratio. After considering every segment in the design group for each design load case, SPACE GASS saves the data for the governing section and member check cases and moves on to the next design group.

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Steel member design results At the end of a steel member design or check, you can produce a full report showing the results of the design or check. The pass/fail status of each member can also be shown graphically in a color-coded display as described in "View steel member design results". Filters can also be created to filter members in accordance with their pass/fail status as described in "Filters". You can also query individual members graphically to get an abbreviated report showing the results of the design or check as described in "Query steel member design results".

Reports for single angle sections are in principal axes for AS4100, BS5950, NZS3404, AS4600, AISC-LRFD and AISC-ASD. Updating analysis member sizes If you have performed a design (as opposed to a check), the final design member sizes are probably slightly different to those in the analysis section property data. So that the design is based on the same member sizes as the analysis, the new design member sizes should be transferred back into the analysis and then the analysis and design process iterated until the analysis and design sizes are the same. This is described in detail in "Updating member sizes". Member, section and shear checks For each steel design member in a full report, three lines of information relating to section, member and shear checks are presented. These represent summaries of the results of the three main checks that are performed when a steel member is designed or checked. The section and shear checks are performed at numerous points along each design group. They consider the capacity of a cross section and are not related to effective lengths or any other conditions which occur away from the cross section under consideration. The forces and moments used in a section or shear check are the ones which occur simultaneously at the cross section. The governing location for the section and shear checks is shown under the "Start Pos’n" heading.

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Steel Member Design The member check is performed for each segment between adjacent points of critical flange restraint. The member check is affected by the axial and bending effective lengths of the segment and the shape of the deflection and bending moment diagrams along the segment. The forces and moments used in a member check are the maximum values taken from anywhere along the segment. The governing segment for the member check has its start and finish locations shown under the "Start Pos’n" and "Finish Pos’n" headings. Load factor The load factor applies only to AISC-LRFD, EUROCODE 3, AS4100, AS4600, BS5950, NZS3404 and HK CP2011. It is the amount by which the design actions can be increased before the point of failure is reached. For example, if the steel design returns a load factor of 1.12, you could theoretically increase your loads by 12%, repeat the analysis and design, and expect the load factor to reduce to 1.00. This is not always the case however, because the non-linearity of the analysis means that increasing your loads by 12% does not guarantee that the design actions will also increase by exactly 12%. For members designed in accordance with these codes, the load factor must be greater than 1.0. This means that the design actions can be factored up by an amount greater than 1.0 before the member becomes inadequate.

Because the relationship between design actions and design capacity is not linear, the load factor is not equal to the inverse of the (design actions)/(design capacity) failure equation at the end of the detailed calculations for each member in the steel design report. Zero variables in reports You may notice that some variables in the steel member design output report are shown as zero when it appears that they should have a non-zero value. This occurs because the steel member design modules only calculate the values that are applicable to the design actions and section type. Variables which are not applicable for the governing failure mode are not calculated and hence appear as zero in the output report.

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Steel member design/check assumptions This section lists the main assumptions that are made in the steel member design module. Some of these assumptions are also described in the previous sections of this chapter and others are listed only in this section. It is up to you to check that these assumptions are suitable for your situation. Note that some of the following general assumptions may be overridden by the code specific items listed in the sections immediately following this one. 1. Frame imperfections are not automatically allowed for during the design phase. When applicable (usually for multi-storey frames), you should apply notional horizontal forces or initial deformations to the analysis model in accordance with the requirements of the design code. 2. The top flange of a member is the flange on the positive local y-axis (or zaxis if the section has been flipped) side of the member. The top flange of a member can be easily determined by displaying the member local axes graphically and observing the direction of the local y-axis (or z-axis if flipped). 3. The top flange of a group as a whole is defined such that it is the same as the top flange of the first member in the group. 4. The critical flange at any point within a segment is assumed to be the compression flange unless either end of the segment is laterally unrestrained in which case it is assumed to be the tension flange. SPACE GASS is not able to determine whether a loading condition is predominantly due to gravity or wind and you should therefore check that the above rule is valid for your situation. 5. All section and member capacities are calculated assuming that stiffeners do not exist. 6. The AS4100, AISC-LRFD, BS5950, EUROCODE 3, HK CP2011 and NZS3404 modules assume that second order effects have been taken into account by a second order elastic analysis. Moment magnification is not considered. 7. The AS4100, AISC-LRFD, BS5950, EUROCODE 3, HK CP2011 and NZS3404 modules assume that the design load cases are factored

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Steel Member Design (ultimate). 8. The NZS3404 module uses the "Other than capacity" design method with non-seismic ductility categories only. 9. For single angle sections, the effective lengths and flange restraints must be input relative to the non-principal axes. For all other sections, they must be input relative to the principal axes. 10. The compression effective lengths Lmx and Lmy, used by AS4100 and NZS3404 in clause 8.4.2.2 for the calculation of Nc when ke=1.0, are assumed to be equal to the lesser of the total design group length and the normal compression effective lengths for the segment under consideration. Lmx = MIN(Ltot,Lcmajor) and Lmy = MIN(Ltot,Lcminor), where Ltot is the total design group length and Lcmajor and Lcminor are the normal compression effective lengths. 11. The torsion effective length used by AS4100 and NZS3404 is assumed to be equal to the distance between adjacent full or partial restraints. 12. A C (continuous) flange restraint is assumed to be equivalent to a series of L (lateral) flange restraints spaced at increments of 1mm for the length of the continuous restraint. 13. If C (continuous) or I (ignore) flange restraints are repeated without R, S, F, P or L restraints inbetween (eg. CCC, III or CI) then the last C or I restraint is used and the previous repeated ones are discarded. 14. If an intermediate flange restraint is positioned at the beginning or end of a design group then it is ignored in favour of the appropriate end flange restraint. 15. Member offsets are automatically ignored (skipped over) during a steel member design/check provided that they occur at the ends of a design group. They are treated the same as I (ignore) flange restraints. 16. The extra restraint condition in AS1250, SABS0162, BS5950, HK CP2011 and AS3990 that provides partial restraint against lateral rotation (about the cross section minor axis) of the critical flange is not supported. 17. Because it is difficult for SPACE GASS to determine whether a member is a true cantilever or not, AS1250 clause 5.9.4, SABS0162 clause 7.2.3(b),

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SPACE GASS 12 User Manual BS5950 clause 4.3.5.4/4.3.5.5, HK CP2011 clause 8.3.4.3 and AS3990 clause 5.9.4 have not been considered. This may cause the bending effective length for cantilevers to be underestimated and you should therefore check the bending effective length for cantilevers calculated by the AS1250, SABS0162, BS5950, HK CP2011 and AS3990 modules. 18. When calculating kt for AS4100 or NZS3404, if the critical flange switches from top to bottom within the segment, the critical flange thickness is assumed to be the thickness of the flange at the end of the segment. 19. When calculating kl, SPACE GASS assumes conservatively that top flange loads always occur within the segment rather than at the segment end(s). 20. kl is calculated for "downwards" loads regardless of the member orientation and flange positions. A "downwards" load is assumed to act in the direction from the top flange to the bottom flange. If you want kl=1.0 for columns, sloping beams or beams on their side then you should set the load height position to "Shear centre" regardless of the loaded flange or the load direction. 21. The direction of the transverse load acting on a segment is determined by the sign of the difference in shear force between the two segment ends. 22. AS1250, SABS0162, BS5950, HK CP2011 and AS3990 do not give specific rules for calculating kr for all combinations of flange restraints at the ends of the segment. In such cases interpolation has been used to calculate some of the values of kr. 23. Eccentric end connection effects (if not suppressed) are taken into account in different ways depending on the design code being used. In most cases, the eccentric end moments are simply added to the normal design moments for the entire design group. Exceptions are BS5950 which optionally uses the provisions of clauses 4.6.3 (tension) or 4.7.10 (compression) and AS4100 and NZS3404 which use a Kt factor for tension members (if activated). 24. Where applicable (see previous item), moments due to eccentric end connection effects for angles, channels and Tee sections subjected to axial loads are added to the normal design moments only if they don’t cause a net reduction in the final design moment.

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Steel Member Design 25. Eccentric end moments are calculated by multiplying the axial force by the distance from the centroid of the connected plate to the centroid of the cross section. 26. The major axis of a single or double angle section is assumed to be parallel to the short leg(s) of the section. 27. Double angle sections are assumed to have no space between the individual angle sections. 28. The AS1250, SABS0162 and AS3990 modules assume that double angles are connected together at intermediate points sufficient to ensure that half of the design axial compressive force for the combined section does not exceed the compressive capacity of each angle section considered individually using an effective length (for buckling of the sections away from each other) equal to the distance between connection points. 29. The AS1250, SABS0162 and AS3990 modules consider only axial forces and shears for single or double angle sections. Bending moments are not considered. Eccentric end moments are considered where applicable. The AS4100, BS5950, HK CP2011, EUROCODE 3 and NZS3404 modules consider axial forces, shears (along minor axis) and bending moments (about both axes) for single or double angle sections. 30. The AS4100, NZS3404, AISC-ASD, AISC-LRFD, EUROCODE 3, BS5950 and HK CP2011 modules convert double angle sections into the equivalent Tee section and then treat them as a solid Tee shape. The AS4100, NZS3404 and HK CP2011 modules do not support double starred angles. 31. Beam Tees have the major axis parallel to the flange and are therefore assumed to have their web vertical (assuming a zero direction angle and no flipping). 32. Column Tees have the major axis parallel to the web and are assumed to be lying on their side with their flange vertical (assuming a zero direction angle and no flipping). 33. The AS1250, SABS0162 and AS3990 modules do not support column Tee sections.

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SPACE GASS 12 User Manual 34. The AS4100 and NZS3404 modules do not support welded Tee sections unless they are beam Tees with d/t<15 (lightly welded longitudinally) or d/t<14 (heavily welded longitudinally). 35. The AS4100 and NZS3404 modules assume that heavily welded (longitudinally) I and H sections with equal flanges are flame cut. Lightly welded (longitudinally) or unequal flanged I and H sections and all plate web girders are assumed to be welded "as rolled". 36. The AS1250, SABS0162 and AS3990 modules do not support welded box sections. 37. The AS4100 and NZS3404 modules do not support welded circular hollow sections, channels or angles. 38. The AS4100, BS5950, HK CP2011 and NZS3404 modules assume that channel sections have equal flanges. 39. The AS4100, BS5950, HK CP2011 and NZS3404 modules assume that angle sections have uniform plate thicknesses throughout the section. 40. The AS4100 and NZS3404 modules do not support solid sections. 41. The BS5950 and HK CP2011 modules assume that solid sections are class 1. 42. When calculating the area removed from the section due to a bolted end connection, SPACE GASS assumes that the bolts are through the web(s) unless the end connection type is specified as "F", in which case the bolts are assumed to be through the flange(s). 43. The area removed from the section due to a bolted end connection is assumed to apply for a distance of 250mm from each end of the design group. 44. The BS5950 module assumes conservatively that single angle sections are connected with a single fastener for clause 4.7.10. 45. The AS4100 and NZS3404 modules perform a web capacity check in accordance with appendix I. If the check fails, SPACE GASS treats it as a warning rather than a failure condition.

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Steel Member Design 46. Serviceability requirements are not considered automatically. They must be checked manually by direct inspection of displacement diagrams. 47. Torsional effects are not considered. 48. Member end bearing capacity is not considered. 49. For the AS4100 and NZS3404 modules, m is calculated using the formula in clause 5.6.1.1(a)(iii) when the segment is restrained at both ends. If the segment is unrestrained at one end, AS4100 and NZS3404 require the bending moment diagram to be matched to one of the three diagrams shown in table 5.6.2. This is of course very difficult when the bending moment diagram could be any conceivable shape. SPACE GASS therefore adopts a slightly conservative approach and uses m=1.0 when there is no moment at the unrestrained end or m=0.25 when there is a moment at the unrestrained end. 50. The AS4100, BS5950 and NZS3404 modules do not consider shear force in the major axis direction. 51. If any term in the steel member design failure equation becomes negative, it is assumed that the section has failed and a value of 9.99 is used in place of the negative value. 52. The brace, purlin, girt or other member that provides full, partial or lateral restraint to the critical flange of a member must be capable of resisting the force required to provide such restraint. This is not automatically allowed for in the analysis or design. If you wish to take this into account then you should add the restraint forces to your applied loads. The restraint forces are code specific and you should refer to the appropriate clauses for the design code you are using. This effect is particularly important for deep beams where the forces required to restrain the critical flange can be quite high. You should check that your model is capable of withstanding these forces.

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BS5950-1:2000 code specific items Sections considered Incorporates Corrigendum No 1 3 Properties of materials and section properties 3.1 Structural steel 3.1.1 Design Strength 3.1.3 Other properties 3.4 Section properties 3.4.1 Gross cross-section 3.4.2 Net Area 3.4.3 Effective net area 3.4.4 Deductions for bolt holes 3.5 Classification of cross sections 3.5.1 General 3.5.2 Classification 3.5.5 Stress ratios for classification 3.5.6 Effective plastic modulus 3.5.6.1 General 3.5.6.2 I or H sections with equal flanges 3.5.6.3 Rectangular Hollow Sections 3.5.6.4 Circular Hollow Sections 3.6 Slender cross-sections 3.6.1 Effective section properties 3.6.2 Doubly symmetric cross-sections 3.6.2.1 General 3.6.2.2 Effective area 3.6.2.3 Effective modulus when web is fully effective 3.6.2.4 Effective modulus when web is slender 3.6.3 Singly symmetric and unsymmetrical cross-sections 3.6.6 Circular hollow sections 4 Design of structural members 4.1 General 4.1.1 Application 4.1.2 Class of cross section 4.2 Members subject to bending 4.2.1 General 4.2.1.1 General conditions

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Steel Member Design a, c, d, e 4.2.3 Shear Capacity 4.2.5 Moment Capacity 4.2.5.1 General 4.2.5.2 Low Shear 4.2.5.3 High Shear 4.2.5.5 Bolt holes 4.3 Lateral-torsional buckling 4.3.1 General 4.3.4 Destabilizing load 4.3.6 Resistance to lateral-torsional buckling 4.3.6.1 General 4.3.6.2 I, H, channel and Box sections with equal flanges 4.3.6.3 I-sections and box sections with unequal flanges 4.3.6.4 Buckling resistance moment b,c 4.3.6.5 Bending strength pb 4.3.6.6 Equivalent uniform moment factor mLT 4.3.6.7 Equivalent slenderness LT 4.3.6.8 Buckling parameter and torsional index 4.3.6.9 Ratio W 4.3.8 Buckling resistance moment for single angles 4.3.8.1 General 4.3.8.2 Basic method 4.4 Plate Girders 4.4.1 General 4.4.2 Design Strength 4.4.3 Dimensions of webs and flanges 4.4.3.1 General 4.4.3.2 Minimum web thickness for serviceability a 4.4.3.3 Minimum web thickness to avoid compression flange buckling a 4.4.4 Moment Capacity 4.4.4.1 Web not susceptible to shear buckling 4.4.4.2 Web susceptible to shear buckling 4.4.5 Shear buckling resistance 4.4.5.1 General 4.4.5.2 Simplified method 4.6 Tension members 4.6.1 Tension capacity

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SPACE GASS 12 User Manual 4.6.2 Members with eccentric connections 4.6.3 Simple tension members 4.6.3.1 Single angle, channel or T-section members 4.7 Compression members 4.7.2 Slenderness 4.7.4 Compression resistance 4.7.5 Compressive strength 4.7.6 Eccentric connections c 4.7.10 Angle, channel or T-section struts 4.7.10.1 General 4.7.10.2 Single angles a (welded connection) c 4.7.10.4 Single channels b 4.7.10.5 Single T-sections b 4.8 Members with combined moment and axial force 4.8.1 General 4.8.2 Tension members with moments 4.8.2.1 General 4.8.2.2 Simplified method 4.8.2.3 More exact method 4.8.3 Compression members with moments 4.8.3.1 General 4.8.3.2 Cross section capacity 4.8.3.3 Member buckling resistance 4.8.3.3.1 Simplified method 4.8.3.3.2 More exact method for I or H sections with equal flanges 4.8.3.3.3 More exact method for CHS, RHS, or box sections with equal flanges 4.8.3.3.4 Equivalent uniform moment factors 4.9 Members with biaxial moments 6 Connections 6.2 Connections using bolts 6.2.3 Effect of bolt holes on the shear capacity B Lateral-torsional buckling of members subject to bending B.1 Basic case

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Steel Member Design B.2 Buckling resistance B.2.1 Bending strength B.2.2 Perry factor and Robertson constant B.2.3 Uniform I,H and channel sections with equal flanges B.2.4 Uniform I and H sections with unequal flanges B.2.4.1 Equivalent slenderness B.2.4.2 Double curvature bending B.2.6 Box sections (including RHS) B.2.6.1 Equivalent slenderness B.2.6.2 Torsion constant for a box section B.2.6.3 Torsion constant for an RHS B.2.7 Plates and flats B.2.8 T-sections B.2.8.1 Axes B.2.8.2 Equivalent slenderness B.2.8.3 Warping constant B.2.9 Angle sections B.2.9.1 Axes B.2.9.2 Equal angles B.2.9.3 Unequal angles C Compressive strength C.1 Strut formula C.2 Perry factor and Robertson constant H Web buckling resistance H.1 Shear buckling strength H.3 Resistance of a web to combined effects H.3.1 General H.3.2 Reduction factor for shear buckling H.3.3 Sections other than RHS H.3.3.1 Combined shear, moment and axial compression H.3.3.2 Combined shear, moment and axial tension H.3.4 RHS sections H.3.4.1 Combined shear, moment and axial compression H.3.4.2 Combined shear, moment and axial tension I Combined axial compression and bending I.1 Stocky members I.2 Reduced plastic moment capacity I.2.1 I or H section with equal flanges I.4 Single angle members

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SPACE GASS 12 User Manual I.4.1 General I.4.2 Basic method Assumptions 3.1.1 Design strength py obtained from fy in SPACE GASS library. A warning, not a failure is given if py exceeds Us/1.2. py is not adjusted. 3.4.3 The determination of steel grade for calculating the Ke value is based on the SPACE GASS library fy value, falling between the ranges specified in Table 9. 3.4.4 The bolt hole area is based on the values specified in the SPACE GASS Steel Member Design data. 3.5 Solid square and solid circle sections are assumed to be a Class 1. Solid rectangle is assumed to be an I beam with no flange outstands. I and Box shapes use the "Generally" limits in Tables 11 and 12. 3.5.5 Unequal flanges for box sections use r1 eq 3.5.5b divided by 2.0 to allow for the 2 webs. Outstands of box girders are not taken into account for the calculation of r1. 3.6.2.4 When used for webs for channels, webs are assumed to be 40t instead of 120t in accordance with Table 11 and the use of 3.6.3. 4.2.3 Only vertical projection of inclined box girder web considered in shear capacity. 4.2.5.1 A warning, not a failure is given if the 1.2pyZ limit is reached. 4.2.5.2 Alternative for Class 3 sections used. 4.2.5.3 Alternative for Class 3 sections used. Alternative with regards to reference H.3 for Class 3 and 4 sections not considered. 4.2.5.5 Bolt holes assumed to be distributed equally between top and bottom flange for flanges and for webs equally distributed between the tension and compression zone in bending. 4.3.6.7b Channels are loaded through their shear centre. 4.4.4.2c When using H3 and the section has two webs, the web forces are equally shared between the webs - class 4 flanges - only the effective parts of the flanges are used for calculation of flange capacity. 4.4.5 Simplified method used with stiffener spacing equal to infinity. 4.4.5.2 When using H1 to determine qw, sections other than I beams are assumed to be applied in the same way where there are two webs (boxes), the web capacity is for each web. 4.6 Full section properties used except where explicitly specified Zxeff and Sxeff. 4.6.2 If no eccentric moments are added and the section's connected elements cause eccentricity then 4.6.3 used.

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Steel Member Design 4.7.2 The 20% increase in slenderness for alternating restraints has not been allowed for. 4.7.5 Reduced py is used for all welded sections. Table 23 welded angles, channels and Tees are assumed to be rolled but py is reduced as per 4.7.5. Notes 2 and 3 not allowed for. 4.7.6c If no eccentric moments are added and the section's connected elements cause eccentricity then 4.7.10 used. 4.7.10.1 The 20% increase in slenderness for alternating restraints has not been allowed for. 4.7.10.2 If there is a bolt area in one flange only then a single bolt hole is assumed, 80% reduction allowed for. 4.7.10.4 If there is a bolt hole in the web then a single row is assumed. 4.7.10.5 If there is a bolt hole in the flange then a single row is assumed. 4.8.2.3 Only equal flanged I shapes, box shapes and CHS class 1 or 2 use this clause. Other sections use 4.8.2.2. 4.8.2.2 App I.3 not used for asymmetric sections. 4.8.3.2 App I.3 not used for asymmetric sections. 4.8.3.3 App I.1 is used for stocky members. 4.8.3.3.4 mLT is based on the segment length, mx is based on the Group length, my is based on the segment length, myx is based on the group length B.2.4 Channels with unequal flanges treated the same as unequal I beams refer 4.3.6.7b. B.2.9.2 Star angles treated same as single angle but combined properties used. H.3.1 Strut action and moment amplification not allowed for.

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Hong Kong CP2011 code specific items Sections considered 3 Materials 3.1 Structural Steel 3.1.2 Design strength for normal strength steels 3.1.6 Other properties 6 Design Methods and Analysis 6.8 Second-Order P- Elastic Analysis 6.8.2 Method of Analysis items (1) and (2) only 6.8.3 Applications and Limitations 7 Section Classification 7.1 General 7.2 Classification 7.3 Stress Ratios for Classification 7.5 Effective Plastic Modulus 7.5.1 General 7.5.2 I or H Sections with equal flanges 7.5.3 Rectangular hollow sections 7.5.4 Circular hollow sections 7.6 Effective Width method for slender cross sections 7.8 Shift of the centroid of the effective cross section 8 Design of Structural Members 8.1 General 8.2 Restrained Beams 8.2.1 Shear capacity 8.2.2 Moment capacity 8.2.2.1 Low Shear condition 8.2.2.2 High Shear condition 8.3 Lateral-Torsional buckling of Beams 8.3.3 Normal and destabilising loads 8.3.5 Moment resistance to Lateral-torsional buckling 8.3.5.1 Limiting slenderness 8.3.5.2 Buckling resistance moment 8.3.5.3 Equivalent dlenderness for flexural-torsional buckling 8.4 Plate Girders 8.4.1 Design strength

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Steel Member Design 8.4.2 Minimum web thickness for servicability 8.4.3a Minimum web thickness to avoid compression flange buckling 8.4.4 Moment Capacity of restrained girders 8.4.4.1 Web suspectible to shear buckling 8.4.4.2 Web susceptible to shear buckling 8.4.5 Effects of Axial force 8.4.6 Shear buckling resistance 8.5 Buckling resistance moment for a single angle member 8.6 Tension members 8.6.1 Tension Capacity 8.6.2 Members with eccentric connections 8.6.3 Single and double angle, channel and T sections 8.7 Compression Members 8.7.4 Slenderness 8.7.5 Compression resistance 8.7.6 Compressive strength 8.7.7 Eccentric connections 8.8 Tension members under combined axial force and moments 8.9 Compression Members under combined axial force and moments 8.9.1 Cross section capacity 8.9.2 Member buckling resistance 9 Connections 9.3.4.4 Effective area for tension 9.3.4.5 Effective area for shear Appendix 8.1 Appendix 8.2 Appendix 8.3 Assumptions 3.1.2 Class 1 and 1H steels assumed. 6.8.2(3) Frame and member imperfections are not automatically considered in the analysis, however if clause 8.9.2 is used instead of clause 6.8.3 then there is no requirement for member imperfections in the analysis. 1. Mcx and Mcy = Zpy. 7.5.1 I or H sections with unequal flanges Seff = Z as per other sections. 7.6 Same method as BS5950-2000 is adopted to calculate effective section and change in centroid and properties for slender sections but with HK element limits. 8.2 Beam checked whether fully restrained or not. 8.3.5.2 Mb = Mcx from 8.2.2 if Lateral Torsional Buckling need not be checked.

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SPACE GASS 12 User Manual 8.3.5.3 Box sections use this code section. 8.3.5.3 Channels assume that loads pass through shear centre - warning given. 8.4 Webs without intermediate or transverse stiffeners assumed (a = infinity). 8.4.2 Warning given if eq 8.30 not met. 8.4.3 Warning given if eq 8.33 not met. 8.7 No check is done for compressive resistance if clause 6.8.3 is used instead of clause 8.9.2. 8.8 Only eq 8.77 is applied. 8.9.2 If clause 8.9.2 is used instead of clause 6.8.3 then second-order moments are used in equation 8.79, making it slightly conservative. MLT is max moment in segment, Mx is max moment in group and My is max moment in segment.

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Steel Member Design

AISC 360-10 code specific items Sections considered B. DESIGN REQUIREMENTS B3. Design Basis 1. Required Strength 2. Limit States 3. Design for Strength Using Load and Resistance Factor Design (LRFD) 4. Design for Strength Using Allowable Strength Design (ASD) 5. Design for Stability B4. Member Properties 1. Classification of Sections for Local Buckling 1a. Unstiffened Elements 1b. Stiffened Elements 2. Design Wall Thickness for HSS 3. Gross and Net Area Determination 3a. Gross Area 3b. Net Area D. DESIGN OF MEMBERS FOR TENSION D2. Tensile Strength D3. Effective Net Area E. DESIGN OF MEMBERS FOR COMPRESSION E1. General Provisions E2. Effective Length E3. Flexural Buckling of Members without Slender Elements E4. Torsional and Flexural-Torsional Buckling of Members Without Slender Elements E5. Single Angle Compression Members E7. Members with Slender Elements 1. Slender Unstiffened Elements, Qs 2. Slender Stiffened Elements, Qa F. DESIGN OF MEMBERS FOR FLEXURE F1. General Provisions F2. Doubly Symmetric Compact I-Shaped Members and Channels Bent About Their Major Axis 1. Yielding 2. Lateral-Torsional Buckling F3. Doubly Symmetric I-Shaped Members With Compact Webs and Noncompact or Slender Flanges Bent About Their Major Axis 1. Lateral-Torsional Buckling

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SPACE GASS 12 User Manual 2. Compression Flange Local Buckling F4. Other I-Shaped Members With Compact or Noncompact Webs Bent About Their Major Axis 1. Compression Flange Yielding 2. Lateral-Torsional Buckling 3. Compression Flange Local Buckling 4. Tension Flange Yielding F5. Doubly Symmetric and Singly Symmetric I-Shaped Members With Slender Webs Bent About Their Major Axis 1. Compression Flange Yielding 2. Lateral-Torsional Buckling 3. Compression Flange Local Buckling 4. Tension Flange Yielding F6. I-Shaped Members and Channels Bent About Their Minor Axis 1. Yielding 2. Flange Local Buckling F7. Square and Rectangular HSS and Box-Shaped Members 1. Yielding 2. Flange Local Buckling 3. Web Local Buckling F8. Round HSS 1. Yielding 2. Local Buckling F9. Tees and Double Angles Loaded in the Plane of Symmetry 1. Yielding 2. Lateral-Torsional Buckling 3. Flange Local Buckling of Tees 4. Local Buckling of Tee Stems in Flexural Compression F10. Single Angles 1. Yielding 2. Lateral-Torsional Buckling 3. Leg Local Buckling F11. Rectangular Bars and Rounds 1. Yielding 2. Lateral-Torsional Buckling F12. Unsymmetrical Shapes 1. Yielding 2. Lateral-Torsional Buckling 3. Local Buckling F13. Proportions of Beams and Girders 1. Strength Reductions for Members With Holes in the Tension Flange 2. Proportioning Limits for I-Shaped Members

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Steel Member Design G. DESIGN OF MEMBERS FOR SHEAR G1. General Provisions G2. Members With Unstiffened or Stiffened Webs 1. Shear Strength 2. Transverse Stiffeners G3. Tension Field Action 1. Limits on the Use of Tension Field Action 2. Shear Strength With Tension Field Action 3. Transverse Stiffeners G4. Single Angles G5. Rectangular HSS and Box-Shaped Members G6. Round HSS G7. Weak Axis Shear in Doubly Symmetric and Singly Symmetric Shapes H. DESIGN OF MEMBERS FOR COMBINED FORCES AND TORSION H1. Doubly and Singly Symmetric Members Subject to Flexure and Axial Force 1. Doubly and Singly Symmetric Members Subject to Flexure and Compression 2. Doubly and Singly Symmetric Members Subject to Flexure and Tension 3. Doubly Symmetric Rolled Compact Members Subject to Single Axis Flexure and Compression H2. Unsymmetric and Other Members Subject to Flexure and Axial Force H3. Members Subject to Torsion and Combined Torsion, Flexure, Shear and/or Axial force 1. Round and Rectangular HSS Subject to Torsion 2. HSS Subject to Combined Torsion, Shear, Flexure and Axial Force 3. Non-HSS Members Subject to Torsion and Combined Stress H4. Rupture of Flanges With Holes Subject to Tension Limit state equations used D. DESIGN OF MEMBERS FOR TENSION D2-1 Pg 16.1-26 - section,member D2-2 Pg 16.1-26 - section,member E. DESIGN OF MEMBERS FOR COMPRESSION E3-1 Pg 16.1-33 - member E4-1 Pg 16.1-34 - member E7-1 Pg 16.1-40 - member F, DESIGN OF MEMBERS FOR FLEXURE F2-1 Pg 16.1-47 - section, member F2-2 Pg 16.1-47 - member F2-3 Pg 16.1-47 - member F3-1 Pg 16.1-49 - section, member

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SPACE GASS 12 User Manual F3-2 Pg 16.1-49 - section, member F4-1 Pg 16.1-50 - section, member F4-2 Pg 16.1-50 - member F4-3 Pg 16.1-50 - member F4-13 Pg 16.1-52 - section, member F4-14 Pg 16.1-52 - section, member F4-15 Pg 16.1-53 - section, member F5-1 Pg 16.1-54 - section, member F5-2 Pg 16.1-54 - member F5-7 Pg 16.1-55 - section, member F5-10 Pg 16.1-55 - section, member F6-1 Pg 16.1-55 - section, member F6-2 Pg 16.1-56 - section, member F6-4 Pg 16.1-56 - section, member F7-1 Pg 16.1-56 - section, member F7-2 Pg 16.1-57 - section, member F7-3 Pg 16.1-57 - section, member F7-5 Pg 16.1-57 - section, member F8-1 Pg 16.1-57 - section, member F8-2 Pg 16.1-57 - section, member F8-3 Pg 16.1-57 - section, member F9-1 Pg 16.1-58 - section, member F9-4 Pg 16.1-58 - member F9-6 Pg 16.1-59 - section, member F9-7 Pg 16.1-59 - section, member F9-8 Pg 16.1-59 - section, member F10-1 Pg 16.1-60 - section, member F10-2 Pg 16.1-60 - member F10-3 Pg 16.1-61 - member F10-7 Pg 16.1-62 - section, member F10-8 Pg 16.1-62 - section, member F11-1 Pg 16.1-63 - section, member F11-2 Pg 16.1-63 - member F11-3 Pg 16.1-63 - member F12-1 Pg 16.1-63 - section, member F13-1 Pg 16.1-64 - section, member G. DESIGN OF MEMBERS FOR SHEAR G2-1 Pg 16.1-67 - section, member, shear G6-1 Pg 16.1-72 - section, member, shear H. DESIGN OF MEMBERS FOR COMBINED FORCES AND TORSION H1-1a Pg 16.1-73 - member H1-1b Pg 16.1-73 - member

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Steel Member Design H1-2 H2-1 H3-1 H3-6 H3-8 H4-1

Pg 16.1-75 - member Pg 16.1-76 - section, member Pg 16.1-77 - section, member Pg 16.1-78 - section, member Pg 16.1-79 - section, member Pg 16.1-79 - section

Assumptions GENERAL RHS and SHS root radius is inside radius. Flange bolt holes equally divided between flanges. Web bolt holes equally divided between webs where applicable. If the design calculates a high Ultimate Load Factor then a default failure equation (Yield about xx axis) will be returned. Warning - If a value has exceeded a limit related to a warning, the value is NOT adjusted to be within that limit, its actual value is used in the calculation. Section B4.2 Design Wall Thickness for HSS The wall thickness from the section properties is always multiplied by 0.93 factor. Section B4.3b. Net Area 1/16" or 2 mm allowance for hole diameter already assumed to be allowed for in the design data input. No allowance for chain holes made. Chapter D Design of Members for Tension Pin connected members not checked. Block shear strength not checked. Eyebars not checked. Section D3. Effective Net Area A number of factors are unknown ie the length of the connection, number of bolts in line and the type of the weld used. The user has the choice to leave U as 1.0 via the U flag or turn it on and use the conservative approach as detailed in the Commentary Page 16.1-250 where the net area of the connected elements are used as Ae. A U value is returned to indicate the reduction from the net area ie U = Ae/An. Shapes 0-3 use a worst case assumption of U = 0.75. Section E5 Single Angle Compression members Section E5.(a) used - group length used as they are individual members or web members. Section F Outstands on box girders treated as tee flanges. Non double symmetric box girders are not supported by F7, each flange and web is still checked individually.

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SPACE GASS 12 User Manual No allowance made for loads placed above or below the centroid. No allowance for cantilevers in calculation of Cb. Section F10. Single Angles Bending about principal axis only. Section F11.1 Yielding of solid bars, warning issued if slenderness limit exceeded, capacities still calculated. Section F13.2 Proportions limits for I shaped members Warning given if limits exceeded, calculations still done even though limits have been exceeded. Section G No reduction in shear areas for bolt holes. No web transverse stiffeners assumed. No shear tension field action is considered (Sect G3). Solid circle shear done same as CHS with wall thickness same as radius. Section G4 Single Angles Star shapes have double shear capacity of equivalent single angle. Section G5 Rectangular HSS and Box shaped members Box sections with different thickness flanges and possibly outstands, the element that produces the worst Cv value is used as the controlling cv and the sum of all of the contributing shear elements is used for Aw. If there is a flange outstand on the box girder these are treated like a T stem kv = 1.2. Section G7 weak axis shear If any torsion then equation H3-8 used. Section H1.3 Applied if section is rolled compact in flexure about major axis (axial class ignored).

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Eurocode EN 1993-1-1:2005 code specific items Sections considered 1. General 1.1.2(1) Scope of Part 1.1 of Eurocode 3 1.7 Conventions for member axes 3. Materials 3.2.2(1) Ductility requirements fu/fy 3.2.6(1) Design values of material coefficients 5. Structural analysis 5.5 Classification of cross sections 5.5.1 Basis 5.5.2 Classification (1),(2),(3),(4),(5),(6),(7),(8),(10) 6. Ultimate limit states 6.1 General (1),(3),(4) 6.2.2 Section properties 6.2.2.1 Gross cross-section 6.2.2.2 Net area (1),(2),(3) 6.2.2.5 Effective cross-section properties for Class 4 cross-sections (1),(2),(3),(4) 6.2.3 Tension (1),(2),(3),(5) 6.2.4 Compression (1),(2),(3),(4) 6.2.5 Bending moment (1),(2),(3),(4),(5),(6) 6.2.6 Shear (1),(2),(3),(4),(5),(6),(7) 6.2.8 Bending and shear (1),(2),(3),(5) 6.2.9 Bending and axial force 6.2.9.1 Class 1 and 2 cross-sections (1),(2),(3),(4),(5),(6) 6.2.9.2 Class 3 cross-sections 6.2.9.3 Class 4 cross-sections (2) 6.2.10 Bending, shear and axial force

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SPACE GASS 12 User Manual (1),(2),(3) 6.3 Buckling resistance of members 6.3.1 Uniform members in compression 6.3.1.1 Buckling resistance (1),(2),(3),(4) 6.3.1.2 Buckling curves (1),(2),(4) 6.3.1.3 Slenderness for flexural buckling (1),(2) 6.3.1.4 Slenderness for torsional and torsional-flexural buckling (1),(2),(3) 6.3.2 Uniform members in bending 6.3.2.1 Buckling resistance (1),(2),(4) 6.3.2.2 Lateral torsional buckling curves – General case (1),(2),(4) 6.3.2.3 Lateral torsional buckling for rolled sections or equivalent welded sections (1),(2) 6.3.2.4 Simplified assessment methods for beams with restraints in buildings (1),(2),(3) 6.3.3 Uniform members in bending and axial compression (2),(3),(4),(5) Annex A – Method 1: interaction factors kij for interaction formula in 6.3.3(4) Annex B – Method 2: interaction factors kij for interaction formula in 6.3.3(4) UK National Annex to Eurocode EN 1993-1-1:2005 NA.2.15 Partial safety factors for buildings NA.2.16 Imperfection factors for lateral torsional buckling NA.2.17 Lateral torsional buckling for rolled sections or equivalent welded sections NA.2.18 Modification factor, f NA.2.19 The slenderness limit lambdac0 NA.2.20 Modification factor, kfl NA.2.21 Interactions factor kyy,kyz,kzy and kzz NA3.1 BS EN 1993-1-1:2005, Annex A NA3.2 BS EN 1993-1-1:2005, Annex B Eurocode EN 1993-1-1:1992 Annex F: Lateral torsional buckling

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Eurocode EN 1993-1-5:2006 Plated structural elements 4 Plate buckling effects due to direct stresses at the ultimate limit state 4.1 General 4.2 Resistance to direct stresses 4.3 Effective cross section (3),(4) 4.4 Plate elements without longitudinal stiffeners (1),(2) 5 Resistance to shear 5.1 Basis (1),(2) 5.2 Design resistance (1) 5.3 Contribution from the web (1),(3)a 5.5 Verification 7 Interaction 7.1 Interaction between shear force, bending moment and axial force (1),(2),(4) UK National Annex to Eurocode EN 1993-1-5:2005 NA.2.4 Basis Eurocode EN 1993-1-8:2005 Design of joints 3.10.3 Angles connected by one leg and other unsymmetrically connected members in tension (1),(2) 4.13 Angles connected by one leg (1),(2),(3) Limit state equations used 6.2.3 Tension (6.5) page 49 – section 6.2.4 Compression (6.9) page 49 – section 6.2.5 Bending moment (6.12) page 50 – section 6.2.6 Shear (6.17) page 50 – section, shear (6.19) page 51 – section, shear 6.2.9 Bending and axial force

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SPACE GASS 12 User Manual (6.31) page 54 – section (6.41) page 55 – section (6.44) page 56 – section 6.3.1.1 Compression buckling resistance (6.46) page 56 - member 6.3.2.1 Bending buckling resistance (6.54) page 60 - member 6.3.3 Uniform members in bending and axial compression (6.61) page 65 – member (6.62) page 65 – member EN 1993-1-5:2006 5 Resistance to shear (5.10) page 25 – section, shear EN 1993-1-5:2006 7.1 Interaction between shear force, bending moment and axial force (7.1) page 28 – section, shear Assumptions Torsion is not considered. No block or shear lag effects considered. Hybrid girders not considered. Webs are unstiffened. Flange bolt holes equally divided between flanges. Web bolt holes equally divided between webs where applicable. If the design calculates a high Ultimate Load Factor then a default failure equation (Yield about xx axis) will be returned. 3.2.6 G = 80769.231. 6.2.3(5) Tension – Channels connected only through the web and tees connected only through the flange, the effective area is taken as the effective area of the connected element plus half the area of the outstanding elements. 6.2.6(2) check is done even if there is torsion (torsion is not considered). 6.2.6(5) smallest flange area used. 6.2.9.1(4) I, channel and box shapes considered. 6.2.9.2(1) equation (6.44) used. 6.3.2.2(2) Mcr is calculated using EN 1993-1-1:1992 Annex F, including channel and unequal angles. Table A.2 Cmi0 based on member group. Table B3 the highest Cm value calculated for uniform or concentrated load is used. Table B.3 Cmy based on member group. Table B.3 Cmz based on member segment. Table B.3 CmLT based on member segment. EN 1993-1-5:2006 5.2 Design resistance to shear – No contribution from flanges allowed.

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Steel Member Design EN 1993-1-8:2005 3.10.3 – 1 bolt, 1 row assumed.

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AS/NZS 4600:2005 code specific items Sections considered AS/NZS 4600:2005 Cold-formed steel structures (incorporating amendment 1) SECTION 1 SCOPE AND GENERAL 1.1 SCOPE (thickness) 1.3 DEFINITIONS 1.3.5 Bend 1.5 MATERIALS 1.5.1.4 Ductility (fu/fy ratio) 1.6 DESIGN REQUIREMENTS 1.6.3(a) Design capacity Table 1.6 (b),(c),(d),(e),(f) SECTION 2 ELEMENTS 2.1 SECTION PROPERTIES 2.1.1 General 2.1.2 Design procedures 2.1.2.1 Full section properties 2.1.2.2 Effective section properties (b) local instabilities 2.1.3 Dimensional limits 2.1.3.1 Maximum flat-width-to-thickness ratios (a)(i),(b),(c) 2.1.3.4 Maximum web depth-to-thickness ratio (a) unreinforced webs 2.2 EFFECTIVE WIDTHS OF STIFFENED ELEMENTS 2.2.1 Uniformly compressed stiffened elements 2.2.1.1 General 2.2.1.2 Effective width for capacity calculations (a),(c),(i),(ii) 2.2.1.3 Effective width for deflection calculations (a) Procedure I 2.2.3 Stiffened elements with stress gradient 2.2.3.1 General 2.2.3.2 Effective width for capacity calculations 2.2.3.3 Effective width for deflection calculations 2.3 EFFECTIVE WIDTHS OF UNSTIFFENED ELEMENTS

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Steel Member Design 2.3.1 Uniformly compressed unstiffened elements 2.3.1.1 General 2.3.1.2 Effective width for capacity calculations 2.3.1.3 Effective width for deflection calculations 2.3.2 Unstiffened elements and edge stiffeners with stress gradient 2.3.2.1 General 2.3.2.2 Effective width for capacity calculations 2.3.2.3 Effective width for deflection calculations 2.4 EFFECTIVE WIDTH OF UNIFORMLY COMPRESSED ELEMENTS WITH AN EDGE STIFFENER 2.4.1 General 2.4.2 Effective width for capacity calculations 2.4.3 Effective width for deflection calculations SECTION 3 MEMBERS 3.1 GENERAL 3.2 MEMBERS SUBJECT TO AXIAL TENSION 3.2.1 Design for axial tension 3.2.2 Nominal section capacity 3.2.3 Distribution of forces 3.2.3.1 End connections providing uniform force distribution 3.2.3.2 End connections providing non-uniform force distribution 3.3 MEMBERS SUBJECT TO BENDING 3.3.1 Bending moment 3.3.2 Nominal section moment capacity 3.3.2.1 General 3.3.2.2 Based on initiation of yielding 3.3.3 Nominal member moment capacity 3.3.3.1 General 3.3.3.2 Members subject to lateral buckling 3.3.3.2.1 Open section members 3.3.3.2.2 Closed box members 3.3.3.3 Members subject to distortional buckling 3.3.3.4 Beams having one flange through-fastened to sheeting 3.3.4 Shear 3.3.4.1 Shear capacity of webs without holes 3.4 CONCENTRICALLY LOADED COMPRESSION MEMBERS 3.4.1 General 3.4.2 Sections not subject to torsional or flexural-torsional buckling equation 3.4.2(1) only 3.4.3 Doubly- or singly-symmetric sections subject to torsional or flexuraltorsional buckling

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SPACE GASS 12 User Manual 3.4.4 Point-symmetric sections 3.4.5 Non-symmetric sections 3.4.6 Singly-symetric sections subject to distortional buckling 3.4.7 Columns with one flange through-fastened to sheeting 3.6 CYLINDRICAL TUBULAR MEMBERS 3.6.1 General 3.6.2 Bending 3.6.3 Compression 3.6.4 Combined bending and compression APPENDIX D DISTORTIONAL BUCKLING STRESSES OF GENERAL CHANNELS, LIPPED CHANNELS AND Z-SECTIONS IN COMPRESSION AND BENDING D2 SIMPLE LIPPED CHANNELS IN COMPRESSION D3 SIMPLE LIPPED CHANNELS OR Z-SECTIONS IN BENDING ABOUT THE AXIS PERPENDICULAR TO THE WEB Assumptions fy and fu are read directly from section properties. No reductions or increases in fy from Clause 1.5.1.2 - Strength increase resulting from cold forming, or Clause 1.5.1.4(b) - Ductility. Shapes with intermediate stiffeners are not supported. Unlipped (plain) Cee flanges are assumed to be an unstiffened element and the web a stiffened element. Webs of top hats that have edge stiffened bottom flanges are assumed to be a stiffened element (ie. flanges are assumed to provide sufficient edge support to the web to have the web classified as stiffened). A ratio of effective section I to gross section I is included in the design report to provide a deflection factor approximating the increase in gross section deflections at the reported design load forces and moments. The SPACE GASS analysis deflections are based on gross sections. Clause 1.3.39 - a single lateral restraint 'L' not combined with any other flange restraint is not recognised as an effective restraint for a segment as they do not meet the requirements of a partially retrained cross section for a segment. Clause 1.3.39 - a continuous lateral restraint 'C' is recognised as a restraint and assumed to meet the requirements of a partially restrained cross section for a segment. Clause 2.1.1 - full section properties and yield strengths read directly from section properties. Clause 2.1.2.1 - actual shape including bends is used to calculate effective section properties.

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Steel Member Design Clause 2.1.3.1 - failure if elements exceed prescribed ratios, warning given if elements exceed clause note's ratios. Clause 2.1.3.3 - shear lag effects not considered. A warning given if group length < 30 * flange width. Clause 2.2.1.3 - procedure I used, Procedure II not used. Clause 3.2.3.1 - it is assumed (a) and (b) are satisfied for concentric end connections. Clause 3.2.3.2 - for channels connected by flanges only, it is assumed b(i) and b(ii) are satisfied. Clause 3.3.3.2.1(b) - Iyc for zeds taken as geometric axis Iy/2. Clause 3.3.2.3 - section moment capacity based on inelastic reserve capacity NOT considered. Clause 3.3.3 - unequal angles, equation 3.3.3.2(13) used for bending in x and y axis. Clause 3.3.3 - Mo is NOT calculated using a rational flexural-torsional buckling analysis. Clause 3.3.3.3 - only lipped cee, lipped cee back to back and zed sections considered for distortional buckling . Clause 3.3.3.2.1(a) - alternative for Z-sections restrained by sheeting against lateral movement NOT considered. Clause 3.3.3.4 - only (i),(ii),(iii),(iv),(v),(vii)(vii based on group length) requirements are checked, assumed other requirements checked by user. Clause 3.3.4.1 - no shear buckling check on CHS sections. Clause 3.3.4 - for top hat sections, shear in x axis carried by top flange and horizontal component of web, shear in y axis carried by vertical component of the web. Clause 3.4.1 - holes have not been allowed for in the calculation of Ae for Nc. Clause 3.4.2 - grade 550 shapes less than 0.9mm thickness not supported. Clause 3.4.2 - clause notes not applied. User to specify effective lengths in steel member design group properties. Clause 3.4.3 - alternative equation 3.4.3(2) not considered. Clause 3.4.3 - equal angles, if no area reduction due to fy, foc based on maximum compressive length and smallest radius of gyration in either axis. Clause 3.4.6 - only lipped single or back to back cee considered for axial compression distortional buckling. Clause 3.4.6 - Fod calculated using Appendix D2. Clause 3.4.7 - s = 0.5 (fastener in centre of flange), smallest flange width used for zed sections. Clause 3.4.7 - only (i),(ii),(iii),(iv),(v),(vi),(ix),(x based on group length) requirements are checked, assumed other requirements checked by user. Clause 3.5 - equations 3.5.1(2) and 3.5.2(2) are included in section checks. Msx and Msy are used in equation 3.5.1(2)for the section check.

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SPACE GASS 12 User Manual Clause 3.5.1 - equations 3.5.1(1) and 3.5.1(2) are included in member checks, equation 3.5.1(3) is used if N*/phicNc <= 0.15. Clause 3.5.1 - actual group length used for L in the L/1000 centroid shift for angles. Clause 3.5.2 - equation 3.5.2(1) is included in member checks only. Clause 3.5.2 - equation 3.5.2(1) the axial tension term is conservatively ignored (N* is always zero) if axial tension exists. Clause 3.6.3 - axial compression section capacity for CHS is based on gross area. Appendix D - for zeds, the widest flange is used determining flange and lip properties. Appendix D - flange and lip properties represented as square corners and centrelines. Appendix D3 - no reduction in lambda for any bracing interval.

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Steel member design/check errors SPACE GASS performs numerous checks for illegal and inconsistent data. Many of these checks are done in the steel member design data input modules and any errors detected there must be corrected immediately. However, some errors such as faulty member groupings cannot be detected until the design/check phase. All of the errors in the following list cause SPACE GASS to abort the design or check of the current design group and move on to the next group. If an error occurs during a design or an uninterrupted check, the program continues without alerting you and puts the error message in the output report. Alternatively, if an error occurs during an interrupted check, the program pauses to display the message and, if it is a section related error, gives you the opportunity to manually select other sections to be checked. Warnings also appear in the output report but they do not cause SPACE GASS to abort the design or check of the current design group. This group contains a non-existent or repeated member One of the analysis members nominated in the design group does not exist or has been repeated. Members in this group are not of the same section type All analysis members in the design group must have the same section property number. This group does not have a contiguous run of members All of the analysis members nominated in the design group must be connected together end-to-end in the frame analysis model. They must also be listed in the design group in the order that they are connected (from either end). A tens/comp-only member in this group is disabled One of the analysis members in the design group is a tension-only or compressiononly member which has been disabled during the analysis, thus leaving a gap in the group. A member in this group has buckled One of the analysis members in the design group has buckled during the analysis, thus leaving a gap in the group.

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SPACE GASS 12 User Manual Stations per member limit has been exceeded The stations per analysis member limit has been exceeded or the stations per design group limit has been exceeded. There is a limit of 500 stations per analysis member which must be enough for the number of intermediate member stations that you specify, plus the extra stations at the ends, at concentrated member loads and at flange restraint points. The solution is to either add a node at midspan of the analysis member which has too many stations or decrease the number of stations that you specify at the start of the member design/check phase. A flange restraint is off the end of the member group One or more flange restraints have been specified beyond the end of the design group. Inappropriate group code or shape not supported The section data from the library has an invalid group code or shape code (see also Section libraries). Starred angles cannot be made up from unequal angles Starred angles can only be made from equal angle sections. Starred angles are not supported for this design code This is a restriction in the AS4100, BS5950 and NZS3404 modules. This section shape not supported for this design code The selected steel member design module does not support the shape of the section currently being designed or checked. Inappropriate end connection code for this section An end connection code which is inappropriate for the section being considered has been input. For example, an I or H section can have end codes of "Flange(s)", "Web" or "Centroid", or a single angle section can have end codes of "Short" or "Long". Note that single angle sections cannot have end connection codes of "Centroid". If eccentric effects for angles are to be ignored, they must be disabled at the start of the member design/check phase. Invalid fabrication code for this section The section data from the library has an invalid fabrication code (see also Section libraries) or a rolled section has a fabrication code which shows it to be welded. Inappropriate section dimensions for this design code

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Steel Member Design A code specific constraint on section dimensions has not been met. For example, the BS5950 module requires channels to have equal flanges. For dimension constraints, see also Steel member design/check assumptions. No suitable section found The steel member design module has found that all sections from the library which comply with the library scan code are inadequate. WARNING: You have suppressed eccentric end connection effects If eccentric end effects for members which are not connected concentrically have been disabled at the start of the design/check phase then this warning appears in the output report. WARNING: Not all load cases considered have been analysed non-linearly For AS4100 and NZS3404, a warning appears in the output report if any member design/check load cases have only been analysed linearly. WARNING: Web is inadequate for combined actions (App I) (Lf=#.##) For AS4100 and NZS3404, a warning appears in the output report if the web is inadequate. It suggests that web stiffeners may be required. The web failure load factor is also given. WARNING: Angle calculations do not consider bending moments. Do a manual check For AS1250, SABS0162 and AS3990, the calculations for angle sections do not consider bending moments (apart from eccentric end moments). They should be checked manually.

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Steel Connection Design Steel connection design The SPACE GASS steel connection design module lets you design or check any of the connections in a structural model.

Some key features of the module are as follows:  Fully integrated into SPACE GASS.  Design actions obtained directly from the analysis results.  Multiple load cases considered simultaneously.  Design and checking modes available.

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SPACE GASS 12 User Manual     

Fully rendered 3D images of each connection generated. Annotated elevations detailing all the connection components. Connections able to be exported to other programs. Fully compliant with the 2007 - 2014 ASI Steel Connection Design Guides. All bolts, welds, plates, cleats, stiffeners and doubler plates designed/checked. A video showing the steel connection design module in action can be viewed at www.spacegass.com/connect. Note that if you haven't purchased the steel connection design module, you can still run it in a free trial mode that limits you to using minimum design actions, and prevents you from exporting or saving the job. All other features are fully activated. The connection design module is currently limited to open sections, however connections for closed (tubular) sections are currently under development and are expected to become available in the second half of 2014. Refer to "Creating and editing connections", "The connection manager", "Design considerations", "Connection reports" and "Connection preferences" for full details of the connection design module.

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Creating and editing connections In order to define a connection, it is simply a matter of selecting the members to be connected, clicking the right mouse button and then selecting "Steel Connection Design" from the menu that appears. Note that most connections require two members to be selected, however for a base plate or single member stiff seat connection only one member needs to be selected.

You must then select the type of connection you want from the following table. Connections that are invalid for the number of members you selected will be disabled in the table.

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Alternatively, if you wish to make it the same as a connection that has already been created, you can click the "Copy from Existing Connection" button and then select from a list of the existing connections.

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Note that if your model already contains connections, you can see which ones are attached to a particular member by selecting that member, clicking the right mouse button, choosing "Steel Connection Design" from the menu and, if the selected member already has connections they will be displayed in the following table. You can then click "Add New Connection" to create a new connection for that member or edit one of its existing ones.

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Regardless of which of the above methods you used, the connection is then designed (or checked if you have copied from an existing connection) and the results are presented in the connection editor shown below.

From there, you can examine the connection, click the Ok button to save and exit if you happy with it, or make changes to customize it to your exact requirements. Connection viewer The connection viewer in the right-hand side of the editor gives you a realistic 3D rendered view of the connection. You can zoom, pan and rotate the image using the mouse in the normal way.

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Or you can click the buttons at the top of the connection viewer to do a "Zoom fit", display annotated 2D elevations or switch back to the 3D rendered image.

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Input/edit fields In order to edit the connection, you can change any of the data fields in the lefthand side panel. Some of the key input fields are as follows:

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Connection number This is the unique identification number of each connection. By default it is set to the node number at the connection, however if that number is already taken by another connection then it uses the next available number. You can manually set it to comply with whatever numbering scheme you prefer. Design code Currently only AS4100 is available. Title You can specify an optional title that helps you to identify each connection. If you leave it blank then the connection is referred to by its number and connection type. Supporting and supported member These are the members that are connected to each other. When you first create the connection, SPACE GASS automatically determines which member is the supporting member and which one is supported, however if you wish to swap them you can do so in this form. You can also set the strength for each of the members. Connection type If you wish to change the connection type to one of a similar category then you can do so with this field. For example, you could change a bolted end plate to a welded moment connection or a web side plate to a flexible end plate, however you couldn't change a bolted end plate to a web side plate because they are in different categories. If you wish to change to a connection of a different category then you must click the "Change Connection Type" button on the right side of the editor and then re-select from the table of connection types.

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Steel Connection Design Stiffen web/flange if necessary Ticking these options means that web or flange stiffeners will be included in a design only if required. If you untick these options and stiffeners are required then the connection will fail. Stiffen end plate If you tick this option then the end plate will always be stiffened and this may result in a thinner end plate than would otherwise be required. Load cases If you want to consider all load cases then this field should be left blank, otherwise you should type in your desired list of load cases (separated by commas or dashes). Alternatively, you can click the "..." button to the right of the input field and then select the load cases you want from the list that appears as shown below.

Minimum design actions In order to ensure that each connection is well proportioned and robust, especially when the analysis design actions are quite low, the code nominates minimum design actions that should be complied with. Normally you would leave this option ticked, however you can turn it off if required. Note that if you haven't purchased the steel connection design module, you can still run it in a free trial mode that limits you to using minimum design actions. When

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SPACE GASS 12 User Manual running in this mode, any load cases you type into the "Load cases" field are ignored and you can't turn off the "Minimum design actions" option. Haunches, plates, welds, bolts, stiffeners and cleats The remainder of the input fields involving haunches, plates, bolts, stiffeners and cleats are connection dependent. You can change any of them to configure a library button give you connection to exactly what you want. Any fields with a access to the relevant library for the type of data being input. Designing and checking When you first create a connection, it is automatically designed and the results are presented in the connection editor. You can either accept it in that state or you can proceed to make changes and then have it checked.

If you change one of the input fields that could be overwritten by a design, the connection becomes locked. This is a safety feature that guards against you inadvertently clicking the "Design" button and losing your changes. If you really want to design the connection after making changes that lock it then you must first click the padlock button to unlock it.

Note that some input fields do not cause the connection to be locked, as they are input fields only and are not overwritten when you perform a design. Examples of these are bolt strength, bolting procedure, weld strength, etc. Locking a connection If you wish to prevent any further changes to a connection that isn't already locked, you can lock it by clicking the padlock button. This will stop any of the components of the connection from being changed if a batch design is performed via the connection manager.

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Steel Connection Design Auto check If the "Auto check" option is ticked then a check is automatically done as soon as you make a change to any component of your connection. If it is unticked then no checking is done until you click the "Check" button. Connection status The status line at the bottom of the editor indicates whether the connection has passed, failed or passed with a warning. It includes the critical load case, the utilization ratio and a brief explanation of the failure mode or warning message. A green line indicates it has passed, red indicates failure and yellow is for a pass with a warning message. All of these colors can be changed via the "Preferences" button.

Key diagrams The symbols used in the connection input fields match the ASI design guides, however some of the commonly used ones are also shown in key diagrams that you can view by clicking the "Key Diagram" button.

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Hiding components If you wish to examine components of the connection that may be difficult to see or partially obscured, you can turn on or off the members, plates, bolts or welds using the buttons shown below. They are all on by default.

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Reset If you wish to undo all the changes made to a connection (except for its connection number and title), you can click the "Reset" button. This will put it back to its default state, the same as if you deleted the connection and then re-created it.

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Steel Connection Design Reports A single report (including a graphical representation of the connection) for the connection currently in the editor can be obtained by clicking the "Report" button. Alternatively, you can generate text reports for multiple connections via the report panel of the connection manager or via the normal SPACE GASS report generator in the non-renderer window. Refer to "Connection reports" for more information. Exporting You can export the current connection to a CAD system via the "DXF" or "DWG" buttons. It can then be imported into AutoCAD or any other program that supports those formats. Preferences The "Preferences" button lets you change various connection parameters and colors. For more information refer to "Connection preferences". Infotips Once you have created some connections, you can hover over a node or member in your model to see which connections are attached to it.

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The connection manager The connection manager is at the heart of the steel connection design module. It presents all of your connections in a table and lets you scroll through them, viewing each one as you go. You can also delete connections, edit them, generate reports or perform a batch design/check on multiple connections. You can get to the connection manager by clicking the toolbar of the renderer.

button in the top

Connection table You can click on any connection in the table to see it in the connection manager viewer or you can scroll through them by using the up and down arrow keys on your keyboard. You can double-click any connection in the table to open it in the connection editor or alternatively you could use the "Edit Connection" button at the bottom of the table.

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The colored blocks in the first column signify whether the connection has passed (green), failed (red), passed with a warning (yellow) or not yet design/checked (white). By hovering over the colored block for a particular connection you can obtain its critical load case, utilization ratio, failure mode (if failed) or warning message (if there is one). Note that any of the colors can be changed via the "Preferences" button. The second column indicates whether the connection has been design ("D") or checked ("C"). The remaining columns list the members involved in each connection, the connection type and its title. Connections can be added or deleted by using the "Add Connection" or "Delete Connection" buttons at the bottom. It is recommended that new connections are added by using the procedure explained in "Creating and editing connections" rather than via the "Add Connection" button here.

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SPACE GASS 12 User Manual Batch design/check You can use this section of the manager to design or check all of your connections or just some of them. This will be required from time to time if your model has been changed and/or re-analysed.

Connections If you want to design/check all connections then this field should be left blank, otherwise you should type in your desired list of connections (separated by commas or dashes). Alternatively, you can click the "..." button to the right of the input field and then select the connections you want from the list that appears as shown below.

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Load cases If you want to consider all load cases then this field should be left blank, otherwise you should type in your desired list of load cases (separated by commas or dashes). Alternatively, you can click the "..." button to the right of the input field and then select the load cases you want from the list that appears as shown below.

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SPACE GASS 12 User Manual Check Tick this option if you want the locked connections (usually marked with a "C" in the second column) to be checked. These are the connections that have been locked manually via the padlock button or locked automatically due to changes made to them in the connection editor. They will simply be checked for adequacy and none of their components or design parameters will be changed during the check. Note that if the "Design" option is unticked then the locked and unlocked connections will be checked. Design Tick this option if you want the unlocked connections (usually marked with a "D") in the second column to be designed. During the design some of their components may be changed if the model or the design actions have changed since the last design. Include locked connections If you want to override any locked connections and design them anyway then you should tick this option. During the batch design/check, all the connections encountered that are locked will be designed instead of being checked, however at the end they will be re-locked. Skip connections already designed or checked If you have a large number of connections in your model, you may be able to save some design/check time by ticking this option to skip the ones that have already been designed or checked. For most jobs this time saving will be minimal and so you should generally leave it unticked. Reports Text reports for multiple connections can be generated by filling out the following form and then clicking the "Generate Report" button. Alternatively, you can click the "Report" button in the connection editor to obtain a report (including a graphical representation of the connection) for the connection currently in the editor. You can also obtain text reports via the normal SPACE GASS report generator in the non-renderer window. Refer to "Connection reports" for more information.

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Exporting and importing connections Connection data can be exported to various file formats including MS-Excel and MS-Access. You can also import from MS-Excel and MS-Access. To export from the connection table you should select all of the connections to be exported, click the right mouse button, select "Export" and then choose the desired export format. To import, just click the right mouse button and choose "Import". Note that the data being exported/imported is limited to the connection number, the associated member numbers, the connection type and its title. None of the detailed connection data is included. This means that any changes you have made to a connection will not be included in the exported file and will be lost if you then reimport the file. For designed connections however, once you import the data and re-design the connections, all of the detailed connection data will be re-instated.

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Preferences The "Preferences" button lets you change various connection parameters and colors. For more information refer to "Connection preferences".

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Design considerations Design procedure The design procedure varies for each connection type, however the general procedure is as follows: 1. An initial plate size is chosen from the plate library, starting with the smallest size. 2. An initial bolt size and bolt count is chosen from the bolt library, starting with the smallest size. The bolt count depends on the bolt size, the plate size and the connection type. 3. An initial weld is chosen from the weld library, starting with the smallest size. 4. A number of checks are performed to determine the adequacy of each component and the overall adequacy of the connection. If everything passes then the design stops. If not, it continues as follows. 5. If any weld checks fail, the weld size is incremented (or is changed from a fillet to a butt weld) and the procedure returns to step 4. If the maximum weld size has been reached without a solution, the procedure continues as follows. 6. If any bolt checks fail, the bolt size is incremented and the procedure returns to step 3. If the maximum bolt size has been reached without a solution, the procedure continues as follows. 7. If any plate checks fail, the plate size is incremented and the procedure returns to step 2. If the maximum plate size has been reached without a solution then the connection fails. Note that the actual procedure is somewhat more complicated than described above due to the differing nature of the interaction between the plates, bolts and welds for each connection type. Design actions Some of the design actions that occur at a connection are not relevant for every connection type. The design actions considered for each connection type are listed in the following table.

Fx (Axial force)

Fy (Major Fz (Minor Mx axis axis (Torsion) shear) shear)

Mz My (Major (Minor axis axis moment) moment)

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Bolted end plate Welded moment Bolted apex Fully bolted splice Fully welded splice Bolted / welded splice Web side plate Flexible end plate Bolted angle cleat Bolted angle seat Welded angle seat Bearing pad Stiff seat Pinned baseplate

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Zero member strength During a connection design/check, the module also checks that the member has sufficient section capacity to transfer the design actions to the connection. If you get an error message stating that "The supporting or supported member has zero strength...", it means that the member's Fy or Fyw value is zero. To fix this, you should open the shape builder for the member in question, click the "Design Properties" button and then ensure that the Fy and Fyw values are non-zero. Note that if the Fy and Fyw are already non-zero, it means that the shape builder has obtained them and put them into the fields for you. You should save the new properties, re-analyse the model and then try the connection design again.

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Connection reports Text reports can be generated via the following form in the connection manager, via the normal SPACE GASS report generator in the non-renderer window or via the "Report" button in the connection editor. After specifying which connections are to be included in the report and ticking the other desired options in the above form, you should click the "Generate Report" button.

The following report is for a single connection that was generated from within the connection editor.

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Connection preferences You can change the defaults for various connection parameters such as dimensions, size ranges, strength grades, colors and other options. Note that not all parameters are used in all connections. For example, the default bolt gauge is overridden by other requirements in the bolted end plate connection and others. The bolt size, weld size and plate thickness ranges limit the size of the bolts, welds and plates in a design and allow you to exclude sizes that are unavailable or not desired. Most colors can also be changed and you can see the immediate effect of your changes in the sample image on the right and in the sample pass/warning/fail status bars at the bottom.

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Concrete Column Design Concrete column design This section describes in detail the general use of the concrete column design module. It also includes explanations of all of the fields you need to complete to perform a concrete column design or check. Capabilities of the concrete column design module include:  

              

Design and checking modes. Rectangular, circular, trapezoidal, tee, cruciform and non-standard shapes. Multiple rectangular and circular voids. Multiple reinforcing bars of any size and location. Reinforcing bar library. Numerous methods of quickly generating bar layouts. Calculation and display of interaction curves for the actual reinforcement, and for other reinforcement percentages that you specify. Calculation of load factors for X-axis, Y-axis and biaxial bending. Calculation of multiple load cases simultaneously. Calculation of moment magnifiers. Calculation and checking of code minimum design moments. Allowance for tension and compression. Allowance for positive and negative moments. Automatic transfer of column geometry, including cross section shape from your frame analysis model. Automatic transfer of loads from your frame analysis model. Allowance for input of extra user-defined load cases. Various unit sets.

See also Concrete column assumptions and notes.

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Running a concrete column design You can perform a concrete column design by clicking the members you wish to design, clicking the right mouse button and then selecting "Concrete Column Design" from the floating menu that appears.

Shape selection These buttons allow you to select a column cross section shape. Non-standard shapes You can use multiple rectangular or circular voids with any of the standard shapes to create almost any type of non-standard shape such as columns with holes, lift cores, shear walls, etc. Clear Resets all of the data in the form to default values.

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Configure Allows you to enter the configuration form where you are able to adjust a number of parameters and settings. The specific fields are described later in this document (see also Concrete column configuration). Print Allows you to print graphics, design data and the interaction curve points (see also Concrete design report). Check Performs a check of the column for the shape, reinforcement and loads you have defined. This includes calculation of the interaction diagrams, load factors, slenderness and moment magnifiers, etc. Auto-check mode If activated, a check will automatically be performed whenever you change some data. It operates exactly the same as if you clicked on the Check button after every change you made. You may wish to turn this off when the module is taking a long time to perform calculations. See also Concrete column assumptions and notes. Design Performs a design of the column which modifies the reinforcing bar sizes to satisfy the reinforcement percentage range, loads and load factor limit you have defined. It does not move, add or remove bars, it merely changes their size. Note that all bar sizes will be changed to the same size. See also Concrete column assumptions and notes. Units The units system you wish to use. Code The design code you wish to use.

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SPACE GASS 12 User Manual Concrete The concrete fields allow you to define the concrete strength and the column cross section shape dimensions. See also Concrete column assumptions and notes. F’c The characteristic concrete strength. Dimensions The dimensions for the selected shape. Note that all of the dimensions are pictorially represented via the small diagram above the Concrete fields. Bars These fields allow you to define the reinforcement sizes and layout. You can specify multiple reinforcement bars of different sizes within the column. See also Concrete column assumptions and notes. Add Allows you to add another bar. Delete Allows you to delete the currently selected bar. Generate reinforcement Allows you simply specify the number and size of bars in each cross section face, after which all bars are automatically generated. When you specify the number of bars in each face, keep in mind that the corner bars belong to just one face which is usually the horizontal face. For example, in order to specify four bars in each face of a rectangular column, you should specify four bars in the top and bottom faces and two bars in the side faces, resulting in a total of twelve bars. Note that this method of bar generation completely replaces all bars that were previously defined. Generate bars in a line Allows you to generate a line of bars in any direction.

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Note that this method of bar generation adds to the bars that were previously defined. Unify bar sizes Causes all of the bars to be changed to the size you specify. Bar The number and name of the currently selected bar. Note that the currently selected bar is circled in blue in the cross section diagram. D The bar diameter. X and Y The position of the bar relative to the upper left hand corner of the shape. Percentage The reinforcement range that you wish to design within. The module looks at this range when performing a design (ie. when you click the Design button) and will only choose a bar if its size falls within this range. Voids These fields allow you to specify multiple circular and rectangular voids. See also Concrete column assumptions and notes. Void The number of the currently selected void. Note that if multiple voids exist, the currently selected void is shown in blue in the cross section diagram. Add Allows you to add another void. Delete Allows you to delete the currently selected void. Type You can choose either rectangular or circular voids.

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SPACE GASS 12 User Manual D The void depth (if rectangular) or diameter (if circular). B The void width (if rectangular). X and Y The position of the void’s centroid relative to the upper left hand corner of the shape. Length The actual length of the column. kx and ky The effective length factors. These values are used to calculate the effective lengths of the column, where Lex = kx*L and Ley = ky*L. Braced (shrt / slnd) Specifies whether the column is braced or unbraced. If the column is fixed in position at its ends then you should tick the box. The value beside the braced item (ie. shrt / slnd) refers to the slenderness of the column. "Shrt" means that a column is short and "Slnd" means that the column is slender according to AS3600 clause 10.3. Loads Each load case consists of a description, axial force, bending moments and end moment ratios. During a design or check, the program considers all load cases simultaneously. If the structural model has been analysed, you can select specific load cases to be transferred to the concrete column design module. In addition, 10 blank "userdefined" load cases are created in the concrete column design module, ready for you to manually input forces and moments to supplement the transferred load cases. If the frame has not been analysed then only the 10 blank load cases are available. ! IMPORTANT NOTE ! Note that loads transferred from a SPACE GASS analysis are taken from the column ends only, regardless of whether any larger intermediate column loads exist or not

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See also Concrete column assumptions and notes. Load case description This allows you to select a load case to view. All of the moment, axial force, end moment, moment magnifier and ratio fields apply to the load case you select. The load factor for the selected load case is shown as follows the interaction diagram window (along with the load factor for the governing load case). Note that the load point for the current load case is circled in blue in the interaction diagram window. If the load point is displayed in red in the interaction diagram window then it indicates that the load factor is less than the load factor limit specified in the configuration form (usually set to 1.0). P Axial compression (+ve) or tension (-ve). See also Sign conventions. Mx Bending moment (either positive or negative) about the column’s local z-axis (shown as the horizontal axis in the concrete column module). A positive Mx causes compression at the top of the cross section. See also Sign conventions. My Bending moment (either positive or negative) about the column’s local y-axis (shown as the vertical axis in the concrete column module). A positive My causes compression at the left hand side of the cross section. See also Sign conventions. Mx1 / Mx2 and My1 / My2 The end moments used to calculate the reference L/r ratio when determining whether the column is short or slender. The ratio is positive when bent in double curvature (ie. M1 is the opposite sign to M2) or negative when bent in single curvature (ie. M1 and M2 are both the same sign). Ratio The ratio of the end moments. The module will calculate this value for you (given the end moments) or you can enter it directly.

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SPACE GASS 12 User Manual Apply moment magnification If activated, the moment magnifiers will be applied to the moments you specify. The calculated moment magnifiers and the magnified moments are displayed beside the moment fields. If the buckling load of the column has been exceeded for the currently selected load case then no moment magnifier will be shown, instead the word "buckled" will appear in red (and the moment will be multiplied by 10,000). Minimum load compliance If activated, the code’s minimum moments will be used if they are greater than the actual moments applied. If the moment (Mx or My) beside the multiplier is drawn in blue then the code defined minimum moment is being used. Check biaxial If activated, the module will consider biaxial effects in addition to the uniaxial effects.

The load factor for the current load case and the governing load case appear below the interaction diagram window with a code beside them indicating whether biaxial (B), x-axis (X) or y-axis (Y) moments govern. Interaction diagram window This is the large graph displayed on the left hand side of the form. The module constructs an interaction diagram (ie. Moment vs Axial force) for the section you define and then draws a point for every load case you have defined. The proximity of each load point to the interaction curve indicates whether the section can resist that load or not.

The concrete column module also optionally performs a biaxial check so that a point lying inside the curve does not necessarily indicate that the section has sufficient capacity. Note that the diagram will automatically change to show negative and positive moments dependant upon the sign of the currently selected load case moment. You can have both negative and positive moments displayed at the same time by changing the appropriate configuration setting (see also Concrete column configuration).

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The load factors for the currently selected load case and the governing load case are displayed below the bottom left hand corner of this window. A load factor displayed in red indicates that the load factor is less than the load factor limit specified in the configuration form. The maximum load factor value that will be displayed is 999.0. Load points drawn in red have a load factor less than the load factor limit specified in the configuration form. Finally, three special points are shown on the diagram. These points are: Ecc: Dec: Bal:

Point of Minimum Eccentricity (Code Defined) Point of Decompression (dn = D) Balance Point (Ku = 0.6)

Cross section window This window, located to the right of the interaction diagram window, displays the cross section and includes all reinforcing bars and voids. There is also a load position indicator in the centre of the diagram which indicates the direction of the moments and the eccentricity of the load. In many practical situations the load application point falls outside of the cross section in which cases the load position indicator simply points towards the load application point without showing its actual position. Mux / Muy These radio buttons, located immediately below the interaction diagram window, allow you to select between the x-axis and y-axis interaction diagrams.

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Concrete column configuration You can edit the concrete column design configuration by clicking the

button.

Min / Max bar dia The bar size range that the module will use (in addition to the reinforcement percentage range) when determining a suitable reinforcement size during a design. Tolerance (%) The accuracy of the load factor and neutral axis depth calculations. A smaller tolerance means the results will be more accurate, although the solution will take longer. Cover The cover that will be used when defining a standard reinforcement layout. Note that the cover is measured to the bar centre-lines. Beta d (G/(G+Q)) The ratio of dead load to dead+live load used when calculating the moment magnifier for an unbraced column. Lambda uc The uc factor from AS3600 clause 10.4.3.

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Concrete Column Design Load factor limit The acceptable load factor used to determine if the column is adequate for the given loads. A column is assumed to be adequate if the load factor (X, Y or Biaxial) for each load case is greater than or equal to the load factor limit. The default is 1.0. Calculate extra curves This allows you to calculate up to 4 extra reinforcement curves for the percentages you specify in the fields to the right. The distribution of reinforcement in the cross section for the extra curves is the same as for the specified reinforcement. Show positive and negative curves together Allows you to show both positive and negative interaction diagrams together. Comply with code reinforcement limits If activated, the module will apply the code’s minimum reinforcement requirements during a design if necessary. Show grid lines Turns on and off the grid lines in the interaction diagram window. Show special point values Turns on and off the numeric values for the special points shown in the interaction diagram window.

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Concrete column design results You can generate a report of the column design by clicking the

button.

Graphics This includes the interaction diagram, the column cross section, and some of the key input and output design parameters. The content of the printed interaction diagram will depend upon how it is displayed on the screen; so if you wish to display multiple reinforcement curves in the report then you should make sure they are displayed on the screen. This also applies to the special point values, grid lines, etc. Design data The design data report includes full details of the reinforcing bars, loads, and design results for each load case. Values of bending moment, axial force, kx, ky, and  are also included for each of the special points. The special points are explained as follows: Ecc Dec Bal M=0 N=0

- Point of Minimum Eccentricity (Code Defined) - Point of Decompression (dn = D) - Balance Point (Ku = 0.6) - The point where the curve crosses the vertical axis - The point where the curve crosses the horizontal axis

Interaction points This produces a table of bending moment versus axial force values for each of the points that make up the interaction curve. The values of kx, ky, and  are also included for each point. The special points are also labelled for easy reference.

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Concrete column assumptions and notes The following assumptions and notes should be noted when using the concrete column design module. 1.

Calculations involving shapes that have voids which overlap may not be accurate.

2.

Calculations involving bars that fall within a void or outside the cross section may not be accurate.

3.

Calculations involving bars that overlap may not be accurate.

4.

The program does some approximate checks for bars or voids that fall outside of the cross section, however these checks are not exhaustive and it is up to you to verify visually that none of these conditions occur.

5.

In certain circumstances, usually where the balance point is near to zero, there will be a step increase in the moment capacity (it will appear as a bump in the interaction diagram). This is because there is not a gradual increase in the strength reduction factor from 0.6 to 0.8.

6.

Sometimes, particularly in sections with very small dimensions, the curve may not appear to be a continuous line. This is due to insufficient convergence of the calculations. Try decreasing the tolerance in the configuration form.

7.

Calculation speed can usually be increased by turning off the calculation of extra reinforcement curves in the configuration form.

8.

The module does not consider true biaxial moment, rather it considers the moments uniaxially and then performs a simple biaxial check in accordance with AS3600 clause 10.6.5.

9.

If the buckling load (Nc) has been exceeded, the moment magnifier will be inappropriate and the term "Buckled" will appear beside the final moment field. This is because a moment magnifier cannot be calculated if a column’s buckling load has been exceeded.

10. A load factor of 999.0 indicates that the actual load factor is greater than or equal to 999.0. 11. A load factor drawn in red indicates failure.

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SPACE GASS 12 User Manual 12. The calculation of the strength reduction factor considers parts (a), (b)(i) and (b)(ii) of AS3600 table 2.3 only. 13. The cracked moments of inertia and cracked modulus of elasticity are not used. 14. The module calculates both of the moment magnifiers (Delta s and Delta b) and uses the largest (where appropriate). See AS3600 clause 10.4. 15. A column is bent in single curvature when the ratio of the end moments M1/M2 is positive and double curvature when the ratio is negative. 16. Torsion or shear are not considered. 17. Cover is measured to the centre-line of the bars.

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Output Output Text and graphics reports can be viewed or printed. Print previews can be obtained and the page setup form gives you full control over the printer selection, paper size, orientation, margins, layout, scales and output format. You can initiate a report by clicking the toolbar button or selecting the Output menu. You can then choose between viewing a text report, printing a text report or printing graphics. For text reports, the output can be limited to just input data or just output data and even to specific nodes, members, section properties and load cases if required. You can also limit the output to the data specified in any of the graphical filters.

Prior to generating a report, you must choose the items that you want to include in the report by selecting the appropriate check boxes in the above form. You can turn a whole column of check boxes on or off by clicking the "All on" or "All off" buttons at the bottom of the form. After completing your selections, you can proceed to the following form.

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Filters You can select from any of the graphical filters to limit the output report to the data defined in a filter. Alternatively, you can select "Use Filter Selected in Main Toolbar" so that the data included in the output report always matches what is shown in the graphics display area. You can also further limit the output data by specifying lists of nodes, members, section properties, load cases, etc. If you want to include all items for a particular

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Output list then the list field should be left blank, otherwise type in a list of items (separated by commas or dashes) that you want to include in the report. Format Output can be printed in fixed point format (eg. 12.45) or exponential format (eg. 1.245E+01). Fixed point is generally preferred as it is easier to read and allows numbers with different orders of magnitude to be readily identified. It cannot, however be used with very large or very small values. In such cases, exponential format must be used. As well as specifying the format, you can select the number of decimal places to be included. This cannot be greater than 3 for exponential formatting and cannot be greater than 8 for fixed point formatting. These limits are imposed because of a maximum 10 digit field width. Care must be taken when specifying the number of decimal places with fixed point format. You must ensure that for the range of values likely to be encountered, you don't exceed the 10 digit field width. For example five decimal place fixed point format could only handle values from 999.99999 to 9999.99999. Values outside of this range would simply be printed as "**********". Section and material properties are always presented in exponential format regardless of the format you specify (due to the extreme range of values usually encountered). Enveloping The analysis results data for each load case can be printed separately or can be combined into a load case envelope. If a load case envelope is specified, the program selects and prints the maximum and minimum values from the list of specified output load cases. The report also includes the load case numbers and the matching coincident values that occur at the same location and load case as each maximum and minimum. At the end of an envelope report is a summary envelope showing the maximums and minimums for a group of nodes and/or members. The summary report also shows the load case numbers and the matching coincident values. Envelope summary only By default, envelope reports include an envelope summary at the end, however you can limit your report to just the summary by activating this option in the report generation form.

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SPACE GASS 12 User Manual Member end A or end B For member end forces and moments, if you wish to limit your envelope to the maximums and minimums that occur at just one particular member end (rather than from either end), you should tick "Member End A" and/or "Member End B". If you tick "Either Member End" (the default setting) then the maximums and minimums will be taken from either end. The enveloping tool is a fast and convenient way of determining the critical load cases, nodes, members and plates, regardless of the size of the job. Include warnings This check box allows you to suppress warning messages relating to the analysis results which sometimes appear in output reports. For example, if a non-linear analysis does not reach the requested convergence in some load cases, then warning messages are posted in the output report for those load cases. Intermediate stations SPACE GASS can print the displacements, forces and moments at any intermediate points along a member (not just at the end nodes). Before intermediate member displacements, forces and moments can be printed, you must specify how many equally spaced intermediate member stations are to be considered. The program automatically adds an extra station at each end of the member and at each point of application of a concentrated member load. Sorting options Analysis results output can be sorted in one or both of two ways. 1. If sorted in order of load case, the report lists the data for every node (or member) under a main load case heading. This is repeated for each load case.

2. If sorted in order of node/member, the report lists the data for every load case under a main node (or member) heading. This is repeated for each node (or member). Member symbols notation Steel member design reports allow you to optionally include a summary sheet of the symbols used in the report together with a brief description of each.

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Output Member section properties This allows you to specify whether or not full section properties for the designed or checked members are included in the output. This option is usually suppressed because it enlarges the size of the report. Non-critical load cases The majority of the report for a steel member design gives information about the governing failure mode and the critical load case. A summary showing the performance of all of the other load cases can also be included if required. The non-critical load cases summary includes the load factor and the failure mode for each load case.

A description of the failure mode for each load case does not necessarily indicate that failure has occurred. It simply indicates the failure mode if the loads were increased enough to cause failure. Connection symbols notation Steel connection design reports allow you to optionally include a summary sheet of the symbols used in the report together with a brief description of each. Connection specifications This allows you to include or suppress the list of detailed specifications for the bolts, plates, welds, stiffeners and cleats from the detailed output reports. Connection calculations This setting allows you to include or suppress the loads, stresses, capacities, factors and other calculated values from the detailed output reports. Warnings and notes This check box allows you to suppress warning messages and notes relating to the design results which sometimes appear in output reports. Pass/fail criteria For output of steel member and connection design results you can set the "Pass/fail criteria" value to include only the members/connections which have passed, only the ones which have failed, or all members/connections. After completing the fields in the above form, you can click the Ok (if viewing), Print, Print preview or Page setup buttons.

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Page setup You can access the page setup form by selecting "Page Setup" from the File menu or clicking the "Page Setup" button on the "Print Text Report" or "Print Graphics" forms. The page setup form gives you full control over the printer selection, paper size, orientation, margins, layout, scales and output format for both text and graphics. There are separate tabs for text and graphics settings, however if the "Keep text and graphics common items the same" check box is selected then items that are common to both text and graphics only need to be changed in one tab rather than both.

If you want the text and graphics settings to be different then you must deselect the "Keep text and graphics common items the same" check box before making the changes. If you want to include your own logo in printed output, you should create a logo image file in JPG format, install it with the SPACE GASS utility tool, and then select either of the "Logo on first page only" or "Logo all pages" check boxes in the page setup form below. For best results, make the image file large enough so that it contains enough pixels for a printer resolution of 300 dpi or more. For example, if your printer operates at 600 dpi and you want the printed logo height to be 20mm, your logo image file will need to be at least 472 pixels in height (ie. 600/25.4x20). Regardless of the size of your logo image file, it will be scaled to print at the exact height you specify in the page setup form.

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Output

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Output

View text report You can view a text report by clicking the toolbar button and then selecting "View Text Report" from the floating menu, or selecting "View Text Report" from the Output menu. You must first select the data that you want to view, after which the report viewer is displayed as follows.

The report viewer allows you to view any of the input or output data in an easy-toread format. The side menu lets you go directly to any part of the report or hide any sections of the report before printing via the button located just above the side menu.

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Print preview You can generate a print preview by clicking the "Print Preview" button in the "View Text Report", "Print Text Report" or "Print Graphics" forms. The print preview allows you to see exactly how the output will appear on your printer. For text reports, the side menu lets you go directly to any part of the report or hide any sections of the report before printing. You can output direct to the printer or you can output to a text, PDF, HTML or picture file.

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Output

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Output

Print text report You can print a text report by clicking the toolbar button and then selecting "Print Text Report" from the floating menu, or selecting "Print Text Report" from the Output menu. You must first select the data that you want to print, after which the print is produced.

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Print graphics You can print graphics by clicking the toolbar button and then selecting "Print Graphics" from the floating menu, or selecting "Print Graphics" from the Output menu.

Scale Specify the desired hardcopy scale or leave it at zero for automatic scale to fit. For example, type in a value of 100 for a 1:100 scale. Title This is simply a description which you can use to describe the particular view that is being printed. It is placed near the bottom-left corner of the hardcopy and can be left blank if it is not required.

After completing the fields in the above form, you can click the Print, Print preview or Page setup buttons.

792

Output

The status report A status report showing the actual problem size and the problem size limits can be included at the start of each output report. It shows the number of nodes, members, restraints, sections, materials, constraints, loads, load cases and members with design data. It also shows the static and dynamic analysis status, ill-conditioning status, non-linear convergence, frontwidth, total degrees of freedom, whether there has been a steel or concrete design or check and the design code used. The status report can be suppressed if it is not required.

793

Standard Libraries Standard libraries SPACE GASS is supplied with libraries of standard sections, materials, bolts, plates, welds, spectral curves, reinforcing bars and moving load vehicles. The libraries can be accessed by SPACE GASS for rapid and convenient input of standard properties. They are also scanned frequently during analysis and design operations. You can get access to the libraries and retrieve data via the built-in library editor by clicking the button at various locations throughout SPACE GASS. You can also access the library editor by choosing "Edit Libraries" from the File menu. The library editor is shown below.

795


You cannot modify any of the standard libraries supplied with SPACE GASS, however you can create your own custom libraries and edit them without restriction. You can also copy data from the standard libraries into your custom libraries. For more information, refer to The library editor.

796

Standard Libraries

The library editor You can open the library editor from the File menu or by clicking the button from various places within SPACE GASS. If opened from the File menu, the library editor gives you access to all types of library data (eg. sections, materials, bolts, plates, welds, reinforcing bars, spectral curves and moving load vehicles). If opened via the button from an area of SPACE GASS that is working with a specific type of data (eg. section property data), the library editor gives you access only to the applicable library types (eg. section property libraries).

797


Custom libraries You cannot edit or delete standard libraries (shown black in the library tree), however you can create and edit your own custom libraries (shown blue in the library tree). To create a custom library, click the appropriate library type in the library tree (eg. Section Libraries) and then click the "Add Library" button at the bottom of the library editor. Alternatively, you can right-click on "Section Libraries" in the tree and then select "New Library".

Similarly, for section libraries you can add groups (sub-categories) by clicking the "Add Group" button at the bottom or by right-clicking on the custom library name and then selecting "New Group".

Once a custom library has been created, you can add data by clicking the appropriate "Add" button at the bottom or by right-clicking on the custom library, selecting the appropriate "New" item and then entering the required data. For section libraries, new sections can be added via the shape builder which automatically opens when you click the "Add Section" button. Sections can also be edited by clicking the shape builder button library editor.

798

near the top-right corner of the

Standard Libraries You can also drag library items from a standard or custom library into a custom library. For section libraries, you can even drag a whole group into a custom library. If you hold down the Ctrl key while dragging then the items will be copied rather than being moved.

For information on how to import or export library data in other formats, refer to Importing and exporting. For information on how to import SPACE GASS 10 or older libraries, refer to Importing old libraries.

799


Importing and exporting Data can be imported into custom libraries or exported from standard or custom libraries by opening the library editor, right-clicking on the desired library in the library editor tree and then selecting the appropriate Import or Export option. If you wish to create a custom library by importing data from another source, it must be in a text or MS-Excel file formatted correctly for SPACE GASS. If you are not sure what the correct format is, you should export one of the standard SPACE GASS libraries to a file and then open the file to see how it is formatted and then use that as a pattern for the file you wish to import. For information on how to import SPACE GASS 10 or older libraries, refer to Importing old libraries.

800

Standard Libraries

Importing old libraries If you have custom libraries in SPACE GASS 10 or earlier formats, you can import them into the current version of SPACE GASS by opening the library editor, rightclicking on the desired library type in the library editor tree, selecting Import -> From Library and then locating and selecting the library to be imported. Note that SPACE GASS 10 custom libraries are always called SGCustomLib.MDB (or SGMoveC.dat for moving load vehicles) and are usually located in the SPACE GASS 10 program folder (c:\Program files (x86)\SPACE GASS\Exe or c:\Program files\SPACE GASS\Exe).

801


Section libraries Section libraries contain the geometric and strength information for the sections they contain. This includes the section name, shape type, section properties, dimensions, fabrication type and material strengths. Section libraries are now capable of holding non-standard sections and sections built from up to 10 shapes. When importing section data from another source into a SPACE GASS section library, if you are not sure what the correct format is, you should export one of the standard SPACE GASS libraries to a file and then open the file to see how it is formatted and then use that as a pattern for the file you wish to import. Note the following requirements for section property data. 1. For sections that have webs or flanges, the y-axis is parallel to the web(s) and the z-axis is parallel to the flange(s). For other sections the y-axis is the vertical axis and the z-axis is the horizontal axis. The y and z axes generally correspond to the minor and major axes respectively, however this is not always the case. 2. Moments of inertia and plastic section modulii are for the principal axes. 3. The principal angle is positive when the principal axes are rotated anticlockwise with respect to the non-principal axes when looking at the cross section from a member's node A end towards its node B end. Note that the sign of the principal angle is shown reversed in the shape builder. 4. The centroid dimensions are the distances from the shape's reference point to the centroid along the y and z axes. Reference points are shown as a red dot in the image for each shape type in the Shape builder. 5. For column Tee sections, the dimensions are orientated the same as for beam Tee sections (ie. the depth is parallel to the web) even though column Tees are rotated through 90 degrees compared to beam Tees when used in a SPACE GASS model. 6. The "Section type" field must conform to one of the following: Circular Bar Square Bar Rectangular Bar

802

Standard Libraries Circular Tube Square Tube Rectangular Tube I or H Section Plate Web Girder Channel Beam Tee Column Tee Equal Angle Unequal Angle Cruciform Box Girder Wedge Slice Fillet Points Shape LiteSteel Beam LSB Back-to-Back Lines Shape Triangle Cee Shape Zed Shape Top Hat Double Angled Short Double Angled Long Double Angled Starred Polygon Polygon Tube Equilateral Triangle Schifflerized Angle

803


Material libraries Each material in a standard material library contains the following information. 1. Young’s modulus 2. Poisson’s ratio 3. Mass density 4. Thermal coefficient 5. Concrete strength

804

Standard Libraries

Bolt libraries Each bolt in a standard bolt library contains the following information. 1. Diameter 2. Tensile strength (normal strength) 3. Tensile strength (high strength) 4. Tensile stress area - Cross-sectional area for calculating tensile stress 5. Shank area - Plain shank cross-sectional area 6. Core area - Core cross-sectional area 7. Minimum tension - Minimum bolt tension at installation

805


Plate libraries Each plate in a standard plate library contains the following information. 1. Width 2. Thickness 3. Yield stress (normal strength) 4. Tensile strength (normal strength) 5. Yield stress (high strength) 6. Tensile strength (high strength)

806

Standard Libraries

Weld libraries Each weld in a standard weld library contains the following information. 1. Size 2. Tensile strength (normal strength) 3. Tensile strength (high strength)

807


Reinforcing bar libraries Each bar in a standard reinforcing bar library contains the following information. 1. Diameter 2. Yield strength 3. Area

808

Standard Libraries

Spectral curve libraries Each curve in a standard spectral curve library contains the following information. 1. Damping factor (%) 2. Period, acceleration point pairs

809


Vehicle libraries Each vehicle in a standard vehicle library contains the following information. 1. Vehicle name 2. X, Y and load data for each wheel, where X is the distance back from the front of the vehicle to the wheel, and Y is the distance sideways from the centerline of the vehicle to the wheel.

810

Portal Frame Analysis Portal frame analysis This worked example considers the analysis of a typical 25m span haunched portal frame. Linear (1st order), non-linear (2nd order), dynamic (frequency and response) and buckling analyses have been performed and the results are presented in the computer printout at the end of this appendix. This appendix considers only the analysis of the portal frame. The portal frame member and connection design is covered in Portal frame member design and Portal frame connection design. This example is loosely based on the design example used in the AISC publication by Woolcock, Kitipornchai and Bradford (9). There are, however a number of significant differences between this example and the AISC example which can be summarized as follows. 



  

Because SPACE GASS has facilities for projected length member loads, the live load has been input over the plan rafter length rather than its inclined length. This was a situation that the software used in the AISC example could not model. Because SPACE GASS has facilities for automatically calculating haunch section properties based on the rafter size and the size of the member from which the haunch was cut, the haunch section properties are different. The AISC example simply approximates the haunch to a 530UB82 for half of its length and a 410UB60 for the other half. SPACE GASS uses a value for gravitational acceleration of 9.8066, the AISC example uses 9.82. SPACE GASS uses grade 300 steel, whereas the AISC example uses grade 250 steel. The purlins used in the AISC design example are assumed to be spaced at a maximum of 1500mm, while the structural drawings elsewhere in the publication show them to be spaced at 1200mm maximum. This SPACE GASS example uses purlin spacings of 1200mm as they are shown in the drawings.

Because the members in the AISC example have been designed by hand, they have not been able to take full advantage of some of the more calculation intensive and

811

SPACE GASS 12 User Manual slightly more efficient higher tiers offered by the SPACE GASS steel member design module.

The differences between this example and the AISC example prohibit the direct comparison of results. However, if you wish to do so, you should first modify the SPACE GASS example in accordance with the differences listed above. If you do the modifications, you will find that the results of the two examples agree almost exactly.

812


Geometry and loads The portal frame considered in this example has the following basic properties. Building length: Portal span: Portal spacing: Eave height: Apex height: Columns: Rafters: Haunches: Roof and walls: Static load data Dead load (DL):

72m 25m 9m 7.5m 8.155m (3 roof pitch) 530 UB 92.4 360 UB 50.7 360 UB 50.7 (3m long) Trimdek 0.47 sheeting

Sheeting and purlins 0.90kN/m (slope) Self weight (calculated by SPACE GASS)

Live load (LL):

2.25kN/m (plan) 4.5kN concentrated at apex

Cross wind (CW): (external)

6.30kN/m on windward columns 4.50kN/m on leeward columns 6.48kN/m uplift on windward 8m of rafter 3.60kN/m uplift on central 8m of rafter 2.16kN/m uplift on leeward remainder of rafter

Longit. wind (LW1): (1st internal frame)

4.14kN/m outward on columns 5.04kN/m uplift on rafters

Longit. wind (LW2): (external suction)


Cross wind (IPCW): (Internal pressure)


Longit. wind (IPLW): (Internal pressure)


813

SPACE GASS 12 User Manual Load combination 1: Load combination 2: Load combination 3: Load combination 4: Load combination 5:

1.25DL + 1.50LL 0.80DL + CW + IPCW 1.25DL + CW - 0.96IPCW (ISCW) 0.80DL + LW1 + IPLW 1.25DL + LW2 - 6.50IPLW (ISLW)

The distributed live load is based on a roof area of 9m x 25m = 225sqm which requires a distributed live load of 0.25kPa. The wind loads are based on terrain category 3 (industrial area) for region B with Vu = 60m/s and Vs = 38m/s. Taking into account the height of the rafters and purlins (200mm), the eaves height is assumed to be 8m and the apex height is assumed to be 8.7m. Dynamic frequency mass data Dead load (DL): Self mass (calculated by SPACE GASS) Sheeting and purlins 91.77kg/m (slope) Live load (LL):

229.43kg/m (plan) 458.86kg concentrated at apex

Total distributed mass:

91.77 + 229.43 = 321.20kg/m

Mass at nodes 3 and 11: Mass at nodes 4 and 10: Mass at nodes 5 and 9: Mass at nodes 6 and 8: Mass at node 7:

1.63/2.0*321.20 = 0.26 tonne 1.63*321.20 = 0.52 tonne (1.63/2.0+2.99/2.0)*321.20 = 0.74 tonne (2.99/2.0+6.26/2.0)*321.20 = 1.49 tonne 6.26*321.20+458.86 = 2.47 tonne

Dynamic response data Spectral curve: Damping: Dynamic modes: Direction vector: Loading code: Vertical direction: Sign of the results: Base shear: Site factor: Acceleration factor:

814

1989 Newcastle earthquake, magnitude 6.5 5% 1,2 and 3 Dx=1.0, Dy=0.0, Dz=0.0 General Y-axis Signed to match first dynamic mode Not less than 80% of total static force 2.0 0.08

Portal Frame Analysis Importance factor: Structural response factor: Spectral curve multiplier: Mode combination method:

1.0 4.5 0.017778 SRSS

Load combinations The static load combinations are in accordance with typical strength limit state stipulations (excluding earthquake loading) as follows. 1. 2. 3. 4.

1.25G + 1.5Q 1.25G + Wu 0.80G + 1.5Q 0.80G + Wu

While these load combinations are no longer in line with AS1170, they have been retained for compatibility with the AISC publication on which this example is based.

In this worked example it has been assumed that the distributed live load in load case 2 need not be considered to act simultaneously with any wind load. The structure will be designed to support either the distributed live load or the wind load, whichever produces the most critical effect. Notes on the structure Extra nodes have been positioned at mid-height of the columns and at midspan of the rafters. This is not absolutely necessary but it means that graphical displays will automatically show the values of forces and moments at these points. Of course you can obtain the deflections, forces and moments at these points without having to have nodes there by simply scaling them off the diagrams or by obtaining an intermediate displacements, forces and moments report, however these methods may sometimes be less convenient than having the values displayed graphically. Nodes have also been positioned at the mid-points and end-points of the haunches. These are necessary so that the section properties can be varied along the haunch. In the above example, the haunch has been modelled as a tapered 360 UB 50. Only two prismatic members were used to approximate the tapered haunch because tests have shown that this gives results very close to the exact solution. If you wish to experiment with this, try inputting some frames with varying numbers of haunch segments, and compare the results of the deflections and bending moments.

815


In fact, haunches do not have much effect at all on the bending moments in other parts of the frame, however they do eliminate the need to design the rafters for the high bending moments which usually occur at the knee. Haunches can also offer significant reductions in deflection of the frame. The frame, as modelled in SPACE GASS, is shown in the following diagrams.

Basic arrangement of nodes and members

816


Frame elevation

817


Method of input The portal frame in this example was initially input as a single bay portal frame using the structure wizard. This allowed quick and easy generation of the basic structural geometry, restraints, section properties (including the haunch section properties) and material properties. If the extra column and rafter nodes were not required, it would then have been a simple matter to add the loads (graphically or using datasheet input) and then perform the analysis. Node, member and plate numbering In this example we wanted to match the node, member and plate numbering with the numbering used in the AISC example. Therefore, it was necessary to modify the geometry slightly so that the extra nodes were added and the nodes and members were re-numbered. This was done graphically by simply subdividing the members and then renumbering the structure with the extra nodes included. The rafter and haunch section properties were assigned to members 3 - 10 by graphically changing the section property numbers of members 5, 6, 7 and 8 to section 2, members 3 and 10 to section 3, and members 4 and 9 to section 4. Node restraints When the structural geometry was established, node restraints of FFFRFR were applied to support nodes 1 and 13, and restraints of RRFRRR were applied to rafter nodes 3, 6, 7, 8 and 11. The restraints on nodes 1 and 13 specified that the structure was pin-based, allowing rotation about both the X and Z axes. The standard 2D frame pin restraint of FFFFFR was not used in this case because it would have prevented rotation about the X-axis. The rafter node restraints were applied to simulate the effect of wall and roof bracing that would prevent any out-of-plane (Z-axis) movements at those nodes. A general restraint of RRFRRR was not used in this case because it would have prevented the out-of-plane movements of nodes 2, 4, 5, 9, 10 and 12 which, in real life, would be free to move in that direction. Although no out-of-plane movements would occur in a static analysis (due to no loads in that direction), they could occur in a buckling analysis and, if restrained, could result in incorrect buckling load factors and effective lengths. If no intermediate nodes were present that could move in the out-of-plane directions then a general restraint could have been used.

818


Under normal circumstances it would not have been necessary to match the node and member numbering with the AISC example. This would have removed the necessity to subdivide the members, or change the member properties and node restraints as described above. Loads The node and member loads were applied graphically. Although there are many member loads, the graphical input facility made it very easy to input them enmasse. For most load cases, it was simply a matter of placing a window around the members and then specifying the load applied to them. Self weight, combination load cases and load case titles were input using datasheets. Input check As a final check before the analysis was initiated, loading diagrams for each load case were viewed followed by an output report of the complete structural data. Any errors in the data were corrected and the model was then ready for analysis.

819


Analysis procedure Linear analysis The first analysis to be performed was a linear analysis for the primary load cases 1 - 7. The results of this analysis were used to check frame deflections. Non-linear analysis Load cases 10 - 14 were analysed in a second run because the steel member design example is based on factored combination load cases analysed non-linearly. Both P- and P- effects were activated, while axial shortening wasn’t. The linear analysis results for the primary load cases were retained and the stiffness matrix was written to the disk.

A general optimization method was used, however this had little impact on the analysis time due to the small size of the model. Dynamic frequency analysis The self mass of the portal frame was considered in association with mass load case 8 (which incorporated the lumped masses due to both dead and live loading conditions). Six mode shapes were requested. Dynamic response analysis The dynamic response analysis was performed for spectral load case 9. The sign of the results was determined automatically and all results were retained for those load cases analysed linearly or non-linearly. Buckling analysis The default options were selected for the buckling analysis (ie. only one mode shape was calculated).

820


Analysis results The following summary was developed based upon the results: Maximum sway deflection: Maximum vertical deflection: Maximum moment (column - knee): Maximum moment (rafter - haunch): Maximum moment (apex): Minimum frame buckling load factor: Natural frequencies (first 6 frequencies):

99mm (load case 3) 119mm (load case 4) 527kNm (load case 11) 211kNm (load case 11) 127kNm (load case 11) 8.23 (load case 14) 0.86, 1.82, 4.88, 6.27, 6.28, 6.76 Hz

The dynamic response spectrum analysis resulted in small displacements, forces and moments that were insignificant in comparison with the static load cases. The results of the non-linear analysis were then used to perform a steel member check and a steel connection design. As an interesting exercise, the results of the non-linear analysis were then compared with the results of a linear analysis of the combination load cases. Load case 11 was still found to be critical with the new moments being 542kNm at the knee, 223kNm at the end of the haunch and 132kNm at the apex. You can see that the linear moments are actually greater than the non-linear moments. This is also shown in the AISC example.

821


Graphical output The following diagrams are examples of the graphical output that can be obtained from SPACE GASS on the screen or printer.

Basic arrangement of nodes and members

Loading diagram (load case 3)

822


Deflection diagram (load cases 2, 3 and 4)

Bending moment diagram (load case 10)

823

SPACE GASS 12 User Manual Bending moment diagram (load case 11)



824

Portal Frame Analysis Bending moment diagram (load case 14)

Bending moment diagram envelope (load cases 10-14)

Dynamic mode shape (load case 8)

825


Buckling mode shape (load case 12) – Note the out-of-plane buckling mode

826


Analysis input report This report extract shows all of the frame analysis input data, including lumped masses and spectral load cases. ANALYSIS STATUS REPORT ---------------------Job name ...... Portal Frame Worked Example Location ...... C:\Trunk\Shipping\Samples\Mixed This is a 2D portal frame analysed and designed worked example appendices. Length units ......................... m Section property units ............... mm Material strength units .............. MPa Mass density units ................... kg/m^3 Temperature units .................... Celsius Force units .......................... kN Moment units ......................... kNm Mass units ........................... kg Acceleration units ................... g's Translation units .................... mm Stress units ......................... MPa Nodes ................................ 13 Members .............................. 12 Plates ............................... 0 Restrained nodes ..................... 7 Nodes with spring restraints ......... 0 Section properties ................... 4 Material properties .................. 1 Constrained nodes .................... 0 Member offsets ....................... 4 Node loads ........................... 1 Prescribed node displacements ........ 0 Member concentrated loads ............ 0 Member distributed forces ............ 78 Member distributed torsions .......... 0 Thermal loads ........................ 0 Member prestress loads ............... 0 Plate pressure loads ................. 0 Self weight load cases ............... 2 Combination load cases ............... 5

for the SPACE GASS

( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( (

32765) 32765) 32765) 32765) 32765) 5000) 999) 32765) 32765) 250000) 250000) 250000) 250000) 250000) 250000) 250000) 250000) 10000) 10000)

827


Load cases with titles ............... Lumped masses ........................ Spectral load cases .................. Static analysis ...................... Dynamic analysis ..................... Response analysis .................... Buckling analysis .................... Ill-conditioned ...................... Non-linear convergence ............... Frontwidth ........................... Total degrees of freedom ............. Static load cases .................... Mass load cases ......................

14 18 1 Y N N Y N Y 12 65 8 2

( 10000) ( 250000) ( 10000)

STEEL DESIGN STATUS REPORT -------------------------Members with design data ............. Member design or check ............... Connections with design data ......... Connection design ....................

4 C 5 Y

( 32765) AS4100 ( 32765) AS4100

NODE COORDINATES (m) ---------------X Node Coord 1 0.000 2 0.000 3 0.000 4 1.630 5 3.260 6 6.250 7 12.500 8 18.750 9 21.740 10 23.370 11 25.000 12 25.000 13 25.000

Y Coord 0.000 3.750 7.500 7.585 7.671 7.828 8.155 7.828 7.671 7.585 7.500 3.750 0.000

MEMBER DATA (deg,kNm/rad,m)

828

Z Coord 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

( (

10000) 10000)


----------- (F=Fixed, R=Released) (*=Cable length) Dir Dir Dir Memb B Memb Angle Node Axis Type Node A Node B Sect Mat Fixity Length 1 0.00 Norm 1 2 1 1 FFFFFF 3.750 2 0.00 Norm 2 3 1 1 FFFFFF 3.750 3 0.00 Norm 3 4 3 1 FFFFFF 1.632 4 0.00 Norm 4 5 4 1 FFFFFF 1.632 5 0.00 Norm 5 6 2 1 FFFFFF 2.994 6 0.00 Norm 6 7 2 1 FFFFFF 6.259 7 0.00 Norm 7 8 2 1 FFFFFF 6.259 8 0.00 Norm 8 9 2 1 FFFFFF 2.994 9 0.00 Norm 9 10 4 1 FFFFFF 1.632 10 0.00 Norm 10 11 3 1 FFFFFF 1.632 11 0.00 Norm 11 12 1 1 FFFFFF 3.750 12 0.00 Norm 12 13 1 1 FFFFFF 3.750

Node A Node Fixity FFFFFF FFFFFF FFFFFF FFFFFF FFFFFF FFFFFF FFFFFF FFFFFF FFFFFF FFFFFF FFFFFF FFFFFF

NODE RESTRAINTS (kN/m,kNm/rad) --------------- (F=Fixed, R=Released, S=Spring, *=General) Rest X Axial Y Axial Z Axial X Rotation Y Rotation Z Rotation Node Code Stiffness Stiffness Stiffness Stiffness Stiffness Stiffness 1 FFFRFR 3 RRFRRR 6 RRFRRR

829


7 RRFRRR 8 RRFRRR 11 RRFRRR 13 FFFRFR

SECTION PROPERTIES (mm,mm^2,mm^4,deg) -----------------Sect Name 1 530 UB 92.4 Aust300 2 360 UB 50.7 Aust300 3 360 UB 50.7-A 4

360 UB 50.7-B

Area of Torsion Z-Axis Princ Sect Section Constant Area Angle 1 1.1800E+04 7.7500E+05 Infinite 0.00 2 6.4700E+03 2.4100E+05 Infinite 0.00 3 1.0845E+04 3.4719E+05 Infinite 0.00 4 9.7132E+03 3.2708E+05 Infinite 0.00 Sect Shape Tt/Tb Tw/Rr 1 I shape 15.60 10.20 15.60

830

14.00

Mark C1

Shape I shape

R1

I shape

S3

Multiple shapes User

S4

Multiple shapes User

Y-Axis

Z-Axis

Y-Axis

Mom of In

Mom of In

Shr Area

2.3800E+07 5.5400E+08

Infinite

9.6000E+06 1.4200E+08

Infinite

1.4404E+07 6.4354E+08

Infinite

1.4399E+07 3.6751E+08

Infinite

Trans Mir Rotate No

Source

No

0.00

D 533.00

Bt/Bb Btw/Bbw 209.00

0.00

209.00

0.00

Shr


2 I shape 11.50 7.30 11.50 11.40 3 I shape 11.50 7.30 11.40 Beam Tee 11.50 7.30

No

No

No

No

0.00

0.00

356.00

356.00

171.00

0.00

171.00

0.00

171.00

0.00

171.00

0.00

171.00

0.00

0.00

0.00

171.00

0.00

171.00

0.00

171.00

0.00

0.00

0.00

11.50

0.00 11.40 4 I shape 11.50 7.30 11.40 Beam Tee 11.50 7.30

No

No

No

No

180.00

0.00

333.10

356.00

11.50

0.00

No

No

180.00 178.002

11.40

MATERIAL PROPERTIES (MPa,kg/m^3,strain/degC) ------------------Young's Poisson's Mass Concrete Matl Material Name Modulus Ratio Density Strength 1 STEEL 2.0000E+05 0.25 7.8500E+03

MEMBER OFFSETS (m) -------------Memb Axes Dxa Dzb 3 L 0.000 0.000 4 L 0.000 0.000 9 L 0.000 0.000 10 L 0.000

Coeff of Expansion 1.170E-05

Dya

Dza

Dxb

Dyb

-0.168

0.000

0.000

-0.168

-0.106

0.000

0.000

-0.106

-0.106

0.000

0.000

-0.106

-0.168

0.000

0.000

-0.168

831


0.000

NODE LOADS (kN,kNm) ---------Load X-Axis Z-Axis Case Node Force Moment 2 7 0.000 0.000

Y-Axis

Z-Axis

X-Axis

Y-Axis

Force

Force

Moment

Moment

-4.500

0.000

0.000

0.000

MEMBER DISTRIBUTED FORCES (m,kN/m) ------------------------Load Sub Axes Start Start/ Z Start/ Case Memb Load Sys Position Finish Finish 1 3 1 GI 0.000% 0.900 0.000 0.900 4

1 0.000

0.900

0.000 5

1

0.900

0.000

0.900

0.000 6

1

0.900

0.000

0.900

0.000 7

0.900

Y

Position

Finish

100.000%

0.000

-

0.000

-

1

GI

GI

GI

GI

0.000%

0.000

-

0.000

-

0.000%

0.000

-

0.000

-

0.000%

0.000

-

0.000

-

0.000%

0.000

-

0.000

-

0.000

-

0.000

-

100.000%

100.000%

100.000%

100.000%

0.000

0.900

0.000 8

832

X Start/

0.000

0.900

0.900

Finish

1

GI

0.000%

100.000%

0.000


0.900

0.000 9

1

0.900

0.000

0.900

0.000 10

1

0.900

0.000

0.900 2 2.250

0.000 3

1

GI

GI

GP

0.000%

0.000%

0.000%

100.000%

100.000%

100.000%

0.000

-

0.000

-

0.000

-

0.000

-

0.000

-

0.000

-

0.000

-

0.000

-

0.000

-

0.000

-

0.000

-

0.000

-

0.000

-

0.000

-

0.000

-

0.000

-

0.000

-

0.000

-

0.000

-

0.000

-

0.000

2.250

0.000 4

1

2.250

0.000

2.250

0.000 5

1

2.250

0.000

2.250

0.000 6

1

2.250

0.000

2.250

0.000 7

1

2.250

0.000

2.250

0.000 8

1

2.250

0.000

2.250

0.000 9

1

2.250

0.000

2.250

0.000 10

1

2.250

0.000

2.250 3

0.000 1

1

GP

GP

GP

GP

GP

GP

GP

GP

0.000%

0.000%

0.000%

0.000%

0.000%

0.000%

0.000%

0.000%

100.000%

100.000%

100.000%

100.000%

100.000%

100.000%

100.000%

100.000%

6.300

833


0.000

0.000

0.000 2

0.000 1 GP 0.000

3

0.000 1 L 0.000

4

0.000 1 L 0.000

5

0.000 1 L 0.000

6

0.000 1 L 0.000

6

0.000 2 L 0.000

7

0.000 1 L 0.000

7

0.000 2 L 0.000

8

0.000 1 L 0.000

6.300

0.000

0.000%

100.000%

6.300 6.300

0.000 6.480

0.000%

100.000%

0.000 0.000

6.480 6.480

0.000%

100.000%

0.000 0.000

6.480 6.480

0.000%

100.000%

0.000 0.000

6.480 6.480

0.000

1.741

0.000 0.000

6.480 3.600

1.741

6.259

0.000 0.000

3.600 3.600

0.000

3.482

0.000 0.000

3.600 2.160

3.482

6.259

0.000 0.000

2.160 2.160

0.000%

100.000%

0.000 0.000

2.160 9 2.160

0.000 1 L 0.000

0.000%

100.000%

0.000 0.000

834


2.160 10 2.160

0.000 1 L 0.000

2.160 11 0.000

0.000 1 GP 0.000

0.000 12 0.000

0.000 1 GP 0.000

0.000%

100.000%

0.000 0.000

0.000%

100.000%

4.500 4.500

0.000%

100.000%

4.500 4.500

0.000 4

1

0.000 1 L 0.000

2

0.000 1 L 0.000

3

0.000 1 L 0.000

4

0.000 1 L 0.000

5

0.000 1 L 0.000

6

0.000 1 L 0.000

7

0.000 1 L 0.000

4.140

0.000%

100.000%

0.000 0.000

4.140 4.140

0.000%

100.000%

0.000 0.000

4.140 5.040

0.000%

100.000%

0.000 0.000

5.040 5.040

0.000%

100.000%

0.000 0.000

5.040 5.040

0.000%

100.000%

0.000 0.000

5.040 5.040

0.000%

100.000%

0.000 0.000

5.040 5.040

0.000%

100.000%

0.000 0.000

5.040 8

0.000 1 L

0.000%

100.000%

0.000

835


5.040

0.000

5.040 9 5.040

0.000 1 L 0.000

5.040 10 5.040

0.000 1 L 0.000

5.040 11 4.140

0.000 1 L 0.000

4.140 12 4.140

0.000 1 L 0.000

4.140 1

0.000 1 L 0.000

2

0.000 1 L 0.000

3

0.000 1 L 0.000

4

0.000 1 L 0.000

5

0.000 1 L 0.000

0.000 0.000%

100.000%

0.000 0.000

0.000%

100.000%

0.000 0.000

0.000%

100.000%

0.000 0.000

0.000%

100.000%

0.000 0.000

5 1.440

0.000%

100.000%

0.000 0.000

1.440 1.440

0.000%

100.000%

0.000 0.000

1.440 1.440

0.000%

100.000%

0.000 0.000

1.440 1.440

0.000%

100.000%

0.000 0.000

1.440 1.440

0.000%

100.000%

0.000 0.000

1.440 6 1.440

0.000 1 L 0.000

0.000%

100.000%

0.000 0.000

836


1.440 7

0.000 1 L 0.000

8

0.000 1 L 0.000

9

0.000 1 L 0.000

1.440

0.000%

100.000%

0.000 0.000

1.440 1.440

0.000%

100.000%

0.000 0.000

1.440 1.440

0.000%

100.000%

0.000 0.000

1.440 10 1.440

0.000 1 L 0.000

1.440 11 1.440

0.000 1 L 0.000

1.440 12 1.440

0.000 1 L 0.000

1.440 1

0.000 1 L 0.000

2

0.000 1 L 0.000

3

0.000 1 L 0.000

4

0.000 1 L 0.000

0.000%

100.000%

0.000 0.000

0.000%

100.000%

0.000 0.000

0.000%

100.000%

0.000 0.000

6 4.680

0.000%

100.000%

0.000 0.000

4.680 4.680

0.000%

100.000%

0.000 0.000

4.680 4.680

0.000%

100.000%

0.000 0.000

4.680 4.680

0.000%

100.000%

0.000 0.000

4.680 5

0.000 1 L

0.000%

100.000%

0.000

837


4.680

0.000

4.680 6

0.000 1 L 0.000

7

0.000 1 L 0.000

8

0.000 1 L 0.000

9 4.680

0.000 1 L 0.000

4.680 10 4.680

0.000 1 L 0.000

4.680 11 4.680

0.000 1 L 0.000

4.680 12 4.680

0.000 1 L 0.000

4.680 1

0.000 1 L 0.000

2

0.000 1 L 0.000

0.000

4.680

0.000%

100.000%

0.000 0.000

4.680 4.680

0.000%

100.000%

0.000 0.000

4.680 4.680

0.000%

100.000%

0.000 0.000

4.680

0.000%

100.000%

0.000 0.000

0.000%

100.000%

0.000 0.000

0.000%

100.000%

0.000 0.000

0.000%

100.000%

0.000 0.000

7 0.900

0.000%

100.000%

0.000 0.000

0.900 0.900

0.000%

100.000%

0.000 0.000

0.900 3 0.900

0.000 1 L 0.000

0.000%

100.000%

0.000 0.000

838


0.900 4

0.000 1 L 0.000

5

0.000 1 L 0.000

6

0.000 1 L 0.000

0.900

0.000%

100.000%

0.000 0.000

0.900 0.900

0.000%

100.000%

0.000 0.000

0.900 0.900

0.000%

100.000%

0.000 0.000

0.900 7

0.000 1 L 0.000

8

0.000 1 L 0.000

9 0.900

0.000 1 L 0.000

0.900 10 0.900

0.000 1 L 0.000

0.900 11 0.900

0.000 1 L 0.000

0.900 12 0.900

0.000 1 L 0.000

0.900

0.000

0.900

0.000%

100.000%

0.000 0.000

0.900 0.900

0.000%

100.000%

0.000 0.000

0.900

0.000%

100.000%

0.000 0.000

0.000%

100.000%

0.000 0.000

0.000%

100.000%

0.000 0.000

0.000%

100.000%

0.000 0.000

SELF WEIGHT (g's) ----------Load X-Axis Case Accel'n

Y-Axis Accel'n

Z-Axis Accel'n

839


1 8

0.000 0.000

-1.000 -1.000

0.000 0.000

COMBINATION LOAD CASES ---------------------Load case 10: 1.25DL+1.5LL 1.250 * Load case 1: Dead load (DL) 1.500 * Load case 2: Live load including 4.5kN at ridge (LL) Load case 11: 0.8DL+CW+IPCW 0.800 * Load case 1: Dead load (DL) 1.000 * Load case 3: Cross wind (CW) 1.000 * Load case 6: Cross wind internal pressure (IPCW) Load case 12: 1.25DL+CW+ISCW 1.250 * Load case 1: Dead load (DL) 1.000 * Load case 3: Cross wind (CW) -0.960 * Load case 6: Cross wind internal pressure (IPCW) Load case 13: 0.8DL+LW1+IPLW 0.800 * Load case 1: Dead load (DL) 1.000 * Load case 4: Longitudinal wind at first internal frame (LW1) 1.000 * Load case 7: Longitudinal wind internal pressure (IPLW) Load case 14: 1.25DL+LW2+ISLW 1.250 * Load case 1: Dead load (DL) 1.000 * Load case 5: Longitudinal wind with 0.2 external suction (LW2) -6.500 * Load case 7: Longitudinal wind internal pressure (IPLW)

LOAD CASE TITLES ---------------Load Case Title 1 Dead load (DL) 2 Live load including 4.5kN at ridge (LL) 3 Cross wind (CW) 4 Longitudinal wind at first internal frame (LW1) 5 Longitudinal wind with 0.2 external suction (LW2)

840


6 7 8 9 10 11 12 13 14

Cross wind internal pressure (IPCW) Longitudinal wind internal pressure (IPLW) Lumped masses (DL+LL) Spectral load case 1.25DL+1.5LL 0.8DL+CW+IPCW 1.25DL+CW+ISCW 0.8DL+LW1+IPLW 1.25DL+LW2+ISLW

LUMPED MASSES ------------Load Z-Axis Case Node Mass 8 3 0.000 4 0.000 5 0.000 6 0.000 7 0.000 8 0.000 9 0.000 10 0.000 11 0.000

(kg,kgm^2) X-Axis

Y-Axis

Z-Axis

X-Axis

Y-Axis

Mass

Mass

Mass

Mass

Mass

260.000

260.000

0.000

0.000

0.000

520.000

520.000

0.000

0.000

0.000

740.000

740.000

0.000

0.000

0.000

1490.000

1490.000

0.000

0.000

0.000

2470.000

2470.000

0.000

0.000

0.000

1490.000

1490.000

0.000

0.000

0.000

740.000

740.000

0.000

0.000

0.000

520.000

520.000

0.000

0.000

0.000

260.000

260.000

0.000

0.000

0.000

SPECTRAL LOAD DATA -----------------Load Mode Damping Case Shape Spectral Curve Factor 9 1 NEWCASTLE 5% 5.0%

Mass Case 8

Direction Vector Dx Dy Dz 1.000 0.000 0.000

841


2 3

NEWCASTLE NEWCASTLE Damping Spectral Curve Factor NEWCASTLE 5% 5.0%

842

5% 5%

5.0% 5.0%

8 8

1.000 1.000

0.000 0.000

Description Newcastle 1989, Dir=N-S, Mag=6.5

0.000 0.000


Static analysis report (itemised) This report extract shows the node displacements for primary load cases (1-9), the member forces and moments for combination load cases (10-14), and the node reactions for all load cases. Note that SPACE GASS lets you choose any desired load cases for each part of the report. Although load case 9 is a spectral load case rather than a static load case, it is also included in this part of the report because its results are in the same form as those of a static analysis. NODE DISPLACEMENTS (mm,rad) -----------------Load case 1 (Linear): Dead load (DL)

X-Axis Y-Axis Y-Axis Z-Axis Node Transl'n Transl'n Rotation Rotation 1 0.000 0.000 0.000 0.001 2 -3.443 -0.037 0.000 0.000 3 -1.988 -0.069 0.000 -0.001 4 -1.704 -3.152 0.000 -0.002 5 -1.392 -7.573 0.000 -0.003 6 -0.795 -19.423 0.000 -0.004 7 0.000 -35.597 0.000 0.000 8 0.795 -19.423 0.000 0.004 9 1.392 -7.573 0.000 0.003 10 1.704 -3.152

Z-Axis

X-Axis

Transl'n

Rotation

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

843


0.000 11

0.002 1.988

-0.069

0.000

0.000

-0.037

0.000

0.000

0.000 0.000 -0.001

0.000

0.000

0.000 12

0.001 3.443

0.000 13 0.000

0.000

Load case 2 (Linear): Live load including 4.5kN at ridge (LL) X-Axis Y-Axis Y-Axis Z-Axis Node Transl'n Transl'n Rotation Rotation 1 0.000 0.000 0.000 0.002 2 -6.194 -0.048 0.000 0.001 3 -3.698 -0.097 0.000 -0.003 4 -3.193 -5.540 0.000 -0.004 5 -2.629 -13.435 0.000 -0.006 6 -1.532 -35.183 0.000 -0.008 7 0.000 -66.190 0.000 0.000 8 1.532 -35.183 0.000 0.008 9 2.629 -13.435 0.000 0.006 10 3.193 -5.540 0.000 0.004 11 3.698 -0.097 0.000 0.003 12 6.194 -0.048 0.000 -0.001 13 0.000 0.000 0.000 -0.002

844

Z-Axis

X-Axis

Transl'n

Rotation

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000


Load case 3 (Linear): Cross wind (CW)

X-Axis Y-Axis Y-Axis Z-Axis Node Transl'n Transl'n Rotation Rotation 1 0.000 0.000 0.000 -0.018 2 63.213 0.117 0.000 -0.014 3 99.246 0.234 0.000 -0.004 4 98.835 -3.476 0.000 -0.001 5 98.245 -0.524 0.000 0.004 6 96.822 27.786 0.000 0.013 7 93.373 96.251 0.000 0.005 8 92.581 78.638 0.000 -0.010 9 90.748 42.540 0.000 -0.013 10 89.618 21.016 0.000 -0.013 11 88.460 0.084 0.000 -0.013 12 43.844 0.042 0.000 -0.012 13 0.000 0.000 0.000 -0.012

Z-Axis

X-Axis

Transl'n

Rotation

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

Load case 4 (Linear): Longitudinal wind at first internal frame (LW1) X-Axis Y-Axis Y-Axis Z-Axis Node Transl'n Transl'n Rotation Rotation 1 0.000 0.000

Z-Axis

X-Axis

Transl'n

Rotation

0.000

0.000

845


0.000

-0.003 10.251 0.100 0.000 -0.002 3 6.504 0.200 0.000 0.005 4 5.584 9.951 0.000 0.007 5 4.560 24.370 0.000 0.010 6 2.597 64.155 0.000 0.015 7 0.000 118.858 0.000 0.000 8 -2.597 64.155 0.000 -0.015 9 -4.560 24.370 0.000 -0.010 10 -5.584 9.951 0.000 -0.007 11 -6.504 0.200 0.000 -0.005 12 -10.251 0.100 0.000 0.002 13 0.000 0.000 0.000 0.003 2

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

Load case 5 (Linear): Longitudinal wind with 0.2 external suction (LW2) X-Axis Y-Axis Y-Axis Z-Axis Node Transl'n Transl'n Rotation Rotation 1 0.000 0.000 0.000 -0.001 2 2.808 0.029 0.000 0.000 3 1.823 0.057 0.000 0.001 4 1.565 2.772 0.000 0.002 5 1.278 6.813

846

Z-Axis

X-Axis

Transl'n

Rotation

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000


0.000 6

0.003 0.728

18.027

0.000

0.000

33.464

0.000

0.000

-0.728 18.027 -0.004 9 -1.278 6.813 0.000 -0.003 10 -1.565 2.772 0.000 -0.002 11 -1.823 0.057 0.000 -0.001 12 -2.808 0.029 0.000 0.000 13 0.000 0.000 0.000 0.001

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000 7

0.004 0.000

0.000

0.000

8

0.000

Load case 6 (Linear): Cross wind internal pressure (IPCW) X-Axis Y-Axis Y-Axis Z-Axis Node Transl'n Transl'n Rotation Rotation 1 0.000 0.000 0.000 -0.003 2 9.127 0.093 0.000 -0.001 3 5.925 0.186 0.000 0.004 4 5.087 9.010 0.000 0.007 5 4.154 22.143 0.000 0.009 6 2.365 58.586 0.000 0.013 7 0.000 108.759 0.000 0.000 8 -2.365 58.586 0.000 -0.013 9 -4.154 22.143

Z-Axis

X-Axis

Transl'n

Rotation

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

847


0.000

-0.009 -5.087 0.000 -0.007 11 -5.925 0.000 -0.004 12 -9.127 0.000 0.001 13 0.000 0.000 0.003 10

9.010

0.000

0.000

0.186

0.000

0.000

0.093

0.000

0.000

0.000

0.000

0.000

Load case 7 (Linear): Longitudinal wind internal pressure (IPLW) X-Axis Y-Axis Y-Axis Z-Axis Node Transl'n Transl'n Rotation Rotation 1 0.000 0.000 0.000 -0.001 2 1.755 0.018 0.000 0.000 3 1.139 0.036 0.000 0.001 4 0.978 1.733 0.000 0.001 5 0.799 4.258 0.000 0.002 6 0.455 11.267 0.000 0.003 7 0.000 20.915 0.000 0.000 8 -0.455 11.267 0.000 -0.003 9 -0.799 4.258 0.000 -0.002 10 -0.978 1.733 0.000 -0.001 11 -1.139 0.036 0.000 -0.001 12 -1.755 0.018 0.000 0.000 13 0.000 0.000

848

Z-Axis

X-Axis

Transl'n

Rotation

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000


0.000

0.001

Load case 8 (Linear): Lumped masses (DL+LL)

X-Axis Y-Axis Y-Axis Z-Axis Node Transl'n Transl'n Rotation Rotation 1 0.000 0.000 0.000 0.000 2 -1.257 -0.020 0.000 0.000 3 -0.716 -0.034 0.000 -0.001 4 -0.613 -1.166 0.000 -0.001 5 -0.500 -2.777 0.000 -0.001 6 -0.285 -7.050 0.000 -0.002 7 0.000 -12.848 0.000 0.000 8 0.285 -7.050 0.000 0.002 9 0.500 -2.777 0.000 0.001 10 0.613 -1.166 0.000 0.001 11 0.716 -0.034 0.000 0.001 12 1.257 -0.020 0.000 0.000 13 0.000 0.000 0.000 0.000

Z-Axis

X-Axis

Transl'n

Rotation

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

Load case 9 (Spectral) Spectral load case

X-Axis Y-Axis Y-Axis Z-Axis Node Transl'n Transl'n

Z-Axis

X-Axis

Transl'n

Rotation

849


Rotation 1 0.000 2 0.000 3 0.000 4 0.000 5 0.000 6 0.000 7 0.000 8 0.000 9 0.000 10 0.000 11 0.000 12 0.000 13 0.000

Rotation 0.000 0.000 0.000 0.142 0.000 0.000 0.255 0.001 0.000 0.257 -0.052 0.000 0.258 -0.105 0.000 0.258 -0.168 0.000 0.254 0.000 0.000 0.258 0.168 0.000 0.258 0.105 0.000 0.257 0.052 0.000 0.255 0.001 0.000 0.142 0.000 0.000 0.000 0.000 0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

MEMBER FORCES AND MOMENTS (kN,kNm) ------------------------Load case 10 (Non-linear): 1.25DL+1.5LL Non-linear (Small, Sec, Resid): P- P- 4 Itns, 99.988% Cnv (Res gov)

Y-Axis Memb Node Moment 1 1

850

Axial Z-Axis Force Moment 77.150

Y-Axis

Z-Axis

X-Axis

Shear

Shear

Torsion

-40.644

0.000

0.000


0.000 2 0.000 2

2 0.000 3 0.000

3

3 0.000 4 0.000

4

4 0.000 5 0.000

5

5 0.000 6 0.000

6

6 0.000 7 0.000

7

7 0.000 8 0.000

8

8 0.000 9 0.000

9

9 0.000 10 0.000 10 10 0.000 11 0.000 11 11 0.000 12

0.000 72.892 -153.483 72.892 -153.483 68.634 -305.488 44.163 -298.089 43.693 -196.504 43.728 -199.207 43.261 -112.024 43.249 -116.590 42.445 7.872 42.439 7.868 40.765 118.633 40.765 118.633 42.439 7.868 42.445 7.872 43.249 -116.590 43.261 -112.024 43.728 -199.207 43.693 -196.504 44.163 -298.089 68.634 -305.488 72.892

-40.644

0.000

0.000

-40.644

0.000

0.000

-40.644

0.000

0.000

66.421

0.000

0.000

57.393

0.000

0.000

57.365

0.000

0.000

48.514

0.000

0.000

48.523

0.000

0.000

33.220

0.000

0.000

33.230

0.000

0.000

1.242

0.000

0.000

-1.242

0.000

0.000

-33.230

0.000

0.000

-33.220

0.000

0.000

-48.523

0.000

0.000

-48.514

0.000

0.000

-57.365

0.000

0.000

-57.393

0.000

0.000

-66.421

0.000

0.000

40.644

0.000

0.000

40.644

0.000

0.000

851


12

0.000 12 0.000 13 0.000

-153.483 72.892 -153.483 77.150 0.000

40.644

0.000

0.000

40.644

0.000

0.000

Load case 11 (Non-linear): 0.8DL+CW+IPCW Non-linear (Small, Sec, Resid): P- P- 4 Itns, 99.987% Cnv (Res gov)

Y-Axis Memb Node Moment 1 1 0.000 2 0.000 2 2 0.000 3 0.000 3 3 0.000 4 0.000 4 4 0.000 5 0.000 5 5 0.000 6 0.000 6 6 0.000 7 0.000 7 7 0.000 8

852

Axial Z-Axis Force Moment -111.210 -0.001 -113.935 272.886 -113.935 272.885 -116.660 526.758 -71.579 514.769 -71.697 343.477 -71.756 347.913 -71.869 203.508 -71.849 211.094 -72.025 17.416 -72.015 17.423 -72.381 -127.088 -71.867 -127.088 -71.501

Y-Axis

Z-Axis

X-Axis

Shear

Shear

Torsion

77.731

0.000

0.000

71.656

0.000

0.000

71.662

0.000

0.000

65.587

0.000

0.000

-113.084

0.000

0.000

-97.131

0.000

0.000

-97.084

0.000

0.000

-81.016

0.000

0.000

-81.028

0.000

0.000

-50.958

0.000

0.000

-50.973

0.000

0.000

-1.128

0.000

0.000

-8.690

0.000

0.000

32.142

0.000

0.000


0.000 8

8 0.000 9 0.000

9

9 0.000 10 0.000 10 10 0.000 11 0.000 11 11 0.000 12 0.000 12 12 0.000 13 0.000

-50.702 -71.507 -50.708 -71.332 66.786 -71.344 59.254 -71.231 144.881 -71.195 140.473 -71.077 241.074 -70.823 252.982 -68.098 61.589 -68.098 61.588 -65.373 0.000

32.122

0.000

0.000

49.258

0.000

0.000

49.241

0.000

0.000

58.257

0.000

0.000

58.302

0.000

0.000

67.204

0.000

0.000

-67.473

0.000

0.000

-33.048

0.000

0.000

-33.050

0.000

0.000

1.375

0.000

0.000

Load case 12 (Non-linear): 1.25DL+CW+ISCW Non-linear (Small, Sec, Resid): P- P- 4 Itns, 99.995% Cnv (Res gov)

Y-Axis Memb Node Moment 1 1 0.000 2 0.000 2 2 0.000 3 0.000 3 3 0.000 4

Axial Z-Axis Force Moment 13.908 0.000 9.650 86.625 9.650 86.625 5.392 21.162 38.036 27.534 37.852

Y-Axis

Z-Axis

X-Axis

Shear

Shear

Torsion

43.143

0.000

0.000

2.670

0.000

0.000

2.669

0.000

0.000

-37.804

0.000

0.000

3.417

0.000

0.000

3.126

0.000

0.000

853


0.000 4

4 0.000 5 0.000

5

5 0.000 6 0.000

6

6 0.000 7 0.000

7

7 0.000 8 0.000

8

8 0.000 9 0.000

9

9 0.000 10 0.000 10 10 0.000 11 0.000 11 11 0.000 12 0.000 12 12 0.000 13 0.000

33.511 37.854 31.166 37.677 36.738 37.676 32.760 37.402 43.657 37.401 43.658 36.829 42.300 37.439 42.299 38.010 -41.230 38.015 -41.230 38.289 -133.038 38.299 -128.995 38.476 -194.408 38.449 -192.028 38.633 -269.109 53.057 -275.580 57.315 -138.467 57.315 -138.467 61.573 0.000

3.103

0.000

0.000

2.989

0.000

0.000

2.998

0.000

0.000

3.723

0.000

0.000

3.728

0.000

0.000

-7.768

0.000

0.000

-3.883

0.000

0.000

-24.391

0.000

0.000

-24.384

0.000

0.000

-36.594

0.000

0.000

-36.583

0.000

0.000

-43.748

0.000

0.000

-43.771

0.000

0.000

-51.114

0.000

0.000

35.916

0.000

0.000

35.943

0.000

0.000

35.941

0.000

0.000

35.968

0.000

0.000

Load case 13 (Non-linear): 0.8DL+LW1+IPLW Non-linear (Small, Sec, Resid): P- P- 4 Itns, 99.988% Cnv (Res gov)

854


Y-Axis Memb Node Moment 1 1 0.000 2 0.000 2 2 0.000 3 0.000 3 3 0.000 4 0.000 4 4 0.000 5 0.000 5 5 0.000 6 0.000 6 6 0.000 7 0.000 7 7 0.000 8 0.000 8 8 0.000 9 0.000 9 9 0.000 10 0.000 10 10

Axial Z-Axis Force Moment -54.034 0.000 -56.759 90.108 -56.759 90.108 -59.484 251.759 -55.536 242.455 -55.654 156.521 -55.684 159.966 -55.797 86.556 -55.787 92.446 -55.962 -8.640 -55.957 -8.637 -56.323 -81.824 -56.323 -81.824 -55.957 -8.637 -55.962 -8.640 -55.787 92.446 -55.797 86.556 -55.684 159.966 -55.654

Y-Axis

Z-Axis

X-Axis

Shear

Shear

Torsion

14.709

0.000

0.000

33.609

0.000

0.000

33.609

0.000

0.000

52.509

0.000

0.000

-56.667

0.000

0.000

-49.234

0.000

0.000

-49.198

0.000

0.000

-41.651

0.000

0.000

-41.664

0.000

0.000

-27.223

0.000

0.000

-27.235

0.000

0.000

2.950

0.000

0.000

-2.950

0.000

0.000

27.235

0.000

0.000

27.223

0.000

0.000

41.664

0.000

0.000

41.651

0.000

0.000

49.198

0.000

0.000

49.234

0.000

0.000

855


0.000 11 0.000 11 11 0.000 12 0.000 12 12 0.000 13 0.000

156.521 -55.536 242.455 -59.484 251.759 -56.759 90.108 -56.759 90.108 -54.034 0.000

56.667

0.000

0.000

-52.509

0.000

0.000

-33.609

0.000

0.000

-33.609

0.000

0.000

-14.709

0.000

0.000

Load case 14 (Non-linear): 1.25DL+LW2+ISLW Non-linear (Small, Sec, Resid): P- P- 4 Itns, 99.983% Cnv (Res gov)

Y-Axis Memb Node Moment 1 1 0.000 2 0.000 2 2 0.000 3 0.000 3 3 0.000 4 0.000 4 4 0.000 5 0.000 5 5 0.000 6 0.000 6 6

856

Axial Z-Axis Force Moment 86.713 0.000 82.455 -138.160 82.455 -138.160 78.197 -336.781 65.332 -325.836 65.148 -211.544 65.187 -215.576 65.010 -118.343 64.996 -125.205 64.722 10.888 64.715

Y-Axis

Z-Axis

X-Axis

Shear

Shear

Torsion

-28.268

0.000

0.000

-44.806

0.000

0.000

-44.806

0.000

0.000

-61.343

0.000

0.000

74.891

0.000

0.000

64.158

0.000

0.000

64.116

0.000

0.000

53.560

0.000

0.000

53.573

0.000

0.000

35.144

0.000

0.000

35.159

0.000

0.000


0.000 7 0.000 7

7 0.000 8 0.000

8

8 0.000 9 0.000

9

9

0.000 10 0.000 10 10 0.000 11 0.000 11 11 0.000 12 0.000 12 12 0.000 13 0.000

10.882 64.144 114.887 64.144 114.887 64.715 10.882 64.722 10.888 64.996 -125.205 65.010 -118.343 65.187 -215.576 65.148 -211.544 65.332 -325.836 78.197 -336.781 82.455 -138.160 82.455 -138.160 86.713 0.000

-3.363

0.000

0.000

3.363

0.000

0.000

-35.159

0.000

0.000

-35.144

0.000

0.000

-53.573

0.000

0.000

-53.560

0.000

0.000

-64.116

0.000

0.000

-64.158

0.000

0.000

-74.891

0.000

0.000

61.343

0.000

0.000

44.806

0.000

0.000

44.806

0.000

0.000

28.268

0.000

0.000

NODE REACTIONS (kN,kNm) -------------Load case 1 (Linear): Dead load (DL)

X-Axis Y-Axis Y-Axis Z-Axis Node Force Force Moment Moment 1 10.293 25.270 0.000 0.000 13 -10.293 25.270

Z-Axis

X-Axis

Force

Moment

0.000

0.000

0.000

0.000

857


0.000 Load

0.000 0.000

-50.540 0.000 0.000 Reac 0.000 50.540 0.000 0.000

0.000

0.000

0.000

0.000

Equil 4.477E-13 0.000E+00 Resid 4.547E-13 4.405E-13 0.000E+00 4.334E-13

0.000E+00 0.000E+00

0.000E+00

Load case 2 (Linear): Live load including 4.5kN at ridge (LL) X-Axis Y-Axis Y-Axis Z-Axis Node Force Force Moment Moment 1 18.261 30.375 0.000 0.000 13 -18.261 30.375 0.000 0.000

Z-Axis

X-Axis

Force

Moment

0.000

0.000

0.000

0.000

-60.750 0.000 Reac 0.000 60.750 0.000 0.000

0.000

0.000

0.000

0.000


0.000E+00 0.000E+00

0.000E+00

Load

0.000

0.000

Load case 3 (Linear): Cross wind (CW)

X-Axis Y-Axis Y-Axis Z-Axis Node Force Force Moment Moment 1 -70.889 -73.554 0.000 0.000 13 -8.224 -26.461

858

Z-Axis

X-Axis

Force

Moment

0.000

0.000

0.000

0.000


0.000 Load

0.000 79.112

100.014 0.000 3.992 Reac -79.112 -100.014 0.000 0.000

0.000

0.000

0.000

0.000

Equil 0.000E+00 0.000E+00 Resid 4.405E-11 2.018E-12 0.000E+00 3.865E-12

0.000E+00 0.000E+00

0.000E+00

Load case 4 (Linear): Longitudinal wind at first internal frame (LW1) X-Axis Y-Axis Y-Axis Z-Axis Node Force Force Moment Moment 1 -20.355 -63.000 0.000 0.000 13 20.355 -63.000 0.000 0.000 Load 0.000 126.000 0.000 0.000 Reac 0.000 -126.000 0.000 0.000

Z-Axis

X-Axis

Force

Moment

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

Equil -1.478E-12 0.000E+00 Resid 1.364E-12 2.345E-13 0.000E+00 9.948E-13

0.000E+00 0.000E+00

0.000E+00

Load case 5 (Linear): Longitudinal wind with 0.2 external suction (LW2) X-Axis Y-Axis Y-Axis Z-Axis Node Force Force Moment Moment 1 -4.820 -18.000 0.000 0.000 13 4.820 -18.000 0.000 0.000

Z-Axis

X-Axis

Force

Moment

0.000

0.000

0.000

0.000

859


Load

0.000

36.000 0.000 Reac 0.000 -36.000 0.000 0.000

0.000

0.000

0.000

0.000


0.000E+00 0.000E+00

0.000E+00

0.000

Load case 6 (Linear): Cross wind internal pressure (IPCW) X-Axis Y-Axis Y-Axis Z-Axis Node Force Force Moment Moment 1 -15.667 -58.500 0.000 0.000 13 15.667 -58.500 0.000 0.000

Z-Axis

X-Axis

Force

Moment

0.000

0.000

0.000

0.000

117.000 0.000 Reac 0.000 -117.000 0.000 0.000

0.000

0.000

0.000

0.000


0.000E+00 0.000E+00

0.000E+00

Load

0.000

0.000

Load case 7 (Linear): Longitudinal wind internal pressure (IPLW) X-Axis Y-Axis Y-Axis Z-Axis Node Force Force Moment Moment 1 -3.013 -11.250 0.000 0.000 13 3.013 -11.250 0.000 0.000

860

Z-Axis

X-Axis

Force

Moment

0.000

0.000

0.000

0.000


Load

0.000

22.500 0.000 Reac 0.000 -22.500 0.000 0.000

0.000

0.000

0.000

0.000


0.000E+00 0.000E+00

0.000E+00

0.000

Load case 8 (Linear): Lumped masses (DL+LL)

X-Axis Y-Axis Y-Axis Z-Axis Node Force Force Moment Moment 1 3.777 14.005 0.000 0.000 13 -3.777 14.005 0.000 0.000

Z-Axis

X-Axis

Force

Moment

0.000

0.000

0.000

0.000

-28.009 0.000 Reac 0.000 28.009 0.000 0.000

0.000

0.000

0.000

0.000


0.000E+00 0.000E+00

0.000E+00

Load

0.000

0.000

Load case 9 (Spectral) Spectral load case

X-Axis Y-Axis Y-Axis Z-Axis Node Force Force Moment Moment 1 -0.118 -0.239 0.000 0.000 13 -0.118 0.239 0.000 0.000

Z-Axis

X-Axis

Force

Moment

0.000

0.000

0.000

0.000

861


Reac

0.236 0.000

0.000

0.000

0.000

0.000

Load case 10 (Non-linear): 1.25DL+1.5LL Non-linear (Small, Sec, Resid): P- P- 4 Itns, 99.988% Cnv (Res gov) X-Axis Y-Axis Y-Axis Z-Axis Node Force Force Moment Moment 1 40.644 77.150 0.000 0.000 3 0.000 -0.003 0.000 0.000 6 0.000 0.002 0.000 0.004 7 0.000 0.009 0.000 0.000 8 0.000 0.002 0.000 -0.004 11 0.000 -0.003 0.000 0.000 13 -40.644 77.150 0.000 0.000

Z-Axis

X-Axis

Force

Moment

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

-154.300 0.000 Reac 0.000 154.300 0.000 0.000

0.000

0.000

0.000

0.000


0.000E+00 0.000E+00

0.000E+00

Load

0.000

0.000

Load case 11 (Non-linear): 0.8DL+CW+IPCW Non-linear (Small, Sec, Resid): P- P- 4 Itns, 99.987% Cnv (Res gov)

862


X-Axis Y-Axis Y-Axis Z-Axis Node Force Force Moment Moment 1 -77.731 -111.210 0.000 0.001 3 -0.005 0.001 0.000 -0.002 6 0.000 -0.001 0.000 -0.006 7 0.000 -0.015 0.000 -0.001 8 0.000 -0.006 0.000 0.006 11 0.008 0.009 0.000 -0.001 13 -1.375 -65.373 0.000 0.000

Z-Axis

X-Axis

Force

Moment

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

79.112 176.582 0.000 3.990 Reac -79.107 -176.582 0.000 0.000

0.000

0.000

0.000

0.000


0.000E+00 0.000E+00

0.000E+00

Load

Load case 12 (Non-linear): 1.25DL+CW+ISCW Non-linear (Small, Sec, Resid): P- P- 4 Itns, 99.995% Cnv (Res gov) X-Axis Y-Axis Y-Axis Z-Axis Node Force Force Moment Moment 1 -43.143 13.908 0.000 0.000 3 0.003 0.002 0.000 0.000 6 0.000 -0.001

Z-Axis

X-Axis

Force

Moment

0.000

0.000

0.000

0.000

0.000

0.000

863


0.000

-0.001 0.000 -0.001 0.000 0.001 8 0.000 0.001 0.000 0.000 11 -0.003 -0.001 0.000 -0.001 13 -35.968 61.573 0.000 0.000 7

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

79.112 -75.481 0.000 3.994 Reac -79.112 75.481 0.000 0.000

0.000

0.000

0.000

0.000


0.000E+00 0.000E+00

0.000E+00

Load

Load case 13 (Non-linear): 0.8DL+LW1+IPLW Non-linear (Small, Sec, Resid): P- P- 4 Itns, 99.988% Cnv (Res gov) X-Axis Y-Axis Y-Axis Z-Axis Node Force Force Moment Moment 1 -14.709 -54.034 0.000 0.000 3 0.000 0.002 0.000 0.000 6 0.000 -0.002 0.000 -0.003 7 0.000 -0.007 0.000 0.000 8 0.000 -0.002 0.000 0.003 11 0.000 0.002 0.000 0.000 13 14.709 -54.034 0.000 0.000

864

Z-Axis

X-Axis

Force

Moment

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000


Load

0.000

108.068 0.000 Reac 0.000 -108.068 0.000 0.000

0.000

0.000

0.000

0.000


0.000E+00 0.000E+00

0.000E+00

0.000

Load case 14 (Non-linear): 1.25DL+LW2+ISLW Non-linear (Small, Sec, Resid): P- P- 4 Itns, 99.983% Cnv (Res gov) X-Axis Y-Axis Y-Axis Z-Axis Node Force Force Moment Moment 1 28.268 86.713 0.000 0.000 3 0.000 -0.005 0.000 0.000 6 0.000 0.004 0.000 0.006 7 0.000 0.015 0.000 0.000 8 0.000 0.004 0.000 -0.006 11 0.000 -0.005 0.000 0.000 13 -28.268 86.713 0.000 0.000

Z-Axis

X-Axis

Force

Moment

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

-173.425 0.000 Reac 0.000 173.425 0.000 0.000

0.000

0.000

0.000

0.000


0.000E+00 0.000E+00

0.000E+00

Load

0.000

0.000

865


866


Static analysis report (enveloped) This report extract covers the same information as the previous section except that the results are enveloped. It allows you to quickly locate the maximum and minimum values together with their coincident values. Note the summary envelopes at the end of each section which show the overall maximums and minimums for all selected nodes and members. NODE DISPLACEMENTS (mm,rad) ------------------ (*=Maximum, #=Minimum) Envelope = Load Cases 1-9 and All Nodes Load Y-Axis Node Case Rotation 1 2 0.000 3 0.000 2

3 0.000 2 0.000 3 0.000 2 0.000 2 0.000 3 0.000

3

3 0.000 2 0.000

X-Axis Z-Axis Transl'n Rotation 0.000 0.002* 0.000 -0.018# 63.213* -0.014 -6.194# 0.001 63.213 -0.014 -6.194 0.001 -6.194 0.001* 63.213 -0.014# 99.246* -0.004 -3.698# -0.003

Y-Axis

Z-Axis

X-Axis

Transl'n

Transl'n

Rotation

0.000

0.000

0.000

0.000

0.000

0.000

0.117

0.000

0.000

-0.048

0.000

0.000

0.117*

0.000

0.000

-0.048#

0.000

0.000

-0.048

0.000

0.000

0.117

0.000

0.000

0.234

0.000

0.000

-0.097

0.000

0.000

867


3 0.000 2 0.000 4 0.000 3 0.000 4

3 0.000 2 0.000 4 0.000 2 0.000 4 0.000 2 0.000

5

3 0.000 2 0.000 4 0.000 2 0.000 4 0.000 2 0.000

6

3 0.000 2 0.000 4 0.000 2

868

99.246 -0.004 -3.698 -0.003 6.504 0.005* 99.246 -0.004#

0.234*

0.000

0.000

-0.097#

0.000

0.000

0.200

0.000

0.000

0.234

0.000

0.000

98.835* -0.001 -3.193# -0.004 5.584 0.007 -3.193 -0.004 5.584 0.007* -3.193 -0.004#

-3.476

0.000

0.000

-5.540

0.000

0.000

9.951*

0.000

0.000

-5.540#

0.000

0.000

9.951

0.000

0.000

-5.540

0.000

0.000

98.245* 0.004 -2.629# -0.006 4.560 0.010 -2.629 -0.006 4.560 0.010* -2.629 -0.006#

-0.524

0.000

0.000

-13.435

0.000

0.000

24.370*

0.000

0.000

-13.435#

0.000

0.000

24.370

0.000

0.000

-13.435

0.000

0.000

27.786

0.000

0.000

-35.183

0.000

0.000

64.155*

0.000

0.000

-35.183#

0.000

0.000

96.822* 0.013 -1.532# -0.008 2.597 0.015 -1.532


0.000 4 0.000 2 0.000 7

3 0.000 4 0.000 4 0.000 2 0.000 3 0.000 2 0.000

8

3 0.000 4 0.000 3 0.000 2 0.000 2 0.000 4 0.000

9

3 0.000 4 0.000 3 0.000 2 0.000 2 0.000

-0.008 2.597 0.015* -1.532 -0.008# 93.373* 0.005 0.000# 0.000 0.000 0.000 0.000 0.000 93.373 0.005* 0.000 0.000# 92.581* -0.010 -2.597# -0.015 92.581 -0.010 1.532 0.008 1.532 0.008* -2.597 -0.015# 90.748* -0.013 -4.560# -0.010 90.748 -0.013 2.629 0.006 2.629 0.006*

64.155

0.000

0.000

-35.183

0.000

0.000

96.251

0.000

0.000

118.858

0.000

0.000

118.858*

0.000

0.000

-66.190#

0.000

0.000

96.251

0.000

0.000

-66.190

0.000

0.000

78.638

0.000

0.000

64.155

0.000

0.000

78.638*

0.000

0.000

-35.183#

0.000

0.000

-35.183

0.000

0.000

64.155

0.000

0.000

42.540

0.000

0.000

24.370

0.000

0.000

42.540*

0.000

0.000

-13.435#

0.000

0.000

-13.435

0.000

0.000

869


3

90.748 -0.013#

42.540

0.000

0.000

3

89.618* -0.013 -5.584# -0.007 89.618 -0.013 3.193 0.004 3.193 0.004* 89.618 -0.013#

21.016

0.000

0.000

9.951

0.000

0.000

21.016*

0.000

0.000

-5.540#

0.000

0.000

-5.540

0.000

0.000

21.016

0.000

0.000

88.460* -0.013 -6.504# -0.005 -6.504 -0.005 3.698 0.003 3.698 0.003* 88.460 -0.013#

0.084

0.000

0.000

0.200

0.000

0.000

0.200*

0.000

0.000

-0.097#

0.000

0.000

-0.097

0.000

0.000

0.084

0.000

0.000

0.042

0.000

0.000

0.100

0.000

0.000

0.100*

0.000

0.000

-0.048#

0.000

0.000

0.100

0.000

0.000

0.042

0.000

0.000

0.000 10 0.000 4 0.000 3 0.000 2 0.000 2 0.000 3 0.000 11

3 0.000 4 0.000 4 0.000 2 0.000 2 0.000 3 0.000

12

3 0.000 4 0.000 4 0.000 2 0.000 4 0.000 3 0.000

870

43.844* -0.012 -10.251# 0.002 -10.251 0.002 6.194 -0.001 -10.251 0.002* 43.844 -0.012#


13

4 0.000 3 0.000

3

3 0.000

12

4 0.000

7

4 0.000

7

2 0.000

6

4 0.000

1

3 0.000

0.000 0.003* 0.000 -0.012#

0.000

0.000

0.000

0.000

0.000

0.000

99.246* -0.004 -10.251# 0.002 0.000 0.000 0.000 0.000 2.597 0.015* 0.000 -0.018#

0.234

0.000

0.000

0.100

0.000

0.000

118.858*

0.000

0.000

-66.190#

0.000

0.000

64.155

0.000

0.000

0.000

0.000

0.000

MEMBER FORCES AND MOMENTS (kN,kNm) ------------------------- (*=Maximum, #=Minimum) Envelope = Load Cases 10-14 and All Members and All Sections The following maximums and minimums are taken from either end of the member Load Y-Axis Memb Case Moment 1

14 0.000 11 0.000 11 0.000 14 0.000

Axial Z-Axis Force Moment 86.713* 0.000 -113.935# 272.886 -111.210 -0.001 82.455 -138.160

Y-Axis

Z-Axis

X-Axis

Shear

Shear

Torsion

-28.268

0.000

0.000

71.656

0.000

0.000

77.731*

0.000

0.000

-44.806#

0.000

0.000

871


2

3

4

872

11 0.000 10 0.000

-113.935 272.886* 72.892 -153.483#

71.656

0.000

0.000

-40.644

0.000

0.000

14 0.000 11 0.000 11 0.000 14 0.000 11 0.000 14 0.000

82.455* -138.160 -116.660# 526.758 -113.935 272.885 78.197 -336.781 -116.660 526.758* 78.197 -336.781#

-44.806

0.000

0.000

65.587

0.000

0.000

71.662*

0.000

0.000

-61.343#

0.000

0.000

65.587

0.000

0.000

-61.343

0.000

0.000

14 0.000 11 0.000 14 0.000 11 0.000 11 0.000 14 0.000

65.332* -325.836 -71.697# 343.477 65.332 -325.836 -71.579 514.769 -71.579 514.769* 65.332 -325.836#

74.891

0.000

0.000

-97.131

0.000

0.000

74.891*

0.000

0.000

-113.084#

0.000

0.000

-113.084

0.000

0.000

74.891

0.000

0.000

14 0.000 11 0.000 14 0.000 11 0.000 11 0.000 14

65.187* -215.576 -71.869# 203.508 65.187 -215.576 -71.756 347.913 -71.756 347.913* 65.187

64.116

0.000

0.000

-81.016

0.000

0.000

64.116*

0.000

0.000

-97.084#

0.000

0.000

-97.084

0.000

0.000

64.116

0.000

0.000


5

6

7

8

0.000

-215.576#

14 0.000 11 0.000 14 0.000 11 0.000 11 0.000 14 0.000

64.996* -125.205 -72.025# 17.416 64.996 -125.205 -71.849 211.094 -71.849 211.094* 64.996 -125.205#

14 0.000 11 0.000 14 0.000 11 0.000 10 0.000 11 0.000

64.715* 10.882 -72.381# -127.088 64.715 10.882 -72.015 17.423 40.765 118.633* -72.381 -127.088#

14 0.000 11 0.000 11 0.000 14 0.000 10 0.000 11 0.000 14

53.573

0.000

0.000

-50.958

0.000

0.000

53.573*

0.000

0.000

-81.028#

0.000

0.000

-81.028

0.000

0.000

53.573

0.000

0.000

35.159

0.000

0.000

-1.128

0.000

0.000

35.159*

0.000

0.000

-50.973#

0.000

0.000

1.242

0.000

0.000

-1.128

0.000

0.000

64.715* 10.882 -71.867# -127.088 -71.501 -50.702 64.715 10.882 40.765 118.633* -71.867 -127.088#

-35.159

0.000

0.000

-8.690

0.000

0.000

32.142*

0.000

0.000

-35.159#

0.000

0.000

-1.242

0.000

0.000

-8.690

0.000

0.000

64.996*

-53.573

0.000

0.000

873


9

10

11

874

0.000 11 0.000 11 0.000 14 0.000 13 0.000 12 0.000

-125.205 -71.507# -50.708 -71.332 66.786 64.996 -125.205 -55.787 92.446* 38.289 -133.038#

14 0.000 11 0.000 11 0.000 14 0.000 13 0.000 14 0.000

32.122

0.000

0.000

49.258*

0.000

0.000

-53.573#

0.000

0.000

41.664

0.000

0.000

-36.594

0.000

0.000

65.187* -215.576 -71.344# 59.254 -71.231 144.881 65.187 -215.576 -55.684 159.966* 65.187 -215.576#

-64.116

0.000

0.000

49.241

0.000

0.000

58.257*

0.000

0.000

-64.116#

0.000

0.000

49.198

0.000

0.000

-64.116

0.000

0.000

14 0.000 11 0.000 11 0.000 14 0.000 13 0.000 14 0.000

65.332* -325.836 -71.195# 140.473 -71.077 241.074 65.332 -325.836 -55.536 242.455* 65.332 -325.836#

-74.891

0.000

0.000

58.302

0.000

0.000

67.204*

0.000

0.000

-74.891#

0.000

0.000

56.667

0.000

0.000

-74.891

0.000

0.000

14 0.000 11 0.000

82.455* -138.160 -70.823# 252.982

44.806

0.000

0.000

-67.473

0.000

0.000


14 0.000 11 0.000 11 0.000 14 0.000

78.197 -336.781 -70.823 252.982 -70.823 252.982* 78.197 -336.781#

14 0.000 11 0.000 14 0.000 13 0.000 13 0.000 10 0.000

86.713* 0.000 -68.098# 61.588 82.455 -138.160 -56.759 90.108 -56.759 90.108* 72.892 -153.483#

14 0.000 2 11 0.000 1 11 0.000 3 11 0.000 2 11 0.000 2 14 0.000

86.713* 0.000 -116.660# 526.758 -111.210 -0.001 -71.579 514.769 -116.660 526.758* 78.197 -336.781#

12

1

61.343*

0.000

0.000

-67.473#

0.000

0.000

-67.473

0.000

0.000

61.343

0.000

0.000

28.268

0.000

0.000

-33.050

0.000

0.000

44.806*

0.000

0.000

-33.609#

0.000

0.000

-33.609

0.000

0.000

40.644

0.000

0.000

-28.268

0.000

0.000

65.587

0.000

0.000

77.731*

0.000

0.000

-113.084#

0.000

0.000

65.587

0.000

0.000

-61.343

0.000

0.000

NODE REACTIONS (kN,kNm) -------------- (*=Maximum, #=Minimum) Envelope = Load Cases 1-9 and All Nodes

875


Load Y-Axis Node Case Moment 1 2 0.000 3 0.000 2 0.000 3 0.000 3 0.000 4 0.000 3

5 0.000 3 0.000 6 0.000 3 0.000 2 0.000 3 0.000

6

2 0.000 3 0.000 3 0.000 4 0.000 1 0.000 6 0.000

876

X-Axis Z-Axis Force Moment 18.261* 0.000 -70.889# 0.000 18.261 0.000 -70.889 0.000 -70.889 0.000* -20.355 0.000#

Y-Axis

Z-Axis

X-Axis

Force

Force

Moment

30.375

0.000

0.000

-73.554

0.000

0.000

30.375*

0.000

0.000

-73.554#

0.000

0.000

-73.554

0.000

0.000

-63.000

0.000

0.000

0.000* 0.000 0.000# 0.000 0.000 0.000 0.000 0.000 0.000 0.000* 0.000 0.000#

0.000

0.000

0.000

0.000

0.000

0.000

0.000*

0.000

0.000

0.000#

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000* 0.000 0.000# 0.000 0.000 0.000 0.000 0.000 0.000 0.000* 0.000 0.000#

0.000

0.000

0.000

0.000

0.000

0.000

0.000*

0.000

0.000

0.000#

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000


7

3 0.000 4 0.000 2 0.000 3 0.000 6 0.000 3 0.000

8

2 0.000 3 0.000 4 0.000 2 0.000 2 0.000 4 0.000

11

2 0.000 3 0.000 6 0.000 4 0.000 4 0.000 3 0.000

13

4 0.000

0.000* 0.000 0.000# 0.000 0.000 0.000 0.000 0.000 0.000 0.000* 0.000 0.000#

0.000

0.000

0.000

0.000

0.000

0.000

0.000*

0.000

0.000

0.000#

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000* 0.000 0.000# 0.000 0.000 0.000 0.000 0.000 0.000 0.000* 0.000 0.000#

0.000

0.000

0.000

0.000

0.000

0.000

0.000*

0.000

0.000

0.000#

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000* 0.000 0.000# 0.000 0.000 0.000 0.000 0.000 0.000 0.000* 0.000 0.000#

0.000

0.000

0.000

0.000

0.000

0.000

0.000*

0.000

0.000

0.000#

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

20.355* 0.000

-63.000

0.000

0.000

877


2 0.000 2 0.000 4 0.000 4 0.000 3 0.000 13

4 0.000

1

3 0.000

1

2 0.000

1

3 0.000

11

4 0.000

3

3 0.000

-18.261# 0.000 -18.261 0.000 20.355 0.000 20.355 0.000* -8.224 0.000# 20.355* 0.000 -70.889# 0.000 18.261 0.000 -70.889 0.000 0.000 0.000* 0.000 0.000#

30.375

0.000

0.000

30.375*

0.000

0.000

-63.000#

0.000

0.000

-63.000

0.000

0.000

-26.461

0.000

0.000

-63.000

0.000

0.000

-73.554

0.000

0.000

30.375*

0.000

0.000

-73.554#

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

Y-Axis

Z-Axis

X-Axis

Force

Force

Moment

77.150

0.000

0.000

-111.210

0.000

0.000

86.713*

0.000

0.000

-111.210#

0.000

0.000

NODE REACTIONS (kN,kNm) -------------- (*=Maximum, #=Minimum) Envelope = Load Cases 10-14 and All Nodes Load Y-Axis Node Case Moment 1 10 0.000 11 0.000 14 0.000 11

878

X-Axis Z-Axis Force Moment 40.644* 0.000 -77.731# 0.001 28.268 0.000 -77.731


3

6

7

0.000 11 0.000 12 0.000

0.001 -77.731 0.001* -43.143 0.000#

12 0.000 11 0.000 13 0.000 14 0.000 12 0.000 11 0.000

0.003* 0.000 -0.005# -0.002 0.000 0.000 0.000 0.000 0.003 0.000* -0.005 -0.002#

13 0.000 14 0.000 14 0.000 13 0.000 14 0.000 11 0.000 11 0.000 12 0.000 14 0.000 11 0.000 12 0.000

-111.210

0.000

0.000

13.908

0.000

0.000

0.002

0.000

0.000

0.001

0.000

0.000

0.002*

0.000

0.000

-0.005#

0.000

0.000

0.002

0.000

0.000

0.001

0.000

0.000

0.000* -0.003 0.000# 0.006 0.000 0.006 0.000 -0.003 0.000 0.006* 0.000 -0.006#

-0.002

0.000

0.000

0.004

0.000

0.000

0.004*

0.000

0.000

-0.002#

0.000

0.000

0.004

0.000

0.000

-0.001

0.000

0.000

0.000* -0.001 0.000# 0.001 0.000 0.000 0.000 -0.001 0.000 0.001*

-0.015

0.000

0.000

-0.001

0.000

0.000

0.015*

0.000

0.000

-0.015#

0.000

0.000

-0.001

0.000

0.000

879


8

11

13

880

11 0.000

0.000 -0.001#

14 0.000 11 0.000 14 0.000 11 0.000 11 0.000 14 0.000

0.000* -0.006 0.000# 0.006 0.000 -0.006 0.000 0.006 0.000 0.006* 0.000 -0.006#

11 0.000 12 0.000 11 0.000 14 0.000 14 0.000 11 0.000

0.008* -0.001 -0.003# -0.001 0.008 -0.001 0.000 0.000 0.000 0.000* 0.008 -0.001#

13 0.000 10 0.000 14 0.000 11 0.000 12 0.000 13 0.000

14.709* 0.000 -40.644# 0.000 -28.268 0.000 -1.375 0.000 -35.968 0.000* 14.709 0.000#

-0.015

0.000

0.000

0.004

0.000

0.000

-0.006

0.000

0.000

0.004*

0.000

0.000

-0.006#

0.000

0.000

-0.006

0.000

0.000

0.004

0.000

0.000

0.009

0.000

0.000

-0.001

0.000

0.000

0.009*

0.000

0.000

-0.005#

0.000

0.000

-0.005

0.000

0.000

0.009

0.000

0.000

-54.034

0.000

0.000

77.150

0.000

0.000

86.713*

0.000

0.000

-65.373#

0.000

0.000

61.573

0.000

0.000

-54.034

0.000

0.000


1

10 0.000 1 11 0.000 1 14 0.000 1 11 0.000 8 11 0.000 8 14 0.000

40.644* 0.000 -77.731# 0.001 28.268 0.000 -77.731 0.001 0.000 0.006* 0.000 -0.006#

77.150

0.000

0.000

-111.210

0.000

0.000

86.713*

0.000

0.000

-111.210#

0.000

0.000

-0.006

0.000

0.000

0.004

0.000

0.000

881


Bill of materials report This report extract shows the bill of materials listing that can be produced by SPACE GASS. BILL OF MATERIALS (m,m^2,kg) ----------------Unit Total Memb Sect Length 1 1 15.000 2 3 3.264 3 4 3.265 4 2 5.988 5 2 12.517

Unit Total Qty Section Name Mass Mass 4 530 UB 92.4 347.362 1389.450 2 360 UB 50.7-A 138.961 277.922 2 360 UB 50.7-B 124.458 248.916 2 360 UB 50.7 152.070 304.140 2 360 UB 50.7 317.869 635.737

Total mass = 2856.165 Centre of gravity = 12.500,5.802,0.000

882

Length 3.750 1.632 1.632 2.994 6.259


Dynamic frequency analysis report This report extract shows the natural frequencies and periods for each of the dynamic modes within each mass load case. In this case there was only one mass load case which we analysed for three dynamic modes. DYNAMIC NATURAL FREQUENCIES (Hz,Sec) --------------------------Mass Case Mode Iterations 8 1 11 2 13 3 14 4 14 5 16 6 14

Natural Frequency

Natural Period

Frequency Tolerance

0.862

1.160

0.000977

1.823

0.548

0.000842

4.879

0.205

0.000890

6.275

0.159

0.000596

6.277

0.159

0.000192

6.757

0.148

0.000766

883


Dynamic response analysis report This report extract shows the general results of a dynamic response spectrum analysis for spectral load case 9. A dynamic response analysis also calculates displacements, forces, moments and reactions just like a static analysis and, for comparison purposes, they are included with the static analysis results in this report. DYNAMIC RESPONSE SPECTRUM (kN,kg,sec,Hz) ------------------------Spectral case 9: Spectral load case Mass load case: Direction vector: 0.000 Loading code: Auto scaling of base shear: Sign of the results: Probability factor: Hazard factor: Structural ductility factor: Structural perf. factor Spectral curve multiplier: Mode combination method: Squares)

Base Direction Shear X-Axis 0.218% Y-Axis 0.000% Z-Axis 0.000%

AS1170.4-2007 Off Mode shape 1 (Calculated) 1.000 0.080 2.000 0.770 0.0308 SRSS (Square Root of the Sum of

Dominant

Total Static

Total

MPF for Dominant

Total Mass Part

Mode

Force

Mass

Mode

Factor

1

0.0864 10998.8020

92.652%

98.894%

2

0.5035 10998.8020

59.179%

59.179%

1

0.0097

1234.6723

0.000%

0.000%

Damping

Natural

Natural

Mode

884

8 Dx = 1.000, Dy = 0.000, Dz =


Mass Part Direction Shape Factor Vector 1 92.652% Vector 2 0.000% Vector 3 6.241%

Spectral Curve

Factor

Period

Frequency

NEWCASTLE 5%

5.0%

1.1603

0.862

NEWCASTLE 5%

5.0%

0.5484

1.823

NEWCASTLE 5%

5.0%

0.2049

4.879 Total

98.894%

885


Buckling analysis report This report extract shows the buckling load factors and the member effective lengths for each combination load case. The primary load cases were not included in the buckling analysis because in real life they could not occur in isolation. Note that member effective lengths are not calculated for load cases 11 and 13 because their buckling load factors are greater than 1000 (beyond the upper limit specified at the start of the analysis). BUCKLING LOAD FACTORS --------------------Load Node at Case Mode Max Rotn 10 1 13 (X) 11 1 12 1 7 (Y) 13 1 14 1 7 (Y)

Load

Node at

Factor

Tolerance Iterations Max Trans

11.137

0.007812

15

12 (Z)

>1000.0 13.848

0.007812

15

9 (Z)

>1000.0 8.199

0.007812

15

9 (Z)

BUCKLING EFFECTIVE LENGTHS (kN,m) -------------------------Load case 10 (Linear): 1.25DL+1.5LL Mode 1

886

Memb 1 2 3 4 5 6 7 8 9

Pcr 859.200 811.779 487.541 482.688 477.352 468.334 468.334 477.352 482.688

Length 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

Ly 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

Lz 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000


10 11 12

487.541 811.779 859.200

0.000 0.000 0.000

0.000 0.000 0.000

0.000 0.000 0.000

Ly 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

Lz 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

Ly 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

Lz 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

Load case 12 (Linear): 1.25DL+CW+ISCW

Mode 1

Memb 1 2 3 4 5 6 7 8 9 10 11 12

Pcr 196.552 137.588 529.091 526.567 524.103 520.293 528.319 532.181 534.761 536.945 789.717 848.681

Length 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

Load case 14 (Linear): 1.25DL+LW2+ISLW

Mode 1

Memb 1 2 3 4 5 6 7 8 9 10 11 12

Pcr 710.976 676.063 530.441 529.252 527.689 525.385 525.385 527.689 529.252 530.441 676.063 710.976

Length 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

887

Portal Frame Member Design Portal frame member design This worked example considers the AS4100 member design of the 25m span haunched portal frame which was analysed in the previous appendix. The design is based on the non-linear analysis results of the combination load cases 10 - 14. This appendix considers only the design of the portal frame members. The portal frame analysis and connection design is covered in Portal frame analysis and Portal frame connection design. This example bases the member design directly on the forces and moments obtained from the non-linear analysis. The non-linear analysis results for combination load cases 10 - 14 are included in the static analysis report (itemised) of the portal frame analysis worked example. The portal frame has wall girts spaced at 1200mm and 1700mm, and roof purlins spaced at 1000mm, 1200mm and 800mm as shown in the following drawing. The frame is fully symmetrical about its centre.

889


In order to check deflections, the following maximum limits will be used. Eaves sway limit for serviceability: h/150 Apex sag limit for dead load: L/360

890

Portal Frame Member Design Apex sag limit for live load: L/240 Apex deflection limit for: L/150 serviceability: Eaves sway due to cross wind: 99*(38/60)**2= 40mm = h/188 (Ok). (Vu = 60m/s, Vs = 38m/s) Apex sag due to dead load: 36mm = L/694 (Ok). Apex sag due to live load: 66mm = L/379 (Ok). Apex uplift due to cross wind (96+109)*(38/60)**2 = 82mm = L/305 (Ok). and internal pressure: In order to define the steel member design data for the frame, the following design groups were specified. Group 1: Left column Members 1 and 2 Group 2: Left rafter Members 3, 4, 5 and 6 Group 3: Right rafter Members 7, 8, 9 and 10 Group 4: Right column Members 11 and 12 (Haunches have to be checked by hand) Groups 3 and 4 were specified as members 10,9,8,7 and 12,11 (rather than 7,8,9,10 and 11,12) so that the positions and types of flange restraints could be referenced from the column base and the narrow end of the haunch in similar fashion to groups 1 and 2. This was not absolutely necessary, however it made the input of the restraint data for groups 3 and 4 identical to the data for groups 1 and 2.

In the diagram above, the thick grey lines show the four design groups. They are drawn short of their ends so that you can easily see where they start and finish.

891

SPACE GASS 12 User Manual Even though the haunches can’t be design or checked (because of their varying properties and non-standard shape), they have been included in the rafter groups 2 and 3. They have, however, been excluded from the portion of the rafter being designed or checked by using an I (ignore) zone in the flange restraint data. If the haunch members had simply been omitted from the rafter groups then the group lengths would have been shorter and the compression and bending effective lengths could have been underestimated. All compression effective lengths were calculated by the buckling analysis and automatically transferred into the member design. The advantage of doing it this way is that different effective lengths can be used for each design load case. The alternative is to manually input the effective lengths, however they are then used for every design load case and the design is usually not as efficient. The minor axis (out-of-plane) compression effective lengths were also specified as being braced at each end due to wall and roof bracing that prevents any out-ofplane buckling at the rafter ends. This has the effect of limiting the minor axis compression effective lengths to no longer than the rafter group length. Flange restraints for the columns were placed on the outside (top) flange at each end and at each girt location. Inside (bottom) flange restraints were placed at the column ends. There are no column fly braces and therefore no intermediate inside flange restraints were applied. For each column, the column base plate was assumed to provide full restraint to both column flanges and hence restraint codes of F (full) were specified for both column flanges at the base. Because wall bracing and an eaves strut effectively prevented lateral deflection of both flanges at the top of the column and because the rafter provided partial (or full) twist restraint, the restraints applied to the top of the column were assumed to be F (full). In addition, the stiffness of the haunch meant that the restraining effect of the rafter could be considered to be applied at the bottom of the haunch, hence additional flange restraints identical to those at the top of the column were applied to both column flanges at the base of the haunch. An I (ignore) continuous restraint was also applied to the segment from the bottom of the haunch to the top of the column so that it would be ignored during the design. Top flange restraints of L (lateral) were positioned at each purlin location in the rafter design groups, except that the purlins close to the end of the haunch and near

892

Portal Frame Member Design the apex were conservatively assumed to be at the ends of the haunch and at the apex. Bottom flange restraints were also positioned at the ends of the haunch and at midspan of the rafter design groups to coincide with fly braces at those locations. Restraint codes of I (ignore) were positioned between the first two rafter flange restraints so that the haunches could be excluded from the calculations. Fly braces were located at the face of the columns and at the apex, and hence the top and bottom flange restraints at the ends of the rafter design groups were assumed to be at least F (full).

The above diagram shows the location and type of all the flange restraints. Note that the effect of the fly brace at midspan could also have been taken into account by specifying a full restraint at the fly brace location on the top flange and not specifying anything on the bottom flange. A full or partial restraint on one flange causes SPACE GASS to automatically place a partial restraint (at least) on the other flange (see also Effective flange restraints). This method would, however increase the kt factor marginally. All of the member design data was input graphically, however it could have been input just as successfully via a datasheet or by importing it from a text data file. For information about the graphical input procedure for steel member design data, see also Steel member input methods. For detailed information about the actual member design data values and settings, see also Steel member design data.

893


Member design results The AS4100 member design module running in checking mode was then initiated and the results are shown in the following computer printout. The rafters are satisfactory with load factors of 1.15 and 1.05. The 530 UB 92.4 columns have also passed with load factors of 1.28 on both sides.

The results of a steel member design or check can be shown graphically as in the above diagram. The member colors matched to the legend show that the columns and left rafter have passed with load factors greater than 1.10, while the right rafter has passed with a load factor greater than 1.00. In this example, because the approximate sizes of the columns and rafters were known in advance, it was appropriate to simply run a steel member check rather than a design. If the steel module had been run in design mode instead, the column members may have been selected as slightly less than 530 UB 92.4 because of their load factors being 1.28 and quite a bit greater than 1.00. Thus, if you know that your initial analysis member sizes are close to the final design sizes, the recommended procedure is to run a steel member check first rather than a design. If the check results show that the analysis member sizes are almost correct then it is a simple matter to manually change some of the analysis member sizes and then do a final check to verify that they are correct. Alternatively, if your analysis member sizes have not been chosen carefully, you should run a steel member design and then choose "Update analysis member sizes" from the Steel menu (see also Updating analysis member sizes) to update the

894

Portal Frame Member Design analysis data and bring it in line with the design data. You should then iterate the analysis-design procedure until the design member sizes agree with the analysis member sizes.

895


Steel member design report AS4100 1998 STEEL MEMBER SYMBOLS NOTATION -----------------------------------------

This report extract shows all of the steel member design input and output data. Group Segment Load factor

= An actual member in the real structure which consists of one or more analysis members joined together end-to-end. = A part of the total member length under consideration (usually equals the portion between lateral restraints). = The ratio of the minimum loads which cause failure to the actual design loads. = Grade of steel. = Yield stress of overall section. = Yield stress of web. = Ultimate tensile strength. = Total group length. = Length of the critical segment in the group. = Twist restraint effective length factor. = Load height effective length factor. = Lateral rotation effective length factor. = Bending effective length for major axis bending. = Compression effective length for major axis buckling. = Compression effective length for minor axis buckling. = Torsion effective length. = Slenderness ratio for compression or bending. = Area of bolt holes removed from flanges. = Area of bolt holes removed from web. = Net area of section. (Gross area less Arf and Arw). = Effective area of section. = Form factor for compression members. = Correction factor for eccentric effects in tension

Grade Fy Fyw Fu Ltot Lseg kt (5.6.3) kl (5.6.3) kr (5.6.3) Le (5.6.3) Lx (6.3.2) Ly (6.3.2) Lz L/r Arf Arw An Ae (6.2.2) Kf (6.2.2) Kt (7.3) members. m (5.6.1.1) = Moment modification factor for bending. s (5.6.1.1) = Bending member slenderness reduction factor. cx (6.3.3) = Compression member slenderness reduction factor (major). cy (6.3.3) = Compression member slenderness reduction factor (minor). b (6.3.3) = Compression member section constant. me (8.4.4.1) = Ratio of major axis moments at ends of segment. mx (8.4.2.2) = Ratio of major axis moments at ends of member. my (8.4.2.2) = Ratio of minor axis moments at ends of segment.  (8.3.4) = Index.  (3.4) = Capacity factor. N* = Design axial force (+ve=compression). Vx* = Design major axis shear force (not considered). Vy* = Design minor axis shear force. Mx* = Design major axis bending moment. My* = Design minor axis bending moment. Nt (7.2) = Section capacity in tension. Ns (6.2) = Section capacity in compression. Ncx (6.3.3) = Major axis member capacity in compression. Ncy (6.3.3) = Minor axis member capacity in compression. Vv (5.11) = Shear capacity of web. Mf (5.12.2) = Moment capacity of flanges. Msx (5.2) = Section major axis moment capacity. Msy (5.2) = Section minor axis moment capacity. Mbx (5.6) = Member major axis moment capacity. Mox (8.4.4) = Member out-of-plane major axis moment capacity. Mrx (8.3.2) = Section major axis moment capacity reduced by axial force. Mry (8.3.3) = Section minor axis moment capacity reduced by axial force. Mix (8.4.2.2) = Member in-plane major axis moment capacity. Miy (8.4.2.2) = Member in-plane minor axis moment capacity. Mtx (8.4.5.2) = Lesser of Mrx and Mox. Mcx (8.4.5.1) = Lesser of Mix and Mox.

STEEL MEMBER DESIGN DATA (m) -----------------------Restraint codes are: F => Fixed restraint P => Partial restraint R => Fixed and rotational restraint S => Partial and rotational restraint L => Lateral restraint U => Unrestrained 896 C => Continuous lateral restraint I => Ignore segment Group: 1 Left column Member list: 1,2

Portal Frame Connection Design Portal frame connection design This worked example considers the AS4100 connection design of the 25m span haunched portal frame which was analysed in a previous appendix. The design is based on the non-linear analysis results of the combination load cases 10 - 14. This appendix considers only the design of the portal frame connections. The portal frame analysis and member design is covered in Portal frame analysis and Portal frame member design. This example bases the member design directly on the forces and moments obtained from the non-linear analysis. The non-linear analysis results for combination load cases 10 - 14 are included in the static analysis report (itemised) of the portal frame analysis worked example. The portal frame has wall girts spaced at 1200mm and 1700mm, and roof purlins spaced at 1000mm, 1200mm and 800mm as shown in the following drawing. The frame is fully symmetrical about its centre.

897


898


Connection design results The summary results of the steel connections design are as follows. More detailed reports can also be produced.

Left Baseplate

899


Left Knee

Ridge

900


Right Knee

901


Right Baseplate

STEEL CONNECTION DESIGN DATA ---------------------------CONNECTION 1 - LEFT BASEPLATE ----------------------------Member:

Strength Grade:

Normal

Dimensions (LxWxT): 575x250x20 mm Plate Strength Grade: Normal Full Contact: YES

Fy:

350 MPa

Welds: Weld Strength Grade:

6 mm Normal

Weld Category: Weld Inside Flange:

SP NO

Bolts: Bolt Threads: Bolts: Pitch: Prying Factor:

M24 Include 4 360 mm 0.71

Bolt Procedure: Bolt Strength Grade: Embedded Length: Gauge:

Snug Normal 195 mm 140 mm

Concrete: Concrete:

CONCRETE-20

Type:

Rectangular

902

1

Portal Frame Connection Design Dimensions (LxWxD):

775x450x395 mm

Grout: Thickness:

20 mm

Fc:

25 MPa

Strength Grade: Strength Grade:

Normal Normal

CONNECTION 3 - LEFT KNEE -----------------------Connection Type:

Bolted End Plate

Supporting Member: Supported Member:

2 3

Haunch (D/Bb/Tb/Tw): Haunch Length:

333.1/171/11.5/7.3 mm 3000 mm Use Stitch Bolt:

NO

Stiffen web if necessary Stiffen flange if necessary Dimensions (LxWxT): 885x195x25 mm Plate Strength Grade: Normal Flange Weld Type:

Butt

Web Weld Type:

Butt

End Plate Stiffened:

NO

Bolts: Bolt Threads: Top Bolts (out/in): Pitch outside: Gauge: Dist to Flange out: Bolt Head Side:

M20 Include 2/4 0 mm 120 mm 65 mm Default

Top Web Stiffener: Dimensions (WxT): 84x12 mm Plate Length: Full Plate Strength Grade: Normal Welds: Weld Strength Grade: Weld Length:

8 mm Normal Full

Bottom Web Stiffener: Dimensions (WxT): 84x12 mm Plate Length: Full Plate Strength Grade: Normal Welds: Weld Strength Grade:

8 mm Normal

Fy:

250 MPa

Bolt Procedure: Bolt Strength Grade: Bot Bolts (out/in): Pitch inside: Vert Edge Dist: Dist to Flange in:

Bearing High 2/4 80 mm 30 mm 65 mm

Length: Fy:

0 mm 260 MPa

Weld Category:

GP

Length:

0 mm

Length: Fy:

0 mm 260 MPa

Weld Category:

GP

903

SPACE GASS 12 User Manual Weld Length:

Full

Length:

0 mm

Fy:

250 MPa

8 mm Normal

Weld Category:

GP

6 7


Normal Normal

Fy:

250 MPa

Web Welds: Weld Strength Grade:

6 mm Normal




Normal Normal

Flange Doubler: Position: Both Dimensions (LxWxT): 361.52x70x16 mm Plate Strength Grade: Normal Welds: Weld Strength Grade: CONNECTION 7 - RIDGE -------------------Supported Member 1: Supported Member 2:

Dimensions (LxWxT): 550x200x25 mm Plate Strength Grade: Normal Flange Weld Type:

Butt

Web Weld Type: Weld Category:

Fillet SP


NO



CONNECTION 11 - RIGHT KNEE -------------------------Connection Type:

Bolted End Plate

Supporting Member: Supported Member:

11 10

Haunch (D/Bb/Tb/Tw): Haunch Length:

333.1/171/11.5/7.3 mm 3000 mm Use Stitch Bolt:

NO

Stiffen web if necessary Stiffen flange if necessary Dimensions (LxWxT): 885x195x25 mm Plate Strength Grade: Normal Flange Weld Type:

904

Butt

Fy:

250 MPa


Web Weld Type: Weld Category:

Fillet SP

Web Welds: Weld Strength Grade:

6 mm Normal


NO





Length: Fy:

0 mm 280 MPa

Weld Category:

GP

Length:

0 mm

Length: Fy:

0 mm 280 MPa

Weld Category:

GP

Length:

0 mm

Fy:

260 MPa

Weld Category:

GP

Strength Grade:

Normal

Dimensions (LxWxT): 575x250x20 mm Plate Strength Grade: Normal Full Contact: YES

Fy:

350 MPa

Welds: Weld Strength Grade:

6 mm Normal

Weld Category: Weld Inside Flange:

SP NO

Bolts:

M20

Bolt Procedure:

Snug

Top Web Stiffener: Dimensions (WxT): 86x6 mm Plate Length: Full Plate Strength Grade: Normal Welds: Weld Strength Grade: Weld Length:

6 mm Normal Full

Bottom Web Stiffener: Dimensions (WxT): 86x6 mm Plate Length: Full Plate Strength Grade: Normal Welds: Weld Strength Grade: Weld Length:

6 mm Normal Full

Flange Doubler: Position: Both Dimensions (LxWxT): 275x72x12 mm Plate Strength Grade: Normal Welds: Weld Strength Grade:

6 mm Normal

CONNECTION 13 - RIGHT BASEPLATE ------------------------------Member:

12

905

SPACE GASS 12 User Manual Bolt Threads: Bolts: Pitch: Prying Factor:

Include 4 360 mm 0.71

Bolt Strength Grade: Embedded Length: Gauge:

Normal 195 mm 120 mm

Concrete: Concrete: Dimensions (LxWxD):

CONCRETE-20 775x450x395 mm

Type:

Rectangular

Grout: Thickness:

20 mm

Fc:

25 MPa

AS4100 STEEL CONNECTION DESIGN SUMMARY (*=Failure, #=Warning) -------------------------------------- ($=Min design action non-compliance) (D=Design, C=Check) Plate or Stress Conn Ratio 1 D

Crit

Title/Type

Seat/Cleat

Bolts

Welds

Case

Left baseplate

Base Plate

4M24

6 mm CFW SP

11

575x250x20 mm

4.6N/S

Plate

12M20

Web welds

11

885x195x25 mm Stiffener Top 84x12 mm Stiffener Bot 84x12 mm Flange Doublers 70x16 mm

8.8N/TB FSBW SP Flange welds FSBW SP

550x200x25 mm

8M20

0.76

3 D# Left knee 0.92

7 D

Ridge

Web weld

10

0.88 8.8N/TB 6 mm CFW SP Flange weld FSBW SP 11 D 0.96

13 D 0.57

906

Right knee

Right baseplate

Plate

8M20

Web welds

885x195x25 mm Stiffener Top 86x6 mm Stiffener Bot 86x6 mm Flange Doublers 72x12 mm

8.8N/TB 6 mm CFW SP Flange welds FSBW SP

Base Plate

4M20

6 mm CFW SP

14

10

Portal Frame Connection Design 575x250x20 mm

4.6N/S

AS4100 CALCULATIONS FOR CONNECTION 1 - LEFT BASEPLATE ----------------------------------------------------Design/Check: Design Critical load case: 11 out of 10-14 Utilization ratio: 0.76 Supported d bf tf tw r fyf fyw

= = = = = = = =

Base plate

= 575x250x20 mm (Fy = 250 MPa, Fu = 410 MPa)

Weld:

= 6 mm CFW SP (Fu = 410 MPa)

Bolt:

= 4M24 4.6N/S sp = 360 mm lec = 195 mm

Pass

530 UB 92.4 533 mm 209 mm 15.6 mm 10.2 mm 14 mm 300 MPa 320 MPa

sg = 140 mm

Concrete:

CONCRETE-20 (Length = 775 mm, Width = 450 mm, Depth = 395 mm)

Grout:

Strength = 25 MPa, Thickness = 20 mm

Design actions: N* Vy* Vz* My* Mz* Check 8:

= = = = =

111.21 kN Tension (Not used) 77.73 kN 0 kN 0 kNm (Not used) 0 kNm (Not used)

Base plate tension yielding Yield line factor alpha = 8.86 mm fNtp = 797.77 kN fNtp > 111.21 kN

Check 9:

Pass

Capacity of weld at column base fVw = 0.83 kN/mm Resultant stress = 0.14 kN/mm fVw > Resultant Stress

Check 10:

Pass

Capacity of anchor bolts in tension fNtb = 320.81 kN Nt = 111.21 kN fNtb > Nt

Pass

907


fNct = 258.05 kN fNtf = 112.96 kN fNct > fNtf Check 7:

Pass

Shear transfered by anchor bolts nbv = 2 nbt = 4 fVfb = 51.43 kN fVcex = 29.16 kN fVcey = 60.8 kN fVcp = 580.33 kN Vres = 77.73 kN

Check 11:

fVfb > Vres / nbv

Pass

fVcex > Vx / nbt

Pass

fVcey > Vy / nbt

Pass

fVcpx > Vx / nbt

Pass

fVcpy > Vy / nbt

Pass

Anchor bolts for horizontal shear and tension Check 10 must be satisfied: Check 7 must be satisfied: (A)^2 + (B)^2 < 1 A = Vres / (nbv x fVfb) B = Nt / (fNtb)

AS4100 CALCULATIONS FOR CONNECTION 3 - LEFT KNEE -----------------------------------------------Design/Check: Design Critical load case: 11 out of 10-14 Utilization ratio: 0.92 Supported d bf tf tw r fyf fyw

= = = = = = = =

360 UB 50.7-A 689.1 mm 171 mm 11.5 mm 7.3 mm 11.4 mm 300 MPa 320 MPa

Angle

= 2.99°

End plate

= 885x195x25 mm (Fy = 250 MPa, Fu = 410 MPa)

Transverse stiffeners Top = 84x12 mm Bottom = 84x12 mm Web welds

908

= FSBW SP (Fu = 410 MPa)

Supporting d bf tf tw r fyf fyw

= = = = = = = =

Pass Pass Pass

Pass


Portal Frame Connection Design Flange welds = FSBW SP (Fu = 410 MPa) Top stfr. welds = 8 mm CFW GP (Fu = 410 MPa) Bot stfr. welds = 8 mm CFW GP (Fu = 410 MPa) Bolts

= 12M20 8.8N/TB (Fu = 830 MPa)

sg sp2 spo ae

= = = =

120 mm 141.52 mm 65 mm 30 mm

sp1 sp3 spi

= 0 mm = 80 mm = 65 mm

Column flange doubler plate Size = 70x16 mm Design actions: N* Vy* Vz* My* Mz* kNm)

= = = = =

71.58 kN Tension -116.66 kN (Actual = -116.66 kN, Minimum = 40 kN) 0 kN (Not used) 0 kNm (Not used) -514.77 kNm (Actual = -514.77 kNm, Minimum = 268.2

Design moment > Member section capacity Check 1: Detailing requirement Plate depth End plate width bi >= bfb + 20 mm bi <= bfc + 20 mm Bolt gauge sg <= bfb sg <= bfc - 2.5 * df sg >= 120 mm Bolt pitches sp1, sp2, sp3 >= 70 mm Edge distance aev >= 1.5 * df aev <= 2.5 * df aeh >= 1.25 * df Check limits Table 3 - ASI Connection Design Guide 12

Warning

Pass Pass Pass Pass Pass Pass Pass Pass Pass Pass Pass

Check 2: Flange welds to beam Full penetration butt weld - No design check neccessary Check 3: Web welds to beam Full penetration butt weld - No design check neccessary Check 4: Bolts at tension flange Design requirement: ratio fMbt > M* + Maxial* 0.88 Tension bolt moment capacity, fMbt = 613.24 kNm End plate design moment, M* = -514.77 kNm Maxial* = 22.22 kNm Single bolt tension capacity = 162.68 kN Sum of bolt lever arms = 1884.8 mm

Pass

909


Check 5: Bolts in shear Design requirement: ratio fVfb = 555.77 kN > Vv = -116.66 kN 0.21 Total shear resisted by bolts, Vv* = -116.66 kN Single bolt shear capacity, fVdf = 92.63 kN End plate bearing capacity, fVbi = 276.75 kN No. bolts effective in shear = 6 Check 6: End plate at tension flange Design requirement: ratio fMpt > 1.11 * Min [fMbt and fMs] 0.82 End plate yield capacity, fMpt = 679.84 kNm Bolt moment capacity, fMbt = 613.24 kNm Section moment capacity, fMs = 502.87 kNm Check 7: End plate in shear Design requirement: ratio fVpe > Nft / nbp 0.48 fVpu > Nft / nbp 0.32 Horizontal shear yielding capacity, fVpe = 548.44 kN Horizontal shear rupture capacity, fVpu = 835.79 kN Total design tension force, Nft = 791.46 kN Total of bolt rows resisting tension force, nbp = 3

Pass

Pass

Pass Pass

Check 8: Stiffener for end plate N/A - No end plate stiffener Check 9: Design capacity of stiffener welds to end plate N/A - No end plate stiffener Check 10: Local bending of column flange at beam tension flange Design requirement: ratio fMct > 1.11 * Min [fMbt and fMs] 1.54 Stiffener Column flange capacity, fMct = 362.3 kNm Section moment capacity, fMs = 502.87 kNm Bolt group moment capacity, fMbt = 613.24 kNm Yield line parameter, Yc = 5513.85 mm Check 11: Local yielding of column flange at beam tension flange Design requirement: ratio fRwt > Nft 2.15 Stiffener Unstiffened column web yield capacity, fRwt = 368.08 kN Total design tension force, N*ft = 791.46 kN Top flange to end of column = 97.95 mm Check 12: Local yielding of column flange at beam compression flange Design requirement: ratio fRwy > N*fc 1.75 Stiffener Unstiffened column web yield capacity, fRwy = 414.94 kN Total design compression force, N*fc = 725.87 kN Check 13: Column web cripping at beam compression flange Design requirement: ratio fRwc > N*fc 2.35

910

Stiffener

Portal Frame Connection Design Unstiffened column web crippling capacity, fRwc = 309.22 kN Total design compression force, N*fc = 725.87 kN Check 14: Column web compression buckling Design requirement: ratio fRwb > N*fc 1.03 Stiffener Unstiffened column web compression buckling capacity, fRwb = 705.48 kN Total design compression force, N*fc = 725.87 kN Check 15: Unstiffened column web panel in shear Design requirement: ratio fVc > Vc* 0.77 Design capacity of column web in shear, fVc = 939.44 kN Column web pannel shear force, Vc* = 725.87 kN Column axial capacity, fNs = 3398.4 kN Check 16: Local bending of column flange with flange doubler plates at beam tension flange Design requirement: ratio fMctd > 1.11 * Min [fMbt and fMs] 0.82 Column (flange+doubler) capacity, fMctd = 679.9 kNm Bolt group design capacity, fMbt = 613.24 kNm Section moment capacity, fMs = 502.87 kNm Yield line parameter, Yc = 5513.85 mm Flange doubler plate requirements: bsd > [bfb - (twc + 2 * rc)] / 2 bsd < [bfc - (twc + 2 * rc) - 2 * fillet rad.] / 2 dsd > tfb + 5.0 * (ti + tfc + td)

Pass

Pass

Pass Pass Pass

Check 17: Local yielding of column web with plates at beam tension flange N/A - no web with doubler plate at beam tension flange Check 18: Local yielding of column web with plates at beam compression flange N/A - no web with doubler plate at beam compression flange Check 19: Crippling of column web with doubler plate at beam compression flange N/A - no web with doubler plate at beam compression flange Check 20: Compression buckling of column web with doubler plates N/A - no web with doubler plate Check 21: Column web panel with doubler plates in shear N/A - no web with doubler plate Check 22: Column with transverse stiffeners Design requirement: fMcts > 1.11 * Min [fMbt and fMs] fRfts > N*ts fRftw > N*ts Geometry check for trans. stiffeners: bs >= (bfb-twb) / 2 bs >= (bfb / 3 - twc / 2)

at tension flange ratio 0.61 0.9 0.92

Pass Pass Pass Pass Pass

911

SPACE GASS 12 User Manual bs <= (bfc-twc) / 2 ds >= 1.8 * bs ts >= 0.5 * tfb fMcts = 908.99 kNm fMbt = 613.24 kNm, fMs = 502.87 kNm Nts = 423.38 kN fRfts = 471.74 kN, fRftw = 460.89 kN Yield line parameter, Ycs = 7371.78 mm Check 23: Column with transverse stiffeners Design requirement: Stiffener: fRfcy > N*cs fRfcb > N*cs Welds to stiffeners: fRfcw > N*cs - fRwy Geometry check for trans. stiffeners: bs >= (bfb-twb) / 2 bs >= (bfb / 3 - twc / 2) bs <= (bfc-twc) / 2 ds >= 1.8 * bs ts >= 0.5 * tfb fRfcy = 894.54 kN, fRfcb = 1223.95 kN Ncs = 725.87 kN fRfcw = 1575.72 kN, fRwy = 414.94 kN

Pass Pass Pass

at compression flange ratio 0.81 0.59

Pass Pass

0.2

Pass Pass Pass Pass Pass Pass

Check 24: Column with transverse diagonal shear stiffeners N/A - no web with transverse plate

AS4100 CALCULATIONS FOR CONNECTION 7 - RIDGE -------------------------------------------Design/Check: Design Critical load case: 10 out of 10-14 Utilization ratio: 0.88 Supported d bf tf tw r fyf fyw

= = = = = = = =

Angle

= 5.99°

End plate

= 550x200x25 mm (Fy = 250 MPa, Fu = 410 MPa)

Flange welds

= FSBW SP (Fu = 410 MPa)

Web welds


Bolts

= 8M20 8.8N/TB (Fu = 830 MPa)

912

360 UB 50.7 356 mm 171 mm 11.5 mm 7.3 mm 11.4 mm 300 MPa 320 MPa

Pass


sg sp2 spo ae

= = = =

120 mm 141.52 mm 65 mm 30 mm

Design actions: N* Vy* Vz* My* Mz* kNm) Check 1: End plate: Bolt gauge:

Edge dist.:

= = = = =

sp1 sp3 spi

-40.77 kN Compression 67.36 kN (Actual = -1.24 kN, Minimum = 67.36 kN) 0 kN (Not used) 0 kNm (Not used) -118.63 kNm (Actual = -118.63 kNm, Minimum = 114.88

Detailing limitations bi >= bf + 20 sg <= bf sg >= 120 mm sp2 >= 70 mm ae >= 30 mm ae <= 2.5 bolt diameter 40 mm <= spo <= 75 mm Spacing for bolt at haunch is not sufficient Plate depth

Check 2:

Capacity of welds to beam flanges Check not required for butt weld

Check 3:

Capacity of welds to beam web Web axial force, Nw = -15.98 kN Web bending moment, Mw = -18.77 kNm Web shear force, Vy = 0.11 kN/mm Web shear force, Vz = -0.61 kN/mm Web resultant shear force = 0.62 kN/mm Weld capacity = 0.83 kN/mm Weld capacity > Resultant shear force

Check 4:

= 0 mm = 0 mm = 65 mm

Pass Pass Pass Pass Pass Pass Pass Pass Pass

Pass

Capacity of bolts at tension flange Single bolt tension capacity = 162.68 kN Number of tension bolts = 4 Sum of bolt lever arms = 689.94 mm fMbt = 224.48 kNm Mdesign = -118.63 kNm Maxial = -6.77 kNm fMbt > |MDesign| + Maxial

Check 5:

Capacity of bolts in shear Total shear resisted (V*) = 67.36 kN Bolts resisting shear = 4 Bolt capacity (fVdf) = 92.63 kN Bolt group capacity (fVfb) = 370.51 kN fVfb > V*

Check 6:

Pass

Pass

Capacity of end plate at tension flange

913


fMpt = 283.57 kNm fMbt = 224.48 kNm fMs = 229.75 kNm fMpt > 1.11 x Min[fMbt, fMs]

Pass

Check 7:

Capacity of end plate in shear Horiz. shear (Vh*) = 160.89 kN Horiz. shear yield capacity (fVpe) = 562.5 kN Horiz. shear rupture capacity (fVpu) = 863.46 kN Min of [fVpu, fVpe] > Vh* Pass

Check 8:

Requirement for stiffener to end plate No stiffener - check not required

Check 9:

Capacity of stiffener welds to end plate No stiffener - check not required

AS4100 CALCULATIONS FOR CONNECTION 11 - RIGHT KNEE -------------------------------------------------Design/Check: Design Critical load case: 14 out of 10-14 Utilization ratio: 0.96 Supported d bf tf tw r fyf fyw

= = = = = = = =

360 UB 50.7-A 689.1 mm 171 mm 11.5 mm 7.3 mm 11.4 mm 300 MPa 320 MPa

Supporting d bf tf tw r fyf fyw

= = = = = = = =

Angle

= 2.99°

End plate

= 885x195x25 mm (Fy = 250 MPa, Fu = 410 MPa)


Transverse stiffeners Top = 86x6 mm Bottom = 86x6 mm Web welds Flange welds Top stfr. welds Bot stfr. welds

= = = =

Bolts

= 8M20 8.8N/TB (Fu = 830 MPa)

sg sp2 spo ae

= = = =

914

6 mm FSBW 6 mm 6 mm

CFW SP SP (Fu CFW GP CFW GP

120 mm 141.52 mm 65 mm 30 mm

(Fu = = 410 (Fu = (Fu =

410 MPa) MPa) 410 MPa) 410 MPa)

sp1 sp3 spi

Pass

= 0 mm = 0 mm = 65 mm


Column flange doubler plate Size = 72x12 mm Design actions: N* Vy* Vz* My* Mz*

= = = = =

-65.33 kN Compression 78.19 kN (Actual = 78.19 kN, Minimum = 40 kN) 0 kN (Not used) 0 kNm (Not used) 325.84 kNm (Actual = 325.84 kNm, Minimum = 268.2 kNm)

Check 1: Detailing requirement Plate depth End plate width bi >= bfb + 20 mm bi <= bfc + 20 mm Bolt gauge sg <= bfb sg <= bfc - 2.5 * df sg >= 120 mm Bolt pitches sp1, sp2, sp3 >= 70 mm Edge distance aev >= 1.5 * df aev <= 2.5 * df aeh >= 1.25 * df Check limits Table 3 - ASI Connection Design Guide 12

Pass Pass Pass Pass Pass Pass Pass Pass Pass Pass Pass

Check 2: Flange welds to beam Full penetration butt weld - No design check neccessary Check 3: Web welds to beam Design requirement: SQRT(vz^2+vy^2) <= fVw Web shear force, Vv = 78.19 kN/mm vz = 0.8 kN/mm, vy = 0.06 kN/mm fVw = 0.83 kN/mm

ratio 0.96

Check 4: Bolts at tension flange Design requirement: ratio fMbt > M* + Maxial* 0.74 Tension bolt moment capacity, fMbt = 441.53 kNm End plate design moment, M* = 325.84 kNm Maxial* = 0 kNm Single bolt tension capacity = 162.68 kN Sum of bolt lever arms = 1357.04 mm Check 5: Bolts in shear Design requirement: ratio fVfb = 370.51 kN > Vv = 78.19 kN 0.21 Total shear resisted by bolts, Vv* = 78.19 kN Single bolt shear capacity, fVdf = 92.63 kN End plate bearing capacity, fVbi = 276.75 kN No. bolts effective in shear = 4

Pass

Pass

Pass

Check 6: End plate at tension flange

915

SPACE GASS 12 User Manual Design requirement: ratio fMpt > 1.11 * Min [fMbt and fMs] 0.83 End plate yield capacity, fMpt = 589.88 kNm Bolt moment capacity, fMbt = 441.53 kNm Section moment capacity, fMs = 502.87 kNm Check 7: End plate in shear Design requirement: ratio fVpe > Nft / nbp 0.41 fVpu > Nft / nbp 0.27 Horizontal shear yielding capacity, fVpe = 548.44 kN Horizontal shear rupture capacity, fVpu = 835.79 kN Total design tension force, Nft = 449.54 kN Total of bolt rows resisting tension force, nbp = 2

Pass

Pass Pass

Check 8: Stiffener for end plate N/A - No end plate stiffener Check 9: Design capacity of stiffener welds to end plate N/A - No end plate stiffener Check 10: Local bending of column flange at beam tension flange Design requirement: ratio fMct > 1.11 * Min [fMbt and fMs] 1.4 Stiffener Column flange capacity, fMct = 349.93 kNm Section moment capacity, fMs = 502.87 kNm Bolt group moment capacity, fMbt = 441.53 kNm Yield line parameter, Yc = 5325.63 mm Check 11: Local yielding of column flange at beam tension flange Design requirement: ratio fRwt > Nft 1.22 Stiffener Unstiffened column web yield capacity, fRwt = 368.08 kN Total design tension force, N*ft = 449.54 kN Top flange to end of column = 97.95 mm Check 12: Local yielding of column flange at beam compression flange Design requirement: ratio fRwy > N*fc 0.65 Pass Unstiffened column web yield capacity, fRwy = 787.64 kN Total design compression force, N*fc = 510.89 kN Check 13: Column web cripping at beam compression flange Design requirement: ratio fRwc > N*fc 0.8 Unstiffened column web crippling capacity, fRwc = 638.73 kN Total design compression force, N*fc = 510.89 kN

Pass

Check 14: Column web compression buckling Design requirement: ratio fRwb > N*fc 0.72 Pass Unstiffened column web compression buckling capacity, fRwb = 705.48 kN Total design compression force, N*fc = 510.89 kN Check 15: Unstiffened column web panel in shear

916

Portal Frame Connection Design Design requirement: fVc > Vc* Design capacity of column web in shear, fVc Column web pannel shear force, Vc* = 510.89 Column axial capacity, fNs = 3398.4 kN

ratio 0.54 = 939.44 kN kN

Check 16: Local bending of column flange with flange doubler plates at beam tension flange Design requirement: ratio fMctd > 1.11 * Min [fMbt and fMs] 0.93 Column (flange+doubler) capacity, fMctd = 529.39 kNm Bolt group design capacity, fMbt = 441.53 kNm Section moment capacity, fMs = 502.87 kNm Yield line parameter, Yc = 5325.63 mm Flange doubler plate requirements: bsd > [bfb - (twc + 2 * rc)] / 2 bsd < [bfc - (twc + 2 * rc) - 2 * fillet rad.] / 2 dsd > tfb + 5.0 * (ti + tfc + td)

Pass

Pass

Pass Pass Pass

Check 17: Local yielding of column web with plates at beam tension flange N/A - no web with doubler plate at beam tension flange Check 18: Local yielding of column web with plates at beam compression flange N/A - no web with doubler plate at beam compression flange Check 19: Crippling of column web with doubler plate at beam compression flange N/A - no web with doubler plate at beam compression flange Check 20: Compression buckling of column web with doubler plates N/A - no web with doubler plate Check 21: Column web panel with doubler plates in shear N/A - no web with doubler plate Check 22: Column with transverse stiffeners Design requirement: fMcts > 1.11 * Min [fMbt and fMs] fRfts > N*ts fRftw > N*ts Geometry check for trans. stiffeners: bs >= (bfb-twb) / 2 bs >= (bfb / 3 - twc / 2) bs <= (bfc-twc) / 2 ds >= 1.8 * bs ts >= 0.5 * tfb fMcts = 669.9 kNm fMbt = 441.53 kNm, fMs = 502.87 kNm Nts = 81.46 kN fRfts = 260.06 kN, fRftw = 355.69 kN Yield line parameter, Ycs = 6739.25 mm

at tension flange ratio 0.73 0.31 0.23

Pass Pass Pass Pass Pass Pass Pass Pass

Check 23: Column with transverse stiffeners at compression flange

917

SPACE GASS 12 User Manual Design requirement: Stiffener: fRfcy > N*cs fRfcb > N*cs Welds to stiffeners: fRfcw > N*cs - fRwy Geometry check for trans. stiffeners: bs >= (bfb-twb) / 2 bs >= (bfb / 3 - twc / 2) bs <= (bfc-twc) / 2 ds >= 1.8 * bs ts >= 0.5 * tfb fRfcy = 1044.81 kN, fRfcb = 1030.39 kN Ncs = 510.89 kN fRfcw = 1181.79 kN, fRwy = 787.64 kN

ratio 0.49 0.5

Pass Pass

-0.23

Pass Pass Pass Pass Pass Pass

Check 24: Column with transverse diagonal shear stiffeners N/A - no web with transverse plate

AS4100 CALCULATIONS FOR CONNECTION 13 - RIGHT BASEPLATE ------------------------------------------------------Design/Check: Design Critical load case: 10 out of 10-14 Utilization ratio: 0.57 Supported d bf tf tw r fyf fyw

= = = = = = = =


Base plate

= 575x250x20 mm (Fy = 250 MPa, Fu = 410 MPa)

Weld:


Bolt:

= 4M20 4.6N/S sp = 360 mm lec = 195 mm

sg = 120 mm

Concrete:

CONCRETE-20 (Length = 775 mm, Width = 450 mm, Depth = 395 mm)

Grout:

Strength = 25 MPa, Thickness = 20 mm

Design actions: N* Vy* Vz* My* Mz*

918

= = = = =

-77.15 kN Compression (Not used) 40.64 kN 0 kN 0 kNm (Not used) 0 kNm (Not used)

Pass

Portal Frame Connection Design Check 1:

Capacity for bearing on concrete support Base plate area = 143750 mm^2 Geometrically similar area A2 = 261141.3 mm^2 fNc = 2092.5 kN >= Nc* = 77.15 kN

Check 2:

Capacity of steel base plate fNs = 3774.15 kN >= Nc* = 77.15 kN a1 = 34.33 mm a2 = 41.4 mm a4 = 83.44 mm a5 = 742 mm kx = 2.271942 X = 0.03850627 lambda = 0.2250999 ao = 41.4 mm

Check 3: Weld length: Weld stress:

Pass

Pass

Capacity of weld at column base Lx = 418 mm Ly = 947.6 mm Vx = 0 kN/mm Vy = 0.04 kN/mm Plate fully contacts with column SQRT(Vx^2 + Vy^2) = 0.04 kN/mm

Weld strength: fVw = 0.83 kN/mm SQRT(Vx^2 + Vy^2) < fVw Check 4:

Pass

Horizontal shear transfered by fiction Slip factor = 0.4 Compression force = 77.15 kN fVcf = 21.6 kN Vres = 40.64 kN fVcf > Vres is not satisfied - Anchor bolts check is

required Check 7:

Shear transfered by anchor bolts nbv = 2 nbt = 4 fVfb = 35.71 kN fVcex = 27.1 kN fVcey = 55.5 kN fVcp = 548.54 kN Vres = 40.64 kN fVfb > Vres / nbv

Pass

fVcex > Vx / nbt

Pass

fVcey > Vy / nbt

Pass

fVcpx > Vx / nbt

Pass

fVcpy > Vy / nbt

Pass

919

Cable Analysis Cable analysis This worked example demonstrates the input and analysis of a 30m tall, guyed mast. The catenary cable equations are used to calculate the axial force in a nominal guy member, which is then compared to the result obtained from SPACE GASS.

A non-linear analysis is the only type of analysis that can be performed on a structure containing cable members due to their highly non-linear behaviour. The guyed mast considered in this example has the following basic properties. Height: Number of guys: Radial guy spacing: Guy connections at: Distance from base: Guys: Mast:

30m 3 sets of 3 120 15m, 22.5m and 30m 12m 10mm steel cable 406x9.5CHS

Dead load (DL):

Self weight (calculated by SPACE GASS)

The uniformly distributed dead load is not the only load that the structure would be subject to in real life, however it is the only one considered here. The load cases are limited in order to simplify the example. In this example, the only type of load applied is an UDL. You can apply point loads to cable members, however they must be applied as node loads rather than member concentrated loads.

921


Elevation of guyed mast

922

Cable Analysis

Method of input It was not possible to input the guyed mast using the structure wizard due to its unusual geometric configuration. All of the data input was performed using either graphical tools or datasheets. Node restraints and member fixities After the structural geometry was generated, node restraints of FFFFFF were applied to nodes 1, 5, 6 and 7 using the graphical restraint input facility. Even though the guyed members are to be pin connected to the mast and to their base, a member end fixity of FFFFFF was specified. This is because a member end fixity code of FFFRRR would yield the same result as a code of FFFFFF for cable members (ie. cables have no moment capacity). Loads Loading due to the self weight of the structure was input using a datasheet.

Cables have no moment capacity. Hence, intermediate nodes on cables must have all their rotational degrees of freedom restrained (ie. use RRRFFF). Input check As a final check before the analysis was initiated, an output report containing the complete structural data was viewed. Any errors in the data were corrected and the model was then ready for analysis.

923


Analysis procedure A non-linear (2nd order) analysis was performed in which both P- and P- effects were activated, while axial shortening was not.

924

Cable Analysis

Analysis results In the absence of any lateral loads, the guys simply deflect vertically under self weight as shown in the following deformed shape diagram.

SPACE GASS model

925


Deformed shape

This report extract shows all of the input data for the model, together with the intermediate displacements, forces and moments for guy member 12. Following the report, we compare the SPACE GASS results for member 12 with a theoretical formular.

ANALYSIS STATUS REPORT ---------------------Job name ...... Guyed Mast Location ...... C:\Samples\Mixed

926

Cable Analysis

This is a guyed mast analysed for the SPACE GASS worked example appendices. Length units ......................... Section property units ............... Material strength units .............. Mass density units ................... Temperature units .................... Force units .......................... Moment units ......................... Mass units ........................... Acceleration units ................... Translation units .................... Stress units .........................

m mm MPa kg/m^3 Celsius kN kNm kg g's mm MPa

Nodes ................................ 32765) Members .............................. 32765) Plates ............................... 32765) Restrained nodes ..................... 32765) Nodes with spring restraints ......... 32765) Section properties ................... 5000) Material properties .................. 999) Constrained nodes .................... 32765) Member offsets ....................... 32765)

7

(

12

(

0

(

4

(

0

(

2

(

1

(

0

(

0

(

0

(

0

(

0

(

0

(

Node loads ........................... 250000) Prescribed node displacements ........ 250000) Member concentrated loads ............ 250000) Member distributed forces ............

927


250000) Member distributed torsions .......... 250000) Thermal loads ........................ 250000) Member prestress loads ............... 250000) Plate pressure loads ................. 250000) Self weight load cases ............... 10000) Combination load cases ............... 10000) Load cases with titles ............... 10000) Lumped masses ........................ 250000) Spectral load cases .................. 10000) Static analysis ...................... Dynamic analysis ..................... Response analysis .................... Buckling analysis .................... Ill-conditioned ...................... Non-linear convergence ............... Frontwidth ........................... Total degrees of freedom ............. Static load cases .................... 10000) Mass load cases ...................... 10000)

NODE COORDINATES (m) ----------------

Node

X Coord

Y Coord

Z Coord

1 2

0.000 0.000

0.000 15.000

0.000 0.000

928

0

(

0

(

0

(

0

(

1

(

0

(

0

(

0

(

0

(

Y N N N N Y 12 18 1

(

1

(

Cable Analysis

3 4 5 6 7

0.000 0.000 -12.000 6.000 6.000

22.500 30.000 0.000 0.000 0.000

0.000 0.000 0.000 10.392 -10.392

MEMBER DATA (deg,kNm/rad,m) ----------- (F=Fixed, R=Released) (*=Cable length) Dir Dir Dir Memb Node A Node B Memb Angle Node Axis Type Node A Node B Fixity Fixity Length 1 FFFFFF 2 FFFFFF 3 FFFFFF 4 FFFFFF 5 FFFFFF 6 FFFFFF 7 FFFFFF 8 FFFFFF 9 FFFFFF 10 FFFFFF 11 FFFFFF 12 FFFFFF

0.00 FFFFFF 0.00 FFFFFF 0.00 FFFFFF 0.00 FFFFFF 0.00 FFFFFF 0.00 FFFFFF 0.00 FFFFFF 0.00 FFFFFF 0.00 FFFFFF 0.00 FFFFFF 0.00 FFFFFF 0.00 FFFFFF

Sect Mat

Norm

1

2

1

1

Norm

2

3

1

1

Norm

3

4

1

1

Cabl

2

5

2

1

Cabl

3

5

2

1

Cabl

4

5

2

1

Cabl

2

6

2

1

Cabl

3

6

2

1

Cabl

4

6

2

1

Cabl

2

7

2

1

Cabl

3

7

2

1

Cabl

4

7

2

1

15.000 7.500 7.500 19.209 25.500 32.311 19.209 25.500 32.311 19.209 25.500 32.311

NODE RESTRAINTS (kN/m,kNm/rad)

929


--------------- (F=Fixed, R=Released, S=Spring, *=General) Rest X Axial Y Axial Rotation Y Rotation Z Rotation Node Code Stiffness Stiffness Stiffness Stiffness Stiffness

Z Axial X Stiffness

1 FFFFFF 5 FFFFFF 6 FFFFFF 7 FFFFFF

SECTION PROPERTIES (mm,mm^2,mm^4,deg) -----------------Sect Name Source 1

406.4x9.5 CHS Aust300 2 Guy circle User

Mark

Shape

S1

Circular

S2

Solid

tube

Area of Torsion Y-Axis Z-Axis Princ Sect Section Constant Area Shr Area Angle

Y-Axis

Z-Axis

Mom of In

Mom of In

Shr

1 1.1800E+04 4.6700E+08 2.3300E+08 2.3300E+08 Infinite Infinite 0.00 2 7.8540E+01 9.8175E+02 4.9087E+02 4.9087E+02 Infinite Infinite 0.00 Sect Shape Btw/Bbw Tt/Tb 1 0.00

930

Trans Mir Rotate

D

Bt/Bb

406.00

0.00

Tw/Rr

Circular tube 0.00 9.50

No

No

0.00

Cable Analysis

0.00 0.00 2 0.00

0.00 0.00 Solid circle 0.00 0.00

No

No

0.00

10.00

0.00 0.00

0.00

0.00

0.00

MATERIAL PROPERTIES (MPa,kg/m^3,strain/degC) ------------------Young's Poisson's Coeff of Concrete Matl Material Name Modulus Ratio Expansion Strength 1 STEEL 1.170E-05

2.0000E+05

Mass Density

0.25 7.8500E+03

SELF WEIGHT (g's) ----------Load Case

X-Axis Accel'n

Y-Axis Accel'n

Z-Axis Accel'n

1

0.000

-1.000

0.000

INTERMEDIATE DISPLACEMENTS (m,mm) -------------------------- (*=Maximum, #=Minimum) Memb 12, Case 1 (Non-linear): Non-linear (Small, Sec, Resid): P-, P-, 2 Itns, 99.963% Cnv (Def gov) Station Local Y Location Transl'n

Global X Local Z Transl'n Transl'n

Global Y

Global Z

Local X

Transl'n

Transl'n

Transl'n

0.000 -0.108

0.000 0.000

-0.291

0.000

0.270

931


3.231 -69.653 6.462 -124.732 9.693 -164.996 12.924 -190.083 16.155 -199.618# 19.387 -193.215 22.618 -170.474 25.849 -130.980 29.080 -74.303 32.311 0.000*

-32.365 0.000 -57.964 0.000 -76.646 0.000 -88.253 0.000 -92.627# 0.000 -89.600 0.000# -79.003 0.000 -60.659 0.000 -34.387 0.000* 0.000* 0.000

-25.718

56.059

-46.029

100.397

-0.318#

-61.036

132.754

-0.260

-70.545

152.860

-0.053

-74.352#

160.435*

0.233

-72.247

155.192

0.526

-63.998

136.838

0.738

-49.374

105.066

0.786*

-28.130

59.561

0.000*

-0.162

0.576

0.000#

0.000

INTERMEDIATE FORCES AND MOMENTS (m,kN,kNm) ------------------------------- (*=Maximum, #=Minimum) Memb 12, Case 1 (Non-linear): Non-linear (Small, Sec, Resid): P-, P-, 2 Itns, 99.963% Cnv (Def gov) Station Y-Axis Location Moment

Axial Z-Axis Force Moment

0.000 0.000 3.231 0.000 6.462 0.000 9.693 0.000

-1.560# 0.000 -1.542 0.000 -1.524 0.000 -1.506 0.000

932

Y-Axis

Z-Axis

X-Axis

Shear

Shear

Torsion

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

Cable Analysis

12.924 0.000 16.155 0.000 19.387 0.000 22.618 0.000 25.849 0.000 29.080 0.000 32.311 0.000

-1.487 0.000 -1.469 0.000 -1.451 0.000 -1.433 0.000 -1.415 0.000 -1.397 0.000 -1.379* 0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

The following catenary cable equation from Hibbeler (15) for a single catenary element can be used to verify the results for member 12 shown above. As you can see, it was necessary to resolve the UDL to the local axis of the member (multiplying it by the cosine of the angle between the vertical). From this point the solution is straightforward, the result varying by only 0.3% (ie. 1.469kN vs. 1.465kN).

933

SPACE GASS 12 User Manual See also Members. See also Cable members.

934

Converting Old Jobs Converting old jobs SPACE GASS automatically converts all version 4.0 and newer jobs into the correct format at the time they are opened. They are then saved with the usual .SG naming convention. However, pre-version 4.0 jobs use multiple data files for each job, each of which has a filename extension of "DAT". In order to open the pre-version 4.0 files with the current version of SPACE GASS they must first be renamed to the new convention. This can be done automatically with a batch program called SGName.BAT that is supplied with SPACE GASS. In order to rename the old data files, you should first open a command (or DOS) prompt window, go to the folder containing the old data files and then run SGName from your SPACE GASS program folder. Assuming that the old files are in a folder called C:\OldData and the SPACE GASS program files are in a folder called C:\Program Files\SPACE GASS\EXE, the commands necessary to rename them are: C: CD\OldData C:\”Program Files"\”SPACE GASS"\EXE\SGName Once the files have been renamed, you can access them from the current version of SPACE GASS as normal. Naturally, they still have to be converted to the latest format, however this is done automatically as each job is opened by SPACE GASS.

935

Bibliography Bibliography 1. Harrison H.B. "Computer Methods in Structural Analysis", pp 248-251, Prentice Hall, 1973.

2. Ghali A. and Neville A.M. "Structural Analysis A Unified Classical and Matrix Approach", 2nd edition, pp 364-374, Chapman and Hall, London, 1978.

3. AS1250 - 1981 "SAA Steel Structures Code", Standards Australia, 1 The Crescent, Homebush, NSW, 2140, Australia.

4. AS4100 - 1990 "Steel Structures", Standards Australia, 1 The Crescent, Homebush, NSW, 2140, Australia.

5. SABS0162 - 1984 "Code of Practice for The Structural Use of Steel", The Council of the South African Bureau of Standards, Private Bag X191, Pretoria, Republic of South Africa.

6. BS5950 : Part 1 : 1990 "Structural Use of Steelwork in Building", British Standards Institution, 2 Park Street, London W1A 2BS.

7. NZS3404 - 1992 "Steel Structures Standard", Standards New Zealand, Wellington Trade Centre, Victoria Street, Wellington 1, New Zealand.

8. Clarke A.B. and Coverman S.H. "Structural Steelwork: Limit state design", p 49, Chapman and Hall, London, 1987.

937

SPACE GASS 12 User Manual 9. Woolcock S.T., Kitipornchai S. and Bradford M.A. "Limit State Design of Portal Frame Buildings", 1st edition, AISC, 1991.

10. Clough R.W. and Penzien J. "Dynamics of Structures", McGraw-Hill Book Company, 1975.

11. AS3990 - 1993 "Mechanical equipment - Steelwork", Standards Australia, 1 The Crescent, Homebush, NSW, 2140, Australia.

12. Wittrick W.H. and Williams F.W. "Natural Frequencies of Elastic Structures", Quarterly Journal of Mechanics and Applied Mathematics, Vol. XXIV, Pt. 3, 1971.

13. AS/NZS4600 - 1996 "Cold-Formed Steel Structures", Standards Australia, 1 The Crescent, Homebush, NSW, 2140, Australia.

14. AS3600 - 1988 "Concrete Structures", Standards Australia, 1 The Crescent, Homebush, NSW, 2140, Australia.

15. Hibbeler R.C. "Engineering Mechanics", 6th edition, Macmillan Publishing Company, 1992.

16. AISC-ASD "Specification for Structural Steel Buildings, Allowable Stress Design", American Institute of Steel Construction (AISC), June 1, 1989.

17. AISC-LRFD "Load and Resistance Factor Design Specification for Structural Steel Buildings", American Institute of Steel Construction (AISC), Dec 1, 1993.

18. Eurocode 3 "Design of Steel Structures", European Committee for Standardization (CEN), DD ENV 1993-1-1 : 1992.

938

Bibliography

19. Tessler, A. and Hughes, T.J.R., "A three-node Mindlin plate element with improved transverse shear", Computer Methods In Applied Mechanics And Engineering 50 (1985) pp 71-101

20. Tessler, A. and Hughes, T.J.R., "An improved treatment of transverse shear in the Mindlin-type four-node quadrilateral element", Computer Methods In Applied Mechanics And Engineering 39 (1983) pp 311-335

21. Liu,, J, Riggs, H.R. and Tessler, A. , "A four-node, shear-deformable shell element developed via explicit Kirchoff constraints", International Journal For Numerical Methods In Engineering, Vol. 2000, 49, pp 1065-1086

22. Batoz, J., "An explicit formulation for an efficient triangular plate-bending element", International Journal For Numerical Methods In Engineering, Vol. 18 (1982), pp 1077-1089

23. Batoz, J. and Tahar, M.B., "Evaluation of a new quadrilateral thin plate", International Journal For Numerical Methods In Engineering, Vol. 18 (1982), pp 1655-1677

24. Hancock Gregory J., "Elastic method of analysis of rigid jointed frames including second order effects", Steel Construction, Vol. 28, No. 3, September 1994

939

Index 2 2nd order analysis ........................629 See non-linear analysis ............629 3 3D renderer ..........................340, 562 A A quick frontwidth calculation method .....................................639 Absolute coordinates............397, 399 Acceleration .................................224 Access ..........................................103 Align members.............................461 Aligning plate axes ......................469 Alignment ............................196, 382 Amplitude ....................................561 Analysis .......................................617 Buckling analysis.....675, 681, 684 Dynamic frequency analysis ...653, 655 Dynamic response analysis .....664, 666 Static analysis ..................618, 641 Warnings and errors.................692 Angle sections..............175, 192, 713 Animation ....................................567 Annotation ...........................555, 817 Aperture circle ...............39, 369, 392 Arc generation..............................446 Area loads ............................244, 511 Area of section .............................175 Attach...................340, 369, 382, 392 Attachments .................................150 Auto scaling of base shear ...........666 AutoCAD .............101, 103, 106, 122 Axes .............................................130

Global axes .............. 130, 137, 552 Local axes................ 130, 137, 553 Local axes for moments and shears ....................................... 39, 590 Axial force distribution................ 684 Axial forces.................................. 620 Described................................. 620 Diagrams.................................. 561 Sign convention ....................... 137 Axis limits.................................... 590 B Base shear factor.......................... 666 Bending effective lengths ............ 713 Bending moments ........................ 620 Described................................. 620 Diagrams............................ 39, 561 Sign convention ....................... 137 Bends ........................................... 447 Bentley Structural ........ 101, 103, 106 Biaxial bending............................ 852 Bibliography .............................. 1009 Bill of materials ................... 652, 955 BIM...................................... 101, 103 Bolts............. 815, 817, 835, 885, 897 Boundary conditions.................... 170 See node restraints ................... 170 Bracing................................. 298, 303 BS5950-1 2000 code specific items ................................................. 784 Buckling analysis......................... 617 Analysis ........... 617, 631, 675, 684 Axial force distribution............ 684 Cables ...................................... 681 Effective lengths...................... 678 Load cases ............................... 684 Load factor....... 675, 681, 684, 861 Messages.................................. 641

941

SPACE GASS 12 User Manual Mode shapes ............569, 675, 684 Node restraints .........................681 Results..............................690, 959 Special considerations..............681 C Cables...........................................617 Analysis ...................617, 626, 629 Buckling analysis.....................681 Chord length ............................154 Convergence ............................626 Converted to tension-only........154 Damping ..........................626, 641 Fixity................................154, 626 Length ......................................154 Load stepping...................626, 641 Loading ............213, 218, 224, 626 Members ..........................154, 626 Worked example ......................995 CAD .....................................101, 103 CAD interface module .................122 Calculator.......................................34 Cartesian coordinates ...........397, 399 Catenary cables ............................626 See cables.................................626 Centre of gravity ..................652, 955 Changing the appearance of SPACE GASS ...................................44, 46 Characteristic concrete strength ...194 Check boxes ...................................77 Chord length.................................154 CIMSteel/2 file.............101, 103, 106 CIS/2 file......................................106 See CIMSteel/2 file..101, 103, 106 Clean-up job...................................87 Cleats ...........................815, 817, 835 Click...............................................74 Code check...........................743, 852 Codes ...........................................733 Flange restraint ................713, 733 Master-slave constraint ............196

942

Member fixity .......................... 154 Node restraint .......................... 170 Coefficient of thermal expansion. 194 Colors....................................... 44, 46 Column and beam Tee sections ... 191 Column and beam Tees ............... 742 Combination load cases ............... 226 Described................................. 226 Graphics................................... 499 Managing load cases................ 548 Text.......................................... 274 Combined stress ratio .................. 743 Limit ........................................ 743 Steel member design................ 743 Combo boxes ................................. 77 Command buttons.......................... 77 Command line options................... 65 Compression effective lengths.... 678, 713 Compression-only members154, 624, 641, 655 Concrete column design ..... 851, 852, 864 Assumptions and notes ............ 864 Auto-check mode..................... 852 Biaxial bending........................ 852 Check....................................... 852 Configuration........................... 861 Cover ....................................... 861 Cross section............................ 852 Design...................................... 852 Effective lengths...................... 852 Interaction diagram.................. 852 Load factor....... 851, 852, 861, 864 Loads ....................................... 852 Minimum load compliance...... 852 Moment magnification ............ 852 Output ...................................... 863 Reinforcement ......................... 852 Shapes...................................... 852 Voids........................................ 852 Concrete reinforcement ............... 137

Index Configuring SPACE GASS .....33, 48 Configuring the renderer................48 Connect ........................................454 Connection design........................815 Connectivity check.......................473 Constraint code ............................196 Context sensitive cursors .............369 Continuous lateral restraint ..........733 Contours.......................................562 Control Panel .................................46 Convergence624, 626, 629, 641, 655, 743, 753, 864, 883 Converting old jobs....................1007 Coordinate systems ......................130 Coordinates ..................................397 Absolute ...........................397, 399 Cartesian ..........................397, 399 Polar.................................397, 399 Relative ............................397, 399 Copying........................................548 Load cases................................548 Member loads ..........................546 Member properties...................429 Node loads ...............................545 Node properties........................428 Nodes, members or plates ........438 Plate loads ................................547 Plate properties ........................430 Steel member properties ..........712 Correction factors...........................43 Cover............................................861 CQC .............................................666 Creating a new job .........................80 Critical flange...............................762 Cross section window ..................852 Crosshair cursor .............39, 389, 391 Crossing window .........................369 CSV file ...............................101, 103 Currents................................247, 516 Curved line resolution....................39 Custom libraries ...........................888 Customizing

Property panels .......................... 57 Toolbars..................................... 53 D Damping ...................................... 233 Spectral curves......................... 233 Static analysis .................. 626, 641 Dashed lines................................... 39 Data entry ...................................... 77 Datasheet input ............................ 325 Dead loads ................................... 311 Deleting ......................................... 86 Jobs ............................................ 86 Load cases ............................... 548 Parts of the structure ........ 369, 442 Design.......................................... 697 Combined stress ratio Steel member design.... 697, 773 Convergence ............................ 697 Design groups and intermediate stations................................. 758 Design segment ...... 697, 759, 760, 765, 766, 768, 773, 777 Lateral rotation factor .............. 768 Load cases ....................... 697, 773 Load factor Steel member design.... 697, 773 Load height factor.................... 766 Member segment .... 697, 759, 760, 765, 766, 768, 773, 777 Moment magnification ............ 697 Section check........................... 760 Segment .. 697, 759, 760, 765, 766, 768, 773, 777 Steel connection design Design actions...................... 843 Design procedure ................. 843 Minimum design actions..... 817, 835 Steel member design Assumptions ........................ 777

943

SPACE GASS 12 User Manual Check mode .........................777 Combined stress ratio...697, 773 Described .............................697 Design mode ........................777 Load factor ...................697, 773 Section check .......................760 Segment ......697, 759, 760, 765, 766, 768, 773, 777 Stress ratio .......................697, 773 Torsional effects ......................697 Twist factor ..............................765 Diagram shading ............................39 Diagrams ..............................561, 562 Dialogue boxes...............................75 Closing .......................................75 Moving.......................................75 Using the keyboard ....................75 Dimensions ..................................603 Direction ......................................154 Angle........................................154 Axis..........................................154 Node.........................................154 Vector ......................................233 Displacements ..............................620 Described .................................620 Diagrams..................................561 Sign convention .......................137 DOC file.......................................103 See MS-Word ..........................103 Dongle............................................14 See Hardware lock ...............14, 31 Doppler effect ..............................516 Double-click...................................74 Drag ...............................................74 Draw.............................................431 DXF file .......................................122 Files..........101, 103, 122, 123, 124 Layer names...............................39 Dynamic frequency analysis .......230, 617, 653, 655 Frequency shift ........................655 Iterations ..................................655

944

Load cases ............................... 655 Mode shapes ... 233, 567, 653, 654, 655, 666 Natural frequencies.................. 655 Results ............................. 663, 956 Self mass.................................. 655 Stiffness matrix........................ 641 Worked example...................... 903 Dynamic response analysis.. 617, 664 Auto scaling of base shear ....... 666 Base shear factor...................... 666 Load cases ............................... 666 Mode combination method...... 666 Results ..................... 671, 672, 957 Sign of the results .................... 666 Site factor................................. 666 Site subsoil category................ 666 Spectral curve multiplier ......... 666 Vertical direction ..................... 666 Worked example...................... 903 E Eccentric effects .................. 713, 743 Compression members ............ 771 Tension members..................... 772 Edit mode............................. 410, 414 Effective lengths .......................... 713 Bending effective lengths ........ 713 Buckling analysis..................... 678 Compression effective lengths 678, 713 Concrete column effective length ............................................. 852 Steel member effective lengths 713 Eigenvalue ........................... 653, 675 Eigenvector.......................... 653, 675 Elastic critical buckling analysis . 675 See buckling analysis .............. 675 Elastic critical load analysis......... 675 See buckling analysis .............. 675 Elastic restraints........................... 170

Index See node restraints ...................170 Elastic suppprts ............................170 See node restraints ...................170 End fixity .....................................626 See member fixity............154, 626 End moment ratios and other factors .................................................770 Enveloping ...................................566 Graphics ...................................566 Reports .....................................867 Errors ...........................................692 Analysis ...................................692 Steel member design................811 Text file....................................282 ETABS.........................................103 Euler buckling capacity.......631, 641, 675, 678 Examples......................................995 Cable analysis ..........................995 Portal frame analysis................903 Portal frame connection design971 Portal frame member design ....961 Excel ............................................103 Exporting CIMSteel/2 file ................103, 106 CIS/2 file..........................103, 106 CSV file ...................103, 106, 835 DWG file .................................835 DXF file ...................122, 124, 835 IFC file.............................103, 106 MS-Access file.................103, 835 MS-Excel file...................103, 835 MS-Word file...................103, 835 SDNF file.................................103 Step file ............................103, 106 Text file....................103, 251, 835 ZIP file .....................................103 Extend members...........................457 F Filters .....................................96, 590

Find.............................................. 586 Fixity............................................ 154 See members............................ 154 Flange restraints........... 713, 733, 763 Flexural-torsional buckling.......... 675 Flipping a section................. 175, 190 Floor loading................................ 511 See area loading....................... 511 Floor slab ..................................... 196 Folders ........................................... 34 Fonts ............................................ 867 See output ................................ 867 Forces........................................... 620 Described................................. 620 Diagrams.................................. 561 Sign convention ....................... 137 Frame data ................................... 147 Frame imperfections .................... 743 See Imperfections .................... 743 Frameworks Plus . 101, 103, 106, 122 Frequency .................................... 561 Frequency shift ............................ 655 Frontwidth ................... 632, 638, 639 Full restraint................................. 733 G Gauge........................................... 817 General colours.............................. 46 General configuration .................... 39 General restraint .......................... 170 Generate arc ................................. 446 Geometry and loads ..................... 905 Girts ............................................. 298 Global axes .................. 130, 137, 552 Graphical input Colors ........................................ 44 Cursor ...................................... 369 Dimensions ................................ 43 Display area ............................... 68 Editing ............................. 340, 369 Input................................. 340, 369

945

SPACE GASS 12 User Manual Output ..............................867, 882 Overview..................................369 Text format ................................37 Gravity .........................................224 Grid ......................................340, 386 Gridlines.......................................607 Group code...........................713, 894 H Hardware lock..........................14, 32 Haunches..............463, 815, 817, 835 Headings ......................................150 Heartbeat ........................................32 Hong Kong CP2011 code specific items.........................................791 Horizontal angle...........................595 HTML file....................................873 Page setup ................................873 Print preview............................878 I IFC file .........................101, 103, 106 Ill-conditioning and instabilities ..144 Imperfections ...............................743 Importing .....................................103 ARC file...................................103 CIMSteel/2 file ................103, 106 CIS/2 file..........................103, 106 CSV file ...........................103, 106 DXF file ...........................122, 124 IFC file.............................103, 106 Microstran file..........................103 MS-Access file.................103, 835 MS-Excel file...................103, 835 SDNF file.................................103 Spectral curve text file .............242 Step file ............................103, 106 Text file............................103, 251 ZIP file .....................................103 Incremental displacements...........641 Infotips .........................................401

946

Initiator ........................................ 253 Input methods .............................. 101 Instabilities........................... 144, 675 Installing SPACE GASS................ 32 Interaction diagram...................... 852 Intermediate member stations..... 743, 758 Intermediate nodes....... 458, 459, 460 Moving intermediate nodes ..... 460 Removing crossed member nodes ............................................. 459 Removing intermediate nodes . 458 Intersect ............................... 454, 455 Iterating the analysis-design process ................................................. 753 J Jobs ................................................ 87 Attachments............................. 150 Clean-up .................................... 87 Delete......................................... 86 Merge......................................... 83 New............................................ 81 Open .......................................... 82 Save ........................................... 85 Status ........................... 71, 95, 883 K Keyboard ..................................... 397 Input................................. 397, 399 Shortcuts .................................... 96 Kt factor....................................... 743 L Labelling and annotation ............. 555 Lateral restraint............................ 733 See flange restraints................. 733 Legal notice ..................................... 7 Libraries....................................... 106

Index Converting section names when importing or exporting.........106 Creating custom libraries .........888 Standard libraries .....................885 The library editor .....................888 Library scan code.................713, 894 Licence Agreement ..........................7 Lift off..........................................154 Line width ......................................43 Linear analysis .....129, 617, 618, 641 Linking to other programs ...........103 List boxes .......................................77 Lists................................................77 Live loads.....................................311 Load cases.....96, 129, 233, 325, 618, 629, 641, 653, 655, 666, 684, 743, 758, 817, 835, 852 Combining ...............226, 274, 499 Copying....................................548 Deleting....................................548 Load case titles viewer.............558 Manage ....................................548 Renumbering............................548 Scrolling.....................................96 Titles ........................................229 Titles text .................................275 Load factor ...................................675 Buckling analysis....675, 681, 684, 861 Concrete column design..851, 852, 861, 864 Limit ................684, 743, 852, 861 Steel member design........743, 774 Load height factor ........................766 Load height position ....713, 726, 766 Load stepping.......................626, 641 Loading diagrams.........................561 Loads............................................546 Copying member loads ............546 Copying node loads .................545 Copying plate loads .................547 Filtering loads ..........................590

See area loads .......................... 244 See combination load cases ..... 226 See load case titles................... 229 See lumped masses .................. 230 See member concentrated loads ............................................. 211 See member distributed forces 213 See member distributed torsions ............................................. 216 See moving loads..................... 526 See node loads ......................... 207 See plate pressure loads........... 222 See prescribed node displacements ............................................. 209 See prestress loads ................... 218 See sea loads.................... 247, 516 See self weight......................... 224 See spectral loads .................... 233 See thermal loads..................... 218 Local axes .................... 130, 137, 553 Local axes for moments and shears ........................................... 39, 590 Logo....................................... 60, 873 Lumped masses............................ 230 Converting static loads to masses ............................................. 508 Described................................. 230 Dynamic frequency analysis.... 655 Graphics........................... 505, 561 Text.......................................... 276 M Macros ........................................... 89 Margins........................................ 873 See page setup ......................... 873 Mass density ................................ 194 Masses ......................................... 230 See lumped masses .................. 230 Master node ................................. 196 Master-slave constraints .............. 196 Described................................. 196

947

SPACE GASS 12 User Manual Graphics ...................................426 Text ..........................................263 Material properties .......................194 Described .................................194 Graphics ...................................425 Library .............................885, 896 Text ..........................................262 MDB file ......................................101 See MS-Access ................101, 103 Measure........................................603 Member alignment ...............196, 205 Member check......................761, 774 Member concentrated loads .........211 Described .................................211 Graphics ...........................480, 561 Text ..........................................267 Member distributed forces ...........213 Described .................................213 Graphics ...........................483, 561 Text ..........................................268 Member distributed torsions ........216 Described .................................216 Graphics ...........................486, 561 Text ..........................................269 Member groups ............................727 Member imperfections .................743 See Imperfections ....................743 Member numbering......470, 638, 640 Member offsets ............................205 Described .................................205 Graphics ...................................427 Text ..........................................264 Member origins............................554 Member prestress loads................492 Described .................................220 Graphics ...........................492, 561 Text ..........................................271 Member schedule .........................122 Members ......................................154 Described .................129, 137, 154 Graphics ...................................414 Text ..........................................256

948

Menu system.................................. 68 Merging jobs.................................. 83 Meshing ....................................... 451 Microsoft ..................................... 101 Access.............................. 101, 103 Excel ................................ 101, 103 Windows.................................... 80 Word ........................................ 103 Microstation......... 101, 103, 106, 122 Microstran............................ 101, 103 Minimum design actions...... 817, 835 Mirror........................................... 441 Mode combination method .......... 666 Mode shapes ................................ 675 Buckling analysis.... 569, 675, 681, 684 Dynamic frequency analysis... 567, 653, 654, 655 Dynamic response analysis..... 233, 664, 666 Viewing mode shapes...... 567, 569 Modelling considerations............. 654 Modulus of subgrade reaction ..... 170 Moment magnification ................ 852 Moment of inertia ........................ 175 Moments ...................................... 620 Described................................. 620 Diagrams.................................. 561 Sign convention ....................... 137 Mouse ............................................ 96 The mousewheel ........................ 96 Using the mouse ........................ 74 Move............................................ 435 Moving intermediate nodes ......... 460 Moving loads ............... 249, 526, 902 MS-Excel ............................. 101, 103 MS-Word ..................................... 103 Multiple viewports....................... 408 Multiplying factor........................ 226 Multi-row editing......................... 327

Index N Natural frequencies ......230, 653, 655 New features ..................................15 Node loads ...................................207 Described .................................207 Graphics ...................................474 Text ..........................................265 Node numbering...........470, 638, 640 Node restraints .............129, 170, 423 Buckling analysis.....................681 Described .................................170 Elastic restraint ........................170 Frame data ...............................170 General restraint.......................170 Graphics ...................................423 Restraint code ..........................170 Text ..........................................259 Nodes ...........................................129 Described .........................129, 152 Graphics ...................................410 Text ..........................................255 Non-linear analysis .....129, 617, 618, 622, 623, 626, 629, 641 Normal members..........................154 Normal window ...........................369 Normalize mode shapes ...............655 Notes ............................................600 O Ocean currents .....................247, 516 Offsets ..........................................205 See member offsets..................205 See plates .................................162 Opening a job.................................80 Operating plane............................395 Optimization617, 632, 638, 639, 640, 641 Ortho ....................................382, 391 Output ..........................................690 Buckling analysis.....................690 Concrete column design...........863

Described................................. 867 Dynamic frequency analysis.... 663 Dynamic response analysis...... 672 Fonts .......................................... 37 Page setup................................ 873 Print graphics........................... 882 Print preview ........................... 878 Print text report........................ 881 Printing to a file ............... 873, 878 Scale ................................ 873, 882 Static analysis .......................... 652 Status report............................. 883 Steel connection design ........... 845 Steel member design................ 774 Text format ................................ 37 Worked examples .... 903, 961, 995 P Page setup .................................... 873 Pan ............................................... 582 Paradise solver ............. 641, 655, 684 Partial restraint............................. 733 P-delta effects ...... 622, 623, 629, 641 PDF file................................ 873, 878 Pick ........................................ 74, 369 Picture file.................................... 873 Page setup................................ 873 Print preview ........................... 878 Pitch ............................................. 817 Plane .................................... 340, 395 Plate pressure loads ..................... 222 Described................................. 222 Graphics................... 495, 540, 561 Text.......................................... 272 Plates............................................ 469 Align plate axes ....................... 469 Contours .................................. 562 Datasheet ................................. 327 Described................. 129, 137, 162 Drawing ................................... 431 Graphics........................... 419, 562

949

SPACE GASS 12 User Manual Library .............................885, 898 Meshing ...................................451 Moments for reinforced concrete slabs .....................................137 Pressure loads ..........222, 495, 540 Reverse plate direction.............467 Steel connection design ..815, 817, 835, 885, 898 Stress........................................562 Text ..........................................258 Wood-Armer method...............137 Point ...............................................74 Pointer............................................74 Poisson's ratio ..............................194 Polar coordinates..................397, 399 Portal frame builder .....................295 Prescribed node displacements ....209 Described .................................209 Graphics ...........................477, 561 Text ..........................................266 Pressure ........................................222 See area loads...........................511 See plate pressure.....222, 495, 540 Prestress .......................................220 See member prestress loads .....220 Pre-tension ...................................218 Principal angle .............................175 Print preview................................878 See output ................................867 Printing.........................................867 See output ................................867 Problem size limits.........................47 Program Manager...........................32 Property panels.............................402 ProSteel ........................101, 103, 106 Purlins ..........................................298 Q Query Analysis results ........................576 Member properties...................414

950

Node properties ....................... 410 R Radio buttons................................. 77 Rational buckling analysis........... 675 See buckling analysis .............. 675 Reactions ..................................... 620 Described................................. 620 Diagrams.................................. 561 Sign convention ....................... 137 Real-time ..................................... 595 Redraw......................................... 579 Region.......................................... 311 Registering SPACE GASS ...... 32, 60 Reinforcement ..... 137, 852, 885, 900 Relative coordinates............. 397, 399 Removing crossed member nodes459 Removing intermediate nodes ..... 458 Renderer... 48, 53, 340, 382, 402, 562 Renumbering ............................... 548 Load cases ............................... 548 Members .................................. 470 Nodes....................................... 470 Repeat last command................... 616 Reports......................................... 867 See output ................................ 867 Residual loading .......................... 641 Restraints ..................................... 170 See node restraints ................... 170 Results ......................................... 690 Buckling analysis..................... 690 Concrete column design .......... 863 Dynamic frequency analysis.... 663 Dynamic response analysis...... 672 Static analysis .......................... 652 Steel connection design ........... 845 Steel member design................ 774 Reverse member direction ........... 466 Reverse plate direction ................ 467 Revit Structure..... 101, 103, 106, 118 Right hand orthogonal ................. 130

Index Right hand screw rule ..................137 Rigid diaphram.............................196 Rigid offset ..................................205 Risa-3D ........................................103 ROBOT ........................................103 Rotate ...........................................437 Rotational inertia..........................230 Rotational restraint.......................733 S SAP2000 ......................................103 Saving a job ...................................80 Scale.............................................445 Scales ...........................................584 Scissor lift ....................................196 Scripts ............................................91 Scroll bars ......................................77 Scrolling.........................................96 SDNF file .............................101, 103 Sea loads ..............................247, 516 Seats .............................815, 817, 835 Secant matrix ...............................641 Section check ...............................774 Section properties.........129, 154, 424 Angle sections..................175, 192 Area of section .........................175 Described .................................175 Flipping a section.............175, 190 Graphics ...................................424 Library .............................885, 894 Map file....................................106 Moment of inertia ....................175 Principal angle .........................175 Section mark ............................175 Shape builder ...........................180 Shear area.................................175 Source ......................................175 Tee sections..............................191 Text ..........................................260 Torsion constant.......................175 Security ..........................................14

See Hardware lock............... 14, 31 Selecting nodes and members...... 369 Selection window ........................ 369 Self mass.............................. 230, 655 Self weight................................... 224 Described................................. 224 Graphics........................... 498, 561 Text.......................................... 273 Sentinel protection installer ........... 32 Serviceability check..................... 755 SG file............................................ 80 SG.INI............................................ 33 Shading .......................................... 39 Shape builder ............... 175, 180, 414 Shear area .................................... 175 Shear check.................................. 774 Shear forces ................................. 620 Described................................. 620 Diagrams.................................. 561 Sign convention ....................... 137 Shear wall .................................... 196 Shielding...................................... 311 Shortcuts ........................................ 96 Sidesway...................................... 713 Sign conventions.......................... 137 Analysis ................................... 137 Bending moment diagrams........ 39 Concrete column design .......... 852 Steel member design................ 726 Sign of the results ........................ 666 Site factor..................................... 666 Site subsoil category .................... 666 Skew angle................................... 154 See direction angle .......... 154, 162 Slave node.................................... 196 Slenderness ratio.......................... 743 SmartPlant4D............................... 103 Snap ..................................... 340, 389 Solvers Paradise.................... 641, 655, 684 Watcom.................... 641, 655, 684 Wavefront ................ 641, 655, 684

951

SPACE GASS 12 User Manual Sound .............................................39 Spectral loads ...............................233 Described .................................233 Editor .......................................237 Library .............................885, 901 Spectral curve multiplier..........666 Text ..........................................277 Spring stiffness.............................170 SRSS ............................................666 STAAD ........................................103 Stability analysis ..........................675 See buckling analysis...............675 Stabilizing nodes..................144, 641 Standard shapes............................414 Starting SPACE GASS ..................64 Static analysis...............617, 618, 641 Analysis type............................641 Buckling...................................631 Buckling messages...................641 Compression-only members ....641 Damping ..........................626, 641 Errors .......................................692 Iterations per load step .............641 Load cases................................641 Load stepping...................626, 641 Non-linear effects ....................641 Optimization ............................641 Results......................652, 931, 946 Tension-only members ............641 Worked example ......................903 Static load to mass conversion .....508 Status line.......................................71 Status report ...........................95, 883 Steel connection design................815 Described .................................815 Designing and checking...........835 Drawings..........................817, 835 Exporting .........................817, 835 Importing .................................835 Input.........................................817 Load cases........................817, 835 Minimum design actions..817, 835

952

Preferences .............................. 848 Reports..................................... 845 Steel member design.................... 757 Check mode ............................. 757 Combined stress ratio .............. 743 Described......................... 707, 713 Design mode.................... 743, 757 Effective lengths.............. 678, 713 Errors ....................................... 811 Flange restraints....................... 733 Grouping.................. 713, 727, 758 Input......... 699, 701, 707, 710, 712 Load cases ............................... 743 Load factor............................... 743 Member check ......................... 774 Results ............................. 774, 969 Section check........................... 774 Shear check.............................. 774 Sign convention ....................... 726 Tee sections ............................. 742 Text.......................................... 278 Worked example...................... 961 Step file........................ 101, 103, 106 CIMSteel/2 file ........ 101, 103, 106 IFC file..................... 101, 103, 106 Stiffeners...................... 815, 817, 835 Stiffness matrix... 129, 144, 638, 640, 641, 655 Strength grade.............................. 713 Stress ratio ................................... 743 Stresses ................................ 561, 562 Members .................................. 561 Plates........................................ 562 Stretch.......................................... 443 StruCAD ...................... 101, 103, 106 Structure wizard........................... 291 Sub load number .......... 211, 213, 216 Subdivide ..................................... 449 Subsets ......................................... 590 See filters ................................. 590 Supports ....................................... 170 See node restraints ................... 170

Index T Tangent matrix .............................641 Tapered Members ........................463 Tee sections..................191, 742, 894 Tekla Structures ...........101, 103, 106 Temperature change.....................218 Tension-only and compression-only effects.......................................624 Tension-only members154, 624, 626, 641, 655 Terminator ...................................281 Terrain category ...........................311 Text boxes......................................77 Text display area ............................68 Text editor....................................251 Text file........................................282 Errors .......................................282 Exporting .................................251 Format................................37, 252 Importing .................................251 Worked example ......................287 Text reports ..................................867 See output ................................867 Textures .......................................611 Thermal loads...............................218 Described .................................218 Graphics ...........................489, 561 Text ..........................................270 Title bar..........................................68 Toolbars .........................................68 Customizing ...............................53 Top flange ....................................707 Topography ..................................311 Torsion constant...........................175 Torsions .......................................620 Described .................................620 Diagrams..................................561 Sign convention .......................137 Translational inertia .....................230 Transparency................................613 Trapezoidal loads .........................213

Triangular loads ........................... 213 U Units............... 39, 148, 253, 852, 894 Unstable equilibrium ................... 631 Updating frame member sizes ..... 753 Using the keyboard to position points ................................................. 399 Using the mouse ............................ 74 Utilization ratio............................ 817 V Varying plate pressure loads........ 540 Vehicle library ..................... 526, 902 Vertical angle............................... 595 Vertical axis........................... 39, 595 Vertical direction ......................... 666 View............................................. 561 Diagrams.................................. 561 Member properties................... 551 Members .................................. 550 Node properties ....................... 551 Nodes....................................... 550 Plate contours .......................... 562 Steel connection drawings ....... 817 View manager.............................. 599 View results ................................. 867 See output ................................ 867 View results in XY or XZ plane .. 560 View selector ............................... 595 Viewpoint .................................... 595 Viewports..................................... 408 Views ..................................... 96, 593 Voids............................................ 852 Von Mises Stress ......................... 137 W Watcom solver ............. 641, 655, 684 Wave loads .......................... 247, 516 Wavefront optimizer.... 617, 632, 641

953

SPACE GASS 12 User Manual Analysis method ......................638 Analysis method in more detail640 Calculating the frontwidth .......639 Wavefront solver..........641, 655, 684 Welcome to SPACE GASS .............1 Welds ...........815, 817, 835, 885, 899 Wind loads ...................................311 Windows ........................................80 Wood-Armer Method...................137 Worked examples.........................955 Bill of materials .......................955 Buckling analysis.....................959 Cable analysis ..................995, 999 Centre of gravity ......................955 Dynamic frequency analysis ....956 Dynamic response analysis ......957 Frame analysis graphics...........914 Frame analysis input ................920 Frame analysis output ......931, 946 Portal frame analysis................903

954

Portal frame connection design971 Portal frame member design.... 961 Steel connection design ........... 815 Steel connection drawings ....... 817 Steel member design................ 969 Working plane ..................... 340, 395 X XLS file ....................................... 101 See MS-Excel .................. 101, 103 XSteel .......................... 101, 103, 106 Y Young's modulus ......................... 194 Z ZIP file......................................... 103 Zoom............................................ 580

SPACE GASS 12 Manual

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