ETABS Learning Guide

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CATHOLIC UNIVERSITY OF NORTH SCHOOL OF ARCHITECTURE, CIVIL CONSTRUCTION AND ENGINEERING DEPARTMENT OF CIVIL ENGINEERING

Development of a multimedia learning environment for learning the structure area in the careers of the Faculty of Architecture, Construction and Civil Engineering

AUTHOR: JUAN MUSIC Tomičić

DATE: MARCH 2005 E-Mail: [email protected] ail: [email protected]

Juan Music Tomicic - Department of Civil Engineering - Catholic University of the North

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Development Development of a multimedia learning environment for learning the structure area in the careers of the Faculty of Architecture, Construction and Civil Engineering

Summary In the Department of Civil Engineering at the Catholic University of the North, we have incorporated various software for the design of structures. Among them we can mention the ETABS, SAP and SAFE. The classes give students the theoretical and practical, for the management of new design tools and their application to new technologies and current market trends knowledge. To achieve this goal, we set out to develop learning environments based on multimedia technologies, aportasen a number of positive elements, from a pedagogical point of view, the assimilation of knowledge necessary for the student to work proficiently within and commented design tools. As part of this work, we have prepared prepared these notes and added material material developed, developed, which is delivered on a CD, to facilitate student learning in the area of structure. Here is exposed in a clear and concise manner, how to use the ETABS and SAP software. It is important to note that to use software properly prerequisite is mastering the theory in which the program is based. Without it, it is neither possible nor advisable to use any program.


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Development Development of a multimedia learning environment for learning the structure area in the careers of the Faculty of Architecture, Construction and Civil Engineering 1) Introduction The approach to teaching structural analysis is changing rapidly due to the profusion of use and availability of the computer. The ever lower costs and ever increasing computing capacity have had, as expected, a positive effect on structural analysis programs. The number and variety of programs for the analysis and design of structures has grown at the same pace as computers have been developed. It is very likely that one or even several programs such as SAP2000, ETABS, Visual Analysis, STAAD / Pro, RISA, GT-Strudl, Robot, Cypecad and others, are today in all offices calculation and design. In tune with the times, the group of teachers in the area Structure of the Department of Civil Engineering at the Catholic University of the North, has implemented and continues to consider changes in the content of their courses of analysis and design. In particular, it is putting more emphasis on analysis of undergraduate courses in the stiffness matrix method. Technological changes in education in general and in structural engineering are inevitable and irreversible and makes no sense to oppose them; on the contrary we should accept and adopt them judiciously and intelligent. Current students were born and grown up immersed in the age of computers and generally feel very comfortable with the use of computers. It is therefore logical and reasonable to exploit these opportunities to improve their technique. Mentioned it before, but provides us with a powerful tool, it is important to reflect on the use (and abuse) of structural analysis programs. As opportunity to appreciate later be taken, it is possible for a user to create a model of a relatively complicated structure and analyze for different load conditions very easily and with minimal knowledge of the subject. However, this can have very negative and even catastrophic consequences. Like any professional or experienced teacher knows, it is impossible (and dangerous) to replace the expertise and years of study with a computer. It is well known English adage "garbage-in, garbage-out". In other words, the results delivering a computer program are as bad (or good ...) as data is entered. Using the computer to optimize the design to be feasible to consider various structural systems, geometry or sections for the same structure in a reasonable time. You can also increase the structural reliability to power relatively easily considered various scenarios or combinations of loads beyond the minimum required by code. The same goal is achieved by the analytical model closer to the actual structure making it more sophisticated and detailed (eg considering dimensional effects, etc.). By reducing the


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time for analysis and design, efficiency and hence the competitiveness of an engineering company is benefiting. All this is possible through the use of professional programs for structural analysis. What can not be replaced by a computer is the effort behind years of study and good engineering judgment. Therefore, our basic philosophy in teaching art and science of structural engineering has not changed. All students must learn and understand clearly the assumptions and simplifications are made to create a model, or method of calculation. Must be able to play hand what the computer can do to a simple structure, including the famous diagrams of internal forces and moments. Must be able to determine if the test results, either by hand or machine, make sense or not. Methodology should know and be able to calculate the loads (dead, live, wind, earthquake, etc.) for analysis of the structure. You should know the differences between the various structural systems and how they work. Only once you have mastered these aspects (and maybe one other not cited), the student or professional is trained to use successfully and productively as powerful a tool as a structural analysis program. Therefore, if the programs are used by people who have solid knowledge of the conceptual foundations of the methods used and their assumptions and apply their experience and good structural criteria, these are a good tool support engineer. In the Department of Civil Engineering at the Catholic University of the North, we have incorporated various software for the design of structures. Among them we can mention the ETABS, SAP and SAFE. The classes give students the theoretical and practical, for the management of new design tools and their application to new technologies and current market trends knowledge. To achieve this goal, we set out to develop learning environments based on multimedia technologies, aportasen a number of positive elements, from a pedagogical point of view, the assimilation of knowledge necessary for the student to work proficiently within and commented design tools. As part of this work, we have prepared these notes and added material developed, which is delivered on a CD, to facilitate student learning in the area of structure. Here is exposed in a clear and concise manner, how to use the ETABS and SAP software. It is important to note that to use software properly prerequisite is mastering the theory in which the program is based. Without it, it is neither possible nor advisable to use any program.

2) Practical Manual for using the ETABS program Exposed, then the main aspects to learn and master the use of ETABS program.


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a) General Aspects ETABS is a program of structural analysis and design based on the finite element method, with special features for analysis and structural design of buildings. The numerical methods used in the program design procedures and international design codes allow you to be versatile and productive, whether it is designing a twodimensional gantry or performing a dynamic analysis of a high-rise building at the base insulator. b) Fundamental Concept ETABS works within an integrated data system. The basic concept is that you create a model system consisting of flat and vertical systems and side porch (or wall system) to analyze and design the entire building. All that is needed is to integrate the model into a versatile system analysis and design with an interface. No external maintenance modules and not worry about data transfer between modules. The effects on a part of the structure due to changes elsewhere are instantaneous and automatic. c) Variety of Options Analysis The analysis methods include a variety of options for static and dynamic analysis. The integrated model can include systems, steel beams, resisting frames, complex systems of shear walls, slabs of rigid and flexible floor, sloping roofs, ramps and parking structures, trusses systems, multiple buildings and systems staggered diaphragm.

d) Numerical Methods The numerical methods used to analyze the building floor systems allow modeling of steel deck and concrete slab that can automatically transmit their loads to the main girders. The finite element meshing automatically made of a complex system of floor displacement interpolated transitions meshes different characteristics associated with Ritz vector analysis for dynamic analysis, allows for the inclusion of the effect of flexibility of the diaphragm in the analysis in a practical way. The options allow dynamic vertical analysis include the effects of the components of the vertical ground motion in its seismic analysis. This will also allow a detailed evaluation of vertical vibration problems, in addition to the traditional empirical methods are also included within the software floors. The special problems associated with the construction of typical structures have been associated with allowing customized easily include their effects on numerical analysis techniques. The special problems including, among others, are: Calculating the center of rigidity, local and global P-Delta effects, including panels isolated on deformable zone, effect of rigid joints at the ends and


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displacement ends of elements relative to the cardinal points of a section. e) Advanced Capabilities More advanced options include sophisticated numerical methods for modeling nonlinear damping, pushover analysis, based insulation, construction sequential load, impact and structural survey. f) Using the Manual Developed The manual that comes introduces the use of the program ETABS Version 8.4.5. ETABS is an extremely versatile and powerful program with many features and benefits. This manual is not intended as a document that covers a whole these features and benefits. He was drafted thinking you want to do structural analysis of a multistory building, which has rigid diaphragm at floor level and a seismic analysis be undertaken by the dynamic method of spectral modal superposition, according to the provisions of the Nch433of96 standard. To capture the full value of ETABS, this manual should be used in conjunction with other program documents, such as the reference manual-use graphical interface and design manuals steel, concrete shear walls and floors section composed. It is important to note finally that the program includes lots of online help is available whenever the graphical interface is open. The documentation is available in two forms: a standard helps the Windows style and a document library. You access the Windows style help by clicking the Help menu and selecting Search for Help on ...., Or by pressing the F1 function key on the keyboard. If the F1 key is pressed while a form is open, help related to that item will be displayed. Windows style aid provides guidance regarding data entry into various forms used in the program. Often also clarify the meaning of the data entered into the forms. The document library is a set of .pdf files that can be viewed or printed using Adobe Acrobat Reader. You access the document library using the Help> Documentation and Tutorials command, which present the ETABS Documentation form. This form displays several of the categories of documentation available. Doing Double click (left mouse button) on the name of a category will present a list of individual documents available in .pdf format. Note that some categories also have subcategories. Double clicking on the right mouse button on the name of an individual document presented summary information about content, size and date. Double-click (left mouse button) on behalf of an individual document, or highlighting it and clicking the button Display Selected Document will run the Adobe Acrobat Reader and display the selected document. Note that many files contain hyperlinks for easy navigation between documents.


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MANUAL OF USE ETABS PROGRAM.

1. General Considerations •

•

•

•

Are presented the Main commands the ETABS program, version 8.4.5. The building is supposed to analyze features rigid diaphragm at floor level. The provisions of the Nch standard apply. 433 Of. 96. A seismic analysis will be performed by the method of overlapping spectral mode.


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2. Steps to perform a structural analysis of a building with Etabs Software V8. diissttiinngguuiisshh 6ssttaaggeess M Maaiinn:: Ar e ccaann d

• Step 1: Structuring the building. • Step 2: Creating the structural model. • Step 3: Perform Modal Analysis. • Step 4: Defining and analyzing seismic loads states. • Step 5: Perform structural analysis. • Step 6: Viewing results.

STEP 1: Structuring the building. It is the most important stage and is to define the location, dimensions and materials of all structural elements to adequately withstand the loads acting on the building, according to provisions of Chilean standards. For proper structuring, requires: • Mastery of the fundamentals of a good structure; • Practical experience of the engineer.


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Before using the program must: i) Define the structure of the building; ii) Set the global coordinate system (X, Y, Z); iii) Define the axes required to locate the resistant elements (Beams, columns, walls, slabs, etc.) building.

Upon completion, you must open the ETABS program, which brings us to the main screen of it, which is shown in the figure below, where we choose the unit system (these can be changed later).

Main. Point and assign joint.

Frame assign line. Shell and assign area.

Display Define.

Design.

Draw.

Select.

Coordinate System.

Option Allocation By levels.

Work Units.

Snap.

Etabs Software Main Window.


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A 2 ETAP: Creation of the structural model. • S t e p 1 : Create new file and save as job file. File → New Model /

FFiillee →S Saavvee ace //

.

.

• S t e p 2 : Edit the grid. Edit → Edit → Edit grid data grid /

.


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Form Editor Grids.

• S t e p 3 : Edit floors or levels. Edit → Edit → Edit story dating story /

.

C

B

A


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A Form Level Editor.

B Form Insert new levels.

C Form Remove levels.


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• S t e p 4 : Definition of materials. Define → Material Properties /

.

• Step 5D efine sections beams, columns and diagonals. Define → Frame sections /

.


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The armor reinforcement specified shall be verified by the program. The reinforcement shall be determined by the program. It is necessary to define bars.

• S t e p 6 : Define sections of walls and slabs. → Define Wall / Slab / Deck sections /

.


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• S t e p 7 : Draw and assign walls (Surface elements). Generate walls from the plan view or elevation, defining start node and end node.

Generate walls from the plan view or elevation, with a single click on the line of the grid.

• S t e p 8 : Draw and assign columns, beams and diagonal (Line items).

This button lets you draw a beam or column between the points where you clicked.

This button lets you draw a beam or column in a particular region on the grid.

This button lets you draw a column in the grid intersection.


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Insertion Point Command

•

To determine if a beam is normal, inverted or semi-inverted (by default, the beam is centered on the level of the floor), it must be selected once you have been assigned and then proceed as follows:

Assign → Frame / Line → Insertion point.

This window modifies the location of the beam relative to the global axes (X, Y, Z) or local (1, 2, 3).

• Step 9 :Draw and assign slabs (Surface elements).

Draw Areas (Plan, Elev, 3D).

Draw Rectangular Areas (Plan, Elev).

Draw Areas with a click (Plan, Elev).


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• S t e p 1 0 : Meshing of slabs and walls OPTION 1 : Manual Case.

Edit → Mesh Areas

Option helpful.

•

OPTION 2: Automatic Case. Assign → Shell / Area → Area Object Mesh Options


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• S t e p 1 1 : Ensure connectivity in all elements Assign → Shell / Area → Auto Line Constraint.

• S t e p 1 2 : Assign rigid diaphragms You must select the slab, then:

Assign → Shell / Area → Rigid diafragm /

.

If the structure has only one floor diaphragm on each level, it is convenient to identify them all with the same name (eg. Diafrag.). This is easy to determine the cumulative mass floor to floor to see the results of the analysis.


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• S t e p 1 3 : Allocating in the base support Points → → Assign Joint Restraints (Supports) /

.

STAGE 3: Perform Modal Analysis. The goal is to find the periods associated with increased translational mass in both X and Y, ie, finding Tx and Ty * * directions, to determine the spectrum of design as standard Nch. 433 Of. 96.


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• S t e p 1 4 : Define the types of loads → Define Static Load Cases /

.

PP = Dead Weight. SC = overload. TERM = Terminations.

• S t e p 1 5 : Assignment of gravitational loads on slabs i) Select slabs; ii) Selecting appropriate option allowance levels.

Assign → Shell / Area Loads → Uniform /

.


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The program comes with a built-in calculator, which has a set of functions that are useful for assigning loads. This may be obtained by keeping the Shift key and double click on the Load field.

• S t e p 1 6 : Definition of mass to be considered in the seismic analysis → Define Mass Source /

.

Recommended option.

By specifying the masses through the assigned loads, it is necessary to define what percentage of these charges should be considered in determining the seismic mass, according to the provisions of Nch433 Of.96.

Prevents vibration modes of vibrations are generated outside the plane of the diaphragms (vertical).


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• S t e p 1 7 : Run Modal Analysis Analyze → Set Analysis Options. The number of modes to be considered must be sufficient to accumulate at least 90% of the seismic mass in each direction of analysis (Nch433 Of.96).

• Step 18 :

Look For period associated to higher translational mass (Tx and Ty * *), verifying that amount of vibration modes is considered adequate. Display → Set Output Table Mode /

.

Selecting Freight charges or states.


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Ty *

Tx *

Accumulated more than 90% of the mass analysis in each direction.

Form deployment periods and equivalent masses associated with each mode of vibration.

A 4 ETAPDefinition of Quake to analyze and United Cargo. •

:Define the acceleration spectrum Step 19 Define → Responce Spectrum Functions /

.

A B

There are two ways to incorporate design spectrum to the program, which are explained below:


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A) From Text File.

B) Income Manual.


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• S t e p 2 0 : Definition of earthquakes Define → analyze Responce Spectrum Cases /

.


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• S t e p 2 1 : Consideration of accidental torsion You can enter in 2 ways: i)

Transversely moving the location of the centers of mass of the model b ± 0.05 * kyTo the quake X direction and ± 0.05 * bkx for earthquake Y direction

Earthquake acting with an eccentricity of 5%.

ii) Applying twisting moments at each level static, calculated as the product of the combined effort variation cut at that level by an accidental eccentricity, given by:

Bky ± 0.1 * * Zk / H for the quake as X BKX ± 0.1 * * Zk / H for the quake as Y.


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Entry form accidental torsion moments Mz.


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• S t e p 2 2 : Definition States Define Loads → Load Combinations /

.

Step 5:Perform Structural Analysis. •

Step 23 :Check Model Analyze → Check Model.


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• S t e p 2 4 : Define type of analysis Analyze → Set Analysis Options.

• S t e p 2 5 : Structural Analysis Analyze Run → Run Analysis /

.

Choose any of the two options.


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STAGE 6:Display results. The analysis results can be viewed therefore screen as via database generated by the program.

• S t e p 2 6 : Display results screen Display → Set Output Table Mode /

.

As an example, you can display the floor cuts generated by the spectra for each of the directions of analysis, as shown in the following figure:


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Viewing the seismic weight.

Location of the centers of mass and stiffness centers of each level.


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• Step 27 :Display results through a database generated. To this must go to the Microsoft Access program and open the file that was created in step 24.

Options mo st used.

As an example, you can display the floor cuts generated by the spectra for each of the directions of analysis, through an Access database in a pivot table, as shown in the following figure:


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Design of Reinforced Concrete Walls.


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D tth D g n h b w n Deeesssiiig gn n t heee Wall M M20 aaaxxxiiisss Oneb beeetttw weeeeeen n A-B o p r o d Through the T Thr eemethods w what p pr r ovvviiid deeesss Etabs

tth o d g n h Methodology B Basic ttto o thed deeesssiiig gn n t heee w a l l

1) Go to Option menu> Preferences> Shear Wall Design and then define the design code with their respective output units

Amounts design


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2)

Select the wall full model M20.

3)

Go to the Assign menu> Shell Area> Pier Label and add an identifying name Pier

4)

Go to the View Options menu in September Building and Pier Labels enabled, disabling the other options identification labels to visually verify the name assigned to the Pier.

W tthhheee e eennnddd of check tthe aaalllo W Wiititthhh t loocccaaatttiio ioonnn the Pier , this is convenient aaaccctttiivivvaaattteee the oooppptttiio ioonnn off view (Pier label) anddeactivate ttthhheee other O O Oppptttiio ioonnnsss of view in the same column

View iin elevation ttthhheee aaaxxxiisiss One


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5)

Go to the Design menu> Shear Wall Design> Select Design Combo and then add the defined load combinations for design, removing the combinations generated by default.

6)

Go to the Design menu> Shear W all Design> View / Check pier Overwrites to

activate the seismic design with the provisions of Chapter 21 of the ACI318-99

6)

There are 3 methods for the design of walls: a) Tension-compression: Only the pillars edge designs, determining the length edge of Pier and flexural reinforcement edge, also designs the entire section cut. The design is based on efforts of a two-dimensional plane. b) Armor evenly distributed : Flexural and shear design for the entire section. It also allows comparing the longitudinal reinforcement given by the user with the calculated by the program. The design is based on the interaction dimensional diagram. c) Armor General: flexural and shear design for the entire section. You can create different sections with irregular armor. It also allows comparing the armor given by the user with the calculated by the program. The design is based on the diagram is three dimensional interaction. * For the last two cases you can check Demand v / s Capacity section where this factor is an indicator of the wall stress conditions with respect to their ability, based on threedimensional diagram interaction. *


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6.1)

Tension - compress ion:

Select the entire wall or the desired section, then go to the Design menu> Shear Wall Design> Assign Pier sections for Checking> Simplified C and T section

ttt D C u eeetto S r D g n Ch h o f S r u uur r Run S Stttaaar r Deeesssiiig gn n / / / C heeeccckkk o of f S Stttr r uccctttu r too dddeeesssiig tthhheee wa ll iggnnn t eexxxeeecccuuutte whhhaaattt ar e bbbeeeeeeccchhh e Af teeddd ttthhheeeaaannnaaally lyysssiisiss Af ter w r w ttthhheee model.

V tthhheee wa ll w oof f f d ddeeesssiig V w Viie ieew w t with tthetttyyypppeee o iggnnn aaassssssiig iggnnneeeddd (C // T T)

V tthhheee wa ll d m V w r m r Viie ieew w t designed w with tthe aaar r mooor r pr oposal, then eeexxxeeecccuuuttteeeddd thedddeeesssiig n t h e iggnn tthhee wall

off


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W W w Wiin inndddooow w ooof f f dddeeesssiig iggnnn tttooo Te ns io n -Compr ession, wher e ar e sample the oof f f d ddeeesssiig f f lle aaalll and w r combination o of l oad w whhhaaattt contr ols tto too the Febr uar ytttyyypppeee o iggnnn::: f leexxxuuur r w h a t d o n o t o f i w h a t d o n o t o f court. (Is appr eciated what d o n ot places r estr iction of ar mor m inima in inn the design of t f tthhheee pillar s).

666...222))) Strengthening uniform : eeeddd,,, then g tthhheee m m S D meeennnuuu D D g n Sh h r W Deeesssiiig g n Select tthe w wa ll f f ull o or the s section dddeeesssiir ir r go tttooo t Deeesssiiig gn n>>> S heeeaaar r W Waaallllll D gn n>>> A s s i g n P i e r s e c t i o n s U n i f o r R e i n f o r c i n g P i e r S e c t i o n A Piieer Reeiin Piieer Seeccttiio Assssiig gn n P r sseeccttiio on nss f or Checking > >U Un niif f o or r R nf f o or r cciin ng g P r S on n

ttt D C u eee S r D g n Ch h o f S r u uur r Run S Stttaaar r Deeesssiiig gn n / / / C heeeccckkk o of f S Stttr r uccctttu r tttooo d ddeeesssiig tthhheee wal l iggnnn t eexxxeeecccuuutte whhhaaattt ar e bbbeeeeeeccchhh e Af teeddd ttthhheeeaaannnaaally lyysssiisiss Af ter w r w ttthhheee model.


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For the uniform reinforcement, only to define the type of distributed armor longitudinal sides and bars in the corners

φ 8 @ 25 (unif) φ 12 (corners)

View of reinforcement placed on the wall when she gets defined as strengthening uniform

Required Reif Ratio: Current REINF design Amount Ratio: Amount Provided.

ooor m w eee ar e s r m whhheeer r Window o of designtttooo r einf or cement uuunnniif if f r m w r s ample tthe combination w h a t t o t y p e o f d e s i g n : f l e x aaalll and court. of f d deessiiggnn:: f f lleexxuuur r of load w whhaatt contr ols ttoo the F Febr uar yttyyppee o r


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6.3) Strengthening General: D iiin aadddddd a aannnssseeeccctttiio Waaalllll> Deeef f n Go tto tthe m menu Design> S Shear W l>> D f neee Pier f or Checking,tttooo a ioonnn to r W r ooom aannn P P r m Piie r be ""Checked"f f f r m a ieer r Existing

Of the previous figure, Section Designer enabled to change the default placed armor and permit comparison between the design v / s or placed by the ability of the armor section.


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eeeddd,,, then go tttooo ttthhheee m m D g S h r W Select the wal l f ull or the section dddeeesssiir ir r meeennnuuu D Deeesssiiig gnn n>>> S Sh heeeaaar r W Waaallllll D A P o ccceeem D g n Assssssiiig g n Piie r Seeeccctttiiio o n R n f o r m n P r S oon n Deeesssiiig gn n>>> A gn n P ieer r S S on nsss f or Checking > >Gener al R Reeeiiin nf f or r meeen nttt P Piiieeer r S Seeeccctttiiio n

ttt D C u eee S r D g n Ch h o f S r u uur r Run S Stttaaar r Deeesssiiig gn n / / / C heeeccckkk o of f S Stttr r uccctttu r tttooo d ddeeesssiig n t h e iggnn tthhee wal l eexxxeeecccuuutte whhhaaattt ar e bbbeeeeeeccchhh e Af teeddd ttthhheeeaaannnaaally lyysssiisiss Af ter w r w ttthhheee model.

T iin aaalllylyy aaappppppeeeaaar sss aaannn window w T r r w Thhheeennn ooof f f dddeeef f f inneee ttthhheee type ooof f f section gggeeennneeer r r whhhaaattt indicates ttthhheee lleeevvveeelll top a iin r einf or cement w what ttake ttthhheee l andlower t also a ar e cccooouuulld ldd havedddeeef f f inniititteee r tthhheee wall. ((You a g e n e r a l t h e e n d o f i n t h e enndd o of f decr ease tthe r other section ggeenneer r aall with tthhee e r einf or cement iinn the h height tthhee wall)

(D): Design

V oof f f the aaalllo tthhheee wa ll w aaalll V w r Viie ieew w o loocccaaatttiio ioonnn t with r r einf or cementgggeeennneeer r


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Required Reif Ratio: Current REINF design Amount Ratio: Amount Provided.

W eee ar e s amp le the W w w r Wiin inndddooow w of dddeeesssiig iggnnn tttooo r einf or cement Gener al, w whhheeer r ddeeesssiig f f lle aaalll and w r combination o of load w whhhaaattt contr ols tto too the F Febr uar ytttyyypppeee ooof f f d iggnnn::: f leexxxuuur r cccooouuur t . r r tt..

W W w C U D C Wiin inndddooow w ooof f f C Chhheeeccckkk U Uppp to r einf or cement Gener al, wher e ttthhheee r adio D D /// C C t o t h e p e r c e n t a g e o f D e m a n d t h i s o n e t o t h e p e r c e n t a g e o f D e m a n d t h i s o n e cor r s C Capacity, w wher e this one f actor re sponds to t he p er centage of D emand v // s ttthhhiisiss i iisss aaannn indicator o f f o ttt the w r r of e f oor wall w with r r espect ttohis capacity. r oof f f the tter ms o f eef f f


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3) Practical Manual Using the SAP Program Exposed, then the main aspects to learn and master the use of SAP.

MANUAL OF USE SAP2000 PROGRAM.


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1. General Considerations • Are presented the Main commands the SAP2000 software, version 8.3.3. • The building is supposed to analyze features rigid diaphragm at floor level. • The provisions of the Nch standard apply. 433 Of. 96. • A seismic analysis will be performed by the method of overlapping spectral mode.

2. Steps to perform a structural analysis of a building with SAP2000 software. diissttiinngguuiisshh 6ssttaaggeess M Maaiinn:: Ar e ccaann d

• Step 1: Structuring the building. • Step 2: Creating the structural model. • Step 3: Perform Modal Analysis. • Step 4: Defining and analyzing seismic loads states. • Step 5: Perform structural analysis. • Step 6: Viewing results.


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STEP 1: Structuring the building. It is the most important stage and is to define the location, dimensions and materials of all structural elements to adequately withstand the loads acting on the building, according to provisions of Chilean standards. For proper structuring, requires: • Mastery of the fundamentals of a good structure; • Practical experience of the engineer.

Before using the program must: i) Define the structure of the building; ii) Set the global coordinate system (X, Y, Z); iii) Define the necessary axes to locate the resistant elements (Beams, columns, walls, slabs, etc.) building.

Upon completion, you must open the SAP2000 program, which brings us to the main screen of it, which is shown in the figure below, where we choose the unit system (these can be changed later).


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Design. Main. Display Draw.

Select.

Coordinate System.

Snap.

Work Units.

Coordinates of the cursor.

Main Window Software SAP2000.

STAGE 2: Creation of the structural model. • S t e p 1 : Create new file and save as job file. File → New Model /

.

FFiillee →Save a ace //

.


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•

S t e p 2 : Edit the grid.

Edit → Edit grid data.

Form Editor Grids.


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• S t e p 3 : Definition of materials. Define → Material Properties /

.

• S t ep e p 4 Define efine sections beams, D columns and diagonals. Define → Frame / Cable Sections /

.


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The armor reinforcement specified shall be verified by the program. The reinforcement shall be determined by the program. It is necessary to define bars.

:Define sections of walls and slabs. • Step 5 Define → Area sections /

.


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• Step 6 :Draw and assign columns, beams and diagonal (Line items).

This button lets you draw a beam or column between the points where you clicked.

This button lets you draw a beam or column in a particular region on the grid.

Insertion Point Command •

To determine if a beam is normal, inverted or semi-inverted (by default, the beam is centered on the level of the floor), it must be selected once you have been assigned and then proceed as follows:

Assign → Frame / Cable Cable → Insertion point. point.

This window modifies the location of the beam relative to the global axes (X, Y, Z) or local (1, 2, 3).


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• Step 7 :Draw and assign slabs and walls

(Surface elements).

Draw Areas (Plan, Elev, 3D).

Draw Rectangular Areas (Plan, Elev).

Draw Areas with a click (Plan, Elev).

• Step 8 :Meshing of slabs and walls OPTION 1: Manual Case.

Edit → Mesh Areas /

.


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•

OPTION 2: Automatic Case. Assign → Area → Automatic Area Mesh

•

:Ensure connectivity in all elements Step 9 Assign → Area → Generate Edge Constraints.


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• Step 10 : Assign rigid diaphragms You must select the nodes that make up the slab, then:

Assign → → Joint Constraints.

• Step 11 : Assign pads to the base Assign → → Joint Restraints /

.


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• Step 12 :Define Define Groups → Groups /

.

• Step 13 :Define Sections of cuts. Define → Sections Cuts.


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• Step 14 : Assign the selected items to a defined group. This step is necessary for cuts per floor. For this you must select floor by floor and t hen assign it to a group as defined in step 13.

Assign → Assign to group /

.

STAGE 3: Perform Modal Analysis. The goal is to find the periods associated with increased translational mass in both X and Y, ie, finding Tx and Ty * * directions, to determine the spectrum of design as standard Nch. 433 Of. 96.


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•

Step 15 :Define the types of loads Sets → Load Cases /

.

PP = Dead Weight. SC = overload. TERM = Terminations.

• Step 16 : Assignment of gravitational loads on slabs i) Select slabs

Assign → Area Loads → Uniform (Shell) /

.


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• Step 17 :Definition of mass to be considered in the seismic analysis → Define Mass Source /

.

Recommended option.

By specifying the masses through the assigned loads, it is necessary to define what percentage of these charges should be considered in determining the seismic mass, according to the provisions of Nch433 Of.96.

• Step 18 :Run Modal Analysis Analyze → Set Analysis Options.


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• Step 19 :Number of modes to consider Define → Analysis Cases /

.


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• Step 20 :Running the analysis. Analyze → Run Analysis.

• Step 21 :

Look For period associated to higher translational mass (Tx and Ty * *), verifying that amount of vibration modes is considered adequate. Display → Show Results Analysis Tables /

.


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STAGE 4Definition of Quake to analyze and United Cargo. • Step 22 :Define the acceleration spectrum Define → Functions → Responce Spectrum /

There are two ways to incorporate the program design spectrum, which are explained below:

.

A

B

A) From Text File.


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B) Income Manual.

• Step 23 :Definition of earthquakes analyzed Sets → Analysis Cases /

.


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• Step 24 :Consideration of accidental torsion Applying twisting moments at each level static, calculated as the product of the combined effort variation cut at that level by an accidental eccentricity, given by:

Bk ± 0.1 * and * Zk / H for the quake as X Bk ± 0.1 * x * Zk / H for the quake as Y.


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Entry form accidental torsion moments Mz.


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• Step 25 :Definition Define Loads States → Combinations /

.

Step 5:Perform Structural Analysis. • Step 26 :Define type of analysis Analyze → Set Analysis Options.


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• Step 27 :Structural Analysis Analyze Run → Run Analysis /

.

STAGE 6:Display results. The analysis results can be viewed therefore screen as via database generated by the program.

• Step 28 :Display results per screen Display → Set Output Table Mode /

.


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As an example, you can display the floor cuts generated by the spectra for each of the directions of analysis, as shown in the following figure:



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• Step 29 :Display results through a database generated. To this must go to the Microsoft Access program and open the file that was created in step 24.

Options mo st used.


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As an example, you can display the floor cuts generated by the spectra for each of the directions of analysis, through an Access database in a pivot table, as shown in the following figure:



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ETABS Learning Guide

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