SCJ v46n2 Web Secured

Steel Construction . k r o w t e n r u o y m o r f d e t e l e d e . b d t e s t i u b i m h n o r o p i t a e c r i l a b n u o p t i s u i b h t i r , t I s i S d A d e n h t a e m g o r a r f o n t s g i , s e e r s u y k n r a o p w t m o e n c ; r y u p o o y c r d l e u p o a h p S . e d n e o t t i s u l m r p e y p l s n i o r k r t e o u w p t e m n o r c u r o u y o n y o o n t o g i n t i u v b a i r s t s s i d w o r l o l a e e g c a r n o e t c s i l , r e e s s u u : l I S a A n o e s r h t e f p o r u s r o e y : b I m S e A m e e h t t f a r o o s p r r o e c b l m a e i c m n l a a n u i F d i . i v t h d g i n i r y l a p i o c c n I a n S i A F

Journal of the Australian Steel Institute

3D 3D Volume 46 Number 2 – Marc March h 2014 2014

Structural Struc tural Steel Tubular Connection Series, 2014: Background and Summary

ISSN 0049-2205 PRINT POST APPROVED PP255003/01614

Interactive content featured in PDF version

. k r o w t e n r u o y m o r f d e t e l e d e . b d t e s t i u b i m h n o r o i p t a e c r i l a b n u o p t i s i u b h t i r , t I s i S d A d e n h t a e m g o a r r f o n t s g , i s e e r s u y k n r a o p w t m o e n c ; r y u p o o y c r d l e u p o a h p S . e d n o e t t i s u l m r p e y p l s n i o r k r e t o u w t p e m n o r c u r o y u o n y o o t n o g i n t i u v b a i r s t s s i d w r o l o l a e e g c a r n o e t c s i l , r e e s s u u : l I S a A n o e s r h t e f p o r u s r o e y : b I m S e A m e e h t t f a r o o s p r r o e c b l m a e i c m n l a a n u i F d . i v t i h d g i n i r y l a p i o c c n I a n S i A F

ASI CONT CONTAC ACT T DETAILS DETAILS Head Of fi c e

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Level 13, 99 Mo Moun untt St Strree eett

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North Sydn Sydney ey NSW 2060

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. k r o w t e n r u o y m o r f d e t e l e d e . b d t e s t i u b i m h n o r o i p t a e c r i l a b n u o p t i s i u b h t i r , t I s i S d A d e n h t a e m g o a r r f o n t s g , i s e e r s u y k n r a o p w t m o e n c ; r y u p o o y c r d l e u p o a h p S . e d n o e t t i s u l m r p e y p l s n i o r k r e t o u w t p e m n o r c u r o y u o n y o o t n o g i n t i u v b a i r s t s s i d w r o l o l a e e g c a r n o e t c s i l , r e e s s u u : l I S a A n o e s r h t e f p o r u s r o e y : b I m S e A m e e h t t f a r o o s p r r o e c b l m a e i c m n l a a n u i F d . i v t i h d g i n i r y l a p i o c c n I a n S i A F

ASI CONT CONTAC ACT T DETAILS DETAILS Head Of fi c e

Queensland & NT

Western We stern Australia

Level 13, 99 Mo Moun untt St Strree eett

Joh Jo hn Ga Gard rdne nerr – Sta tatte Ma Man nage gerr

Jame Ja mes s Eng ngla land nd – Sta tate te Ma Man nag age er

North Sydn Sydney ey NSW 2060

National Natio nal Edu Education cation Mana Manager ger – Techni echnical cal

Suite Suit e 1, 2a Brod Brodie ie Hall Drive

PO Box 6366

Brisbane Technology Park

Bentley WA 6102

Nor th Sydney NSW 2059

1 Clunies Ross Cour t

Telephone:

(08) 9355 15 44

Telephone:

(02) 9931 6666 (0

(of f Miles Platting Road)

Mobile:

0423 614 860

Facsimile:

(02) 9931 6633

Eight Miles Plains QLD 4113

Facsimile:

(08) 9355 1250

Email:

[email protected]

Telephone:

(07) 3853 5320

Email:

[email protected]

Website:

ht tp://steel.org.au http://steel.org.au

Mobile:

0418 788 870

Facsimile:

(07) 3219 9653

Victoria & Tasmania

Email:

[email protected] [email protected] rg.au

Michael Simmons – State Manager

New Sout Sout h Wales & ACT

Phil Casey – State Manager

Redmon on York

Level 13, 99 Mount Street

South Australia

68−72 York Street

Nor orth th Sydn dne ey NS NSW W 20 2060 60

Sam Co Con nto tour uris is – Sta tatte Ma Mana nage gerr,

Sou So uth Me Mellbo bou urn rne e VI VIC C 32 3205 05

Telephone:

(02) 9931 6605

Mobile:

0 425 121 670

Telephone:

(03) 9 694 4499

Mobile:

0 424 225 701

Email:

[email protected]

Mobile:

0412 743 616

Facs acsim imil ile: e:

(02 (0 2) 993 9931 1 663 6633 3

Facsi Fa csimi mile le::

(03) (0 3) 969 9694 4 449 4498 8

Ema mail il::

phil ph ilc@ c@st stee eell.or org g.a .au u

Emai aill:

mic ich hae aels ls@ @st stee eell.or org. g.a au

STEEL CONSTRUCTION—EDITORIAL

. k r o w t e n r u o y m o r f d e t e l e d e . b d t e s t i u b i m h n o r o i p t a e c r i l a b n u o p t i s u i b h i t t r , s I i S d A d e n h t a e m g o a r r f o n t s g , i s e e r s u y k n r a o p w t m o e n c ; r y u p o o y c r d l e u p o a h p S . e d n o e t t i s u l m r p e y p l s n i o r k r e t o u w t p e m n o r c u r o y u o n y o o t n o g i n t i u v b a i r s t s s i d w r o l o l a e e g c a r n o e t c s i l , r e e s s u u : l I S a A n o e s r h t e f p o r u s r o e y : b I m S e A m e e h t t f a r o o s p r r o e c b l m a e i c m n l a a n u i F d . i v t i h d g i n i r y l a p i o c c n I a n S i A F

The Tubular Connection Series is a specialist series devoted to the design of connections for structural steel tubular members, in accordance with the current Australian Standard AS 4100 (Ref. 1). It reflects a wealth of international best practice and the current state of knowledge of tubular connection behaviour from test results. The Tubular Connection Series is structured as a logical companion and in the same format as the existing Structural Steel Connection (for predominantly open section connections), comprising two parts. Part 1, published in 2007, covers simple connections for open sections, including connection theory, bolting and welding related to connections. Part 2, published in 2009, covers rigid connections for open sections and includes recommended design models for a range of rigid connections. The Tubular Connection Series is logically grouped into a number of related connection types and, for each connection type, provides background theory, design models, examples and Design Capacity Tables, all heavily referenced to AS 4100 where appropriate and international best practice where necessary. As such, the Tubular Connection Series provides a very comprehensive compendium of current cutting edge design practice specifically related to an Australian context. Dr Peter Key National Technical Development Manager Aus tra lian lia n Stee S tee l Inst I nst itu te 3D INTERACTIVE CONTENT

ASI is excite exc ite d to presen pre sen t this thi s lat est edi tion tio n of Steel Ste el Constr Con str uct ion Jou rnal rna l ena ble d with wit h 3D intera int eracti cti ve content. We believe the use of 3D has significant benefits in linking educational content to real world application and look forward to the opportunity of exploring this medium further in future technical offerings to industry. Please feel free to provide us feedback on this initiative and we would certainly welcome any 3D content you might be able to provide us for the benefit of the industry. Instructions for interacting with the 3D content in this publication are contained on the inside back cover of this publication. AUSTRALIAN STEEL STEEL INSTITUTE The Australian Steel Institute (ASI) seeks to achieve industry and professional development through regular technical seminars, publishing technical materials and making these available through its bookshop and online, and providing information through its web site www.steel.org.au. site www.steel.org.au. It operates for its members the largest steel technical library in the Southern Hemisphere and provides lectures at colleges and universities as well as hosting a range of committees providing direction and assistance to ASI outputs. Steel Steel Construction Construction is published by the ASI, Australia’s premier technical marketing organisation representing companies and individuals involved in steel manufacture, distribution, fabrication, design, detailing and construction. Its mission is to promote the efficient and economical use of steel. Part of this work is to conduct technical seminars, educational lectures and publish and market technical design aids. Its services are available free of charge to financial corporate members. For details regarding ASI services, readers may contact the Institute’s offices or visit the ASI websit e www.steel.org.au . Disclaimer : Every effort has been made and all reasonable care taken to ensure the accuracy of the material contained in this publication. However, to the extent permitted by law, the Authors,

Editors and Publishers of this publication: (a) will not be held liable or responsible in any way; and (b) expressly disclaim any liability or responsibility for any loss or damage, costs or expenses incurred in connection with this Publication by any person, whether that person is the purchaser of this Publication or not. Without limitation, this includes loss, damage, costs and expenses incurred if any person wholly or partially relies on any part of this Publication, and loss, damage, costs and expenses incurred as a result of the negligence of the Authors, Editors or Publishers. Warning: Warning : This Publication should not be used without the services of a competent professional person with expert knowledge in the relevant field, and under no circumstances should this Publication be relied upon to replace any or all of the knowledge and expertise of such a person. Contributions of original papers or reports on steel design, research and allied technical matters are invited from readers for possible publication. The views expressed in these papers are those of the authors and do not necessarily reflect the views of the ASI. Submissions should be in Microsoft Word including all diagrams and equations in full page format, using Arial font (size 10 point). A clean printout should also be forwarded.

Electronic copies of Steel Construction Construction are available from the members’ section of the ASI website. These PDFs may be freely downloaded by members for their personal use. Financial corporate members of the ASI may add these PDFs to their company intranets but in the event of resignation from the ASI, the PDFs must be deleted. The ASI permits members to quote excerpts from Steel Construction in Construction in their technical reports provided the journal is referenced as the source.

STEEL CONSTRUCTION VOLUME 46 NUMBER 2 – MARCH 2014

1

ASI AS I L IMIT IMI T STA S TATE TE STRUCT STR UCTURA URA L STEEL STEE L TUB UL AR CONNECT CON NECTION ION SERIES SER IES—201 —2014 4 BACKGROUND AND SUMMARY . k r o w t e n r u o y m o r f d e t e l e d e . b d t e s t i u b i m h n o r o i p t a e c r i l a b n u o p t i s u i b h i t t r , s I i S d A d e n h t a e m g o a r r f o n t s g , i s e e r s u y k n r a o p w t m o e n c ; r y u p o o y c r d l e u p o a h p S . e d n o e t t i s u l m r p e y p l s n i o r k r e t o u w t p e m n o r c u r o y u o n y o o t n o g i n t i u v b a i r s t s s i d w r o l o l a e e g c a r n o e t c s i l , r e e s s u u : l I S a A n o e s r h t e f p o r u s r o e y : b I m S e A m e e h t t f a r o o s p r r o e c b l m a e i c m n l a a n u i F d . i v t i h d g i n i r y l a p i o c c n I a n S i A F

by Peter Peter K ey Peter Key is National Technical Development Manager for Australian Steel Institute (ASI). His academic achievements include a Bachelor of Engineering from The University of Sydney with 1st Class Honours and University Medal (prox acc). Postgraduate qualifications include a Doctor of Philosophy from The University of Sydney. Peter is a Member of the Institution of Engineers Australia and he has worked for more than 20 years in the design and construct arena, specialising in large span steel structures.

1

INTRODUCTION

This new series of connection publications by the Australian Steel Institute (ASI) covering design capacity tables, theory and design of individual structural steel hollow section (‘tubular’) member connections will be known as the Structural Steel Tubular Connection Series, 1st edition, 2014 (‘Tubular Connection Series’). The Tubular Connection Series details the method of design and provides design capacity tables and detailing parameters for a range of tubular connections commonly used in Australia. Connections have a major engineering and economic importance in steel structures influencing design, detailing, fabrication and erection costs. Standardisation of design approach integrated with industry detailing is the key to minimum costs at each stage. The Tubular Connection Series is written in the same format as and extends the range of the existing ‘Structural Steel Connection Series’ Parts 1 and 2 for open sections (Refs. 1, 2) published by ASI commenc com menc ing 200 7. Eac h book in the new Tub ula r Con nectio nec tio n Series Ser ies is number num ber ed as a con tinuat tin uat ion from the existing series, commencing with ‘Tubular Design Guide 20’ (TDG 20).

2

BACKGROUND

The ASI was formed in 2002 through the merger of the Australian Institute of Steel Construction (AISC) and the Steel Institute of Australia (SIA). The former AISC published a series of design manuals giving guidance on the design of structural connections in steelwork over the last 30 years. Prior to consideration of tubular section connection design, the AISC published the first Steel Connection Series in 1978 in permissible stress format, at which time connection design theories were developed for the purpose of generating and publishing connection capacity tables for open sections. A series of editions were published, culminating in the fourth edition Design of Structural Connections (Ref. 3) (often referred to as the ‘Green Book’) in 1994 in limit state format. A new Connection Series in limit state format was published in two parts, commencing 2007. Part 1 (Ref. 1), published in 2007, covers simple connections for open sections, including connection theory, bolting and welding related to connections. Part 2 (Ref. 2), published in 2009, covers rigid connections for open sections and includes recommended design models for a range of rigid connections. The former AISC published ‘Design of structural steel hollow section connections – Volume 1: Design models’ (Ref. 4) (often referred to as the ‘Blue Book’) in 1996, covering design models and examples for a range of practical connections for structural steel hollow sections (SSHS). At the time, a companion Volume 2 ‘Standardized Structural Connections’ was planned to update ‘Standardized Structural Connections’, third edition 1985, but this was never released. The current Tubular Design Guide (TDG) series updates and significantly expands the range and depth of models covered in the previous Blue Book and includes in addition design capacity tables (DCT) for most common connection types. The format and structure of the TDG series follows that of the current open section connection series, providing industry with a consistent view of both open and tubular section connection design. The series is designed to be extended with new and updated material as required in the future. Each individual connection type in the tubular connection series contains in a single DESIGN GUIDE standardised detailing and design capacity tables for the connection types covered by that publication, derived using the recommended design models in that publication. Where different connection types are similar in form and function, they are included as separate models within the same design guide publication.

2


3

. k r o w t e n r u o y m o r f d e t e l e d e . b d t e s t i u b i m h n o r o i p t a e c r i l a b n u o p t i s u i b h i t t r , s I i S d A d e n h t a e m g o a r r f o n t s g , i s e e r s u y k n r a o p w t m o e n c ; r y u p o o y c r d l e u p o a h p S . e d n o e t t i s u l m r p e y p l s n i o r k r e t o u w t p e m n o r c u r o y u o n y o o t n o g i n t i u v b a i r s t s s i d w r o l o l a e e g c a r n o e t c s i l , r e e s s u u : l I S a A n o e s r h t e f p o r u s r o e y : b I m S e A m e e h t t f a r o o s p r r o e c b l m a e i c m n l a a n u i F d . i v t i h d g i n i r y l a p i o c c n I a n S i A F

PUBLICATIONS

The Tubular Connection Series has been published as a series of individual closely related publications (booklets). Each covers a particular type or family of connection types. The currently available publications are: Tubular Design Guid e 20 20 – Background Background and design basis Tubular Design Guide 21 – Bolted bracing connections : covering design models for slotted SSHS end connection, welded tee SSHS end connection and flattened end CHS connection Tubular Design Guide 22 – Bolted bracing cleats cleats : covering design models for the bracing cleat, gusset plate and cleat plate assembly Tubular Design Guid e 23 23 – Plate fitments : covering design models for web side plate, moment side plate and transverse plate Tubular Design Guide 24 – Bolted planar connections : covering design models for bolted end plate splice and bolted moment end plate Tubular Design Guide 25 – Fully welded simple planar connections : covering design models for mitred knee and T, Y and X connections Tubular Design Guide 26 – Fully welded gap planar connections : covering design model for K and N gap connections and KT gap connections Tubular Design Guid e 27 – Fully welded overlap planar connections : covering design models for K and N overlap connections and KT overlap connections

4

SCOPE AND B ASIS

The Tubular Connection Series is a specialist series devoted to the design of connections using SSHS in accordance with the current Australian Standard AS 4100 (Ref 5.) where possible, reflecting the current state of knowledge of connection behaviour based on test results, finite element analysis and related international research. There is a large body of international research that has been and continues to be undertaken. This research, and the international specifications and design models resulting from it, has been selectively adopted as the basis for the aspects of the design models presented in this publication, specifically where the behaviour is not directly addressed by AS 4100. Though substantial in various parts, in some instances, the test evidence is sparse and in other instances the evidence is contradictory or clouded. Each design guide in the Tubular Connection Series has been written by weighing the available evidence to provide recommended design procedures based in part on the design procedures used in equivalent manuals and/or published papers. Each design guide is intended to provide a design model which gives a reasonable estimate of connection design capacity and effort has been expended in researching and developing design models which can be jus tified tif ied on the bas is of the ava ila ble res earch ear ch and curre cur rent nt des ign practi pra cti ce. It is to be emph asis ed tha t for the connection models presented, the design model is not necessarily the only possible model and attention is drawn to the disclaimer at the beginning of each publication as to its applicability and use. The connections dealt with are those generally in common use in Australia. Where relevant, the connection elements have been standardised consistent with the earlier AISC ‘Standardized Structural Connections’ publication (Ref. 6) (now out of print) and the embodiment of this in the later ASI publications ‘Design Capacity Tables for Structural Steel’ Volumes 3 and 4 (Refs. 7, 8). An explanation of the standardisation relevant to each connection type is included in the relevant design guide. Tubular Design Guide 20 (TDG 20) provides the background, design basis and principles common to all the connection types. There is an extensive range of information which forms the foundation for the design models, together with product specific data applicable to the range of sections available from the local manufacturers. Major sections are presented on the basis for design to AS 4100, background to SSHS implementation, material and section properties (including international material sourcing), design capacities for bolts, welds and components, detailing and standardisation and truss design considerations. As a han dy refer re fer enc e to all thi ngs SSHS SSH S for the Austra Aus tralia lia n market mar ket , TDG 20 its elf is a mustmus t- have hav e refere ref erence nce for the engineer. Each of Tubular Design Guides 21 to 28 presents standardised detailing parameters, the design model historical and theoretical basis, a series of the relevant design checks, one or more design examples and, STEEL CONSTRUCTION VOLUME 46 NUMBER 2 – MARCH 2014

3

where possible, design capacity tables for the connection types covered by that design guide, derived using the design models in that design guide. Each design guide contains a collection of similar connection types, related by either configuration of the connection or the type of structural assembly in which it is used. . k r o w t e n r u o y m o r f d e t e l e d e . b d t e s t u i b i m h n o r o i p t a e c r i l a b n u o p i t s u i h b i t r , t I s i S d A d e n h t a e m g o r a r f o n t g s i , s e e r s u y k n r a o p w t m o e c n r ; y u p o o y c d r l u e o p h a p S . e d n e o t t i s u l m r p e y p l s n i o r k r e t o u w t p e m n o r c u r o u y o n y o o t n o g i n t i u v b a i r s t s s i d w o r l o l a e e g c a r n o e t c s i l , e r s e u s u : l I S a A n o e s h r e t f p o r s u r o e y : b I m S e A m e e h t t f a r o o s p r r e o b c l m a e i c m n l a a n u i d F i . i v t h d g i n i r l y a p i o c c n I a n S i A F

Each Tubular Design Guide is configured to be self-standing and able to be used independently of any other. Each Tubular Design Guide therefore contains core data related to the material properties and component strengths. However, where greater in-depth reference is required to the basis for the design models or property or section information, the reader should refer to TDG 20.

5

BASIS OF SSHS CONNECTION DESIGN TO AS 4100

5.1 General con sid eration s The Australian Steel Structures Standard AS 4100 (Ref. 5) contains the requirements applicable to the design of steel structures, including connections. A companion document, AS 4100 Supplement 1 (Ref. 9), provides a commentary to th e code provisions. Section 9 of AS 4100, titled ‘Connect ions’, defines the design requirements specific to connection components and the connection as a whole.

In structural steel connections, there are three fundamental considerations: (a)

the connection designer requires a realistic estimate of connection strength in order that a connection will be safe (design capacity exceeds design actions) and economical (not over-designed);

(b)

the connection designer requires a realistic understanding of the serviceability and ductility requirements of the connection, including connection stiffness, in order that the design assumptions inherent in the analysis of the overall structure (of which the connections are a part) are consistent with the expected behaviour of the connection; and

(c)

the connection must be detailed in such a way that it is economical to fabricate and erect, while recognising that the connection detailing may have an important impact on the strength, stiffness and ductility of the connection and, indeed, of the overall structure.

Any des ign model for assessing the str ength of a con nection must take account of the following four elements: (i)

the strength of the fasteners (bolts and welds);

(ii)

the strength of the connection components (plates, flat bars, angles, gusset plates);

(iii)

the strength of the connected (or supported) member in the vicinity of the connection (local effects);

(iv)

the strength of the supporting member in the vicinity of the connection (local effects).

Connection stiffness and serviceability are particularly relevant to hollow section connections where, unlike open section connections which generally contain secondary cleats, stiffeners and other bolted or welded components that may be configured to condition the behaviour of the connection (pinned versus moment behaviour for example), hollow sections are often profile cut and fully welded together to produce a connection that contains no secondary components. The stiffness of these connections is predominantly a function of the connection geometry and wall slenderness of the connected faces of the individual members, with little opportunity to create the idealized pin or moment connection that is afforded by sympathetic configuration of secondary connection components. Standards and codes for the design of steel structures primarily deal with member design as a whole, rather than specifically allowing for local effects, and provide only the basic information on elemental (e.g. fastener, weld, plate) connection design. These documents typically do not specify a detailed design procedure for any type of multi-element connection, leaving the assessment of how a connection behaves and how its behaviour should be allowed for in design to the individual designer. AS 4100 further states that “Design shall be on the basis of a recognised method supported by experimental evidence”. The variation in behaviour between different connection types, and the need for design to be based on experimentally substantiated methods, presents the designer with a substantial task considering the large number of different connection types that may be encountered, each requiring individual research and assessment. The Tubular Connection Series seeks to assist the designer by providing guidance in order to reduce the task considerably.

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5.2

Connection design models

The basic requirements that any connection design model must conform to if the design model is to be acceptable are laid out in Clause 9.1.3 of AS 4100 (Ref. 5). These requirements are as follows: . k r o w t e n r u o y m o r f d e t e l e d e . b d t e s t u i b i m h n o r o i p t a e c r i l a b n u o p i t s u i h b i t r , t I s i S d A d e n h t a e m g o r a r f o n t g s i , s e e r s u y k n r a o p w t m o e c n r ; y u p o o y c d r l u e o p h a p S . e d n e o t t i s u l m r p e y p l s n i o r k r e t o u w t p e m n o r c u r o u y o n y o o t n o g i n t i u v b a i r s t s s i d w o r l o l a e e g c a r n o e t c s i l , e r s e u s u : l I S a A n o e s h r e t f p o r s u r o e y : b I m S e A m e e h t t f a r o o s p r r e o b c l m a e i c m n l a a n u i d F i . i v t h d g i n i r l y a p i o c c n I a n S i A F

“Each element in a connection shall be designed so that the structure is capable of resisting all design actions. The design capacities of each element shall be not less than the calculated design action effects. Connections and the adjacent areas of members shall be designed by distributing the design action effects so that they comply with the following requirements: (a)

The distributed design action effects are in equilibrium with the design action effects acting on the connection.

(b)

The deformations in the connection are within the deformation capacities of the connection elements.

(c)

All of the connection elements and the adjacent areas of members are capable of resisting the design action effects acting on them.

(d)

The connection elements shall remain stable under the design action effects and deformations.

Design shall be on the basis of a recognised method supported by experimental evidence. Residual actions due to the installation of bolts need not be considered.” The onus is placed on the structural steel designer to ensure that the actual behaviour of a connection does not have a deleterious effect on the members of the steel frame and that the connection conforms to the requirements specified in AS 4100. 5.3

Connection terminolo gy

Connections are considered in the Tubular Connection Series and in AS 4100 to consist of the following connection elements: (A)

fasteners (bolts or welds) (‘connectors’ in AS 4100 terminology);

(B)

components (plates, gussets, cleats);

(C)

supported members;

(D)

supporting members.

These elements are defined in relation to a typical hollow section connection in Figure 1.

FIGURE 1

DEFINITION OF CONNECTION ELEMENTS


5

. k r o w t e n r u o y m o r f d e t e l e d e . b d t e s t u i b i m h n o r o i p t a e c r i l a b n u o p i t s u i h b i t r , t I s i S d A d e n h t a e m g o r a r f o n t g s i , s e e r s u y k n r a o p w t m o e c n r ; y u p o o y c d r l u e o p h a p S . e d n e o t t i s u l m r p e y p l s n i o r k r e t o u w t p e m n o r c u r o u y o n y o o t n o g i n t i u v b a i r s t s s i d w o r l o l a e e g c a r n o e t c s i l , e r s e u s u : l I S a A n o e s h r e t f p o r s u r o e y : b I m S e A m e e h t t f a r o o s p r r e o b c l m a e i c m n l a a n u i d F i . i v t h d g i n i r l y a p i o c c n I a n S i A F

The design capacities of all of these elements must be evaluated in order to evaluate the design capacity of the connection. TDG 20 deals with the theoretical background and design basis of these elements as isolated elements so that the formulae derived can be used in later guides concerned with individual connections. Design data is only repeated to a limited extent in Tubular Design Guides 21 to 27, sufficient to establish and document element capacities for use in the design models. The design models contained within the Tubular Connection Series are considered to be applicable only to connections which are essentially statically loaded. Connections subject to dynamic loads, earthquake loads or fatigue applications may require additional considerations. Fatigue loading and earthquake loading may be the subject of later design guides.

6.0

ADVANTAGES OF SSHS FOR CONSTRUCTION

Structural steel hollow sections (SSHS) have a long history of project implementation and an equally long history of development as a high performance building product. This pedigree is reflected in the fact that compared to other steel products, the worldwide consumption of welded steel tubular products is increasing in a market share sense if not an overall sense.

FIGURE 2

METRICON STADIUM ROOF – ILLUSTRATING THE AESTHETIC OF EXPOSED SSHS

There are numerous reasons for the increased focus on and use of SSHS, and many speak towards the advantages of SSHS for production, supply and building and infrastructure construction. These include: 1.

A world steel industry moving from the traditional production of hot-rolled sections and plate towards coil and strip production with attendant advantages of easier delivery from steel mill to manufacturing plant and the capacity to supply pre-coated (galvanized or primer-painted) product in some cases.

2.

Improved manufacturing technology which facilitates enhancement of the overall performance of the product.

3.

Structural steel design Standards which permit design of cold-formed SSHS sections along with hotrolled sections are now available in most countries around the world. These Standards have been continually improved, enabling the design of cold-formed SSHS members and connections to take advantage of the increased performance produced by the manufacturing process and inherent in the products.

4.

The inherent structural efficiency of the hollow section shape, which places material at the maximum distance from the centroid of the section. Increased compression load capacity, torsional strength and stiffness and lateral stability per unit weight are direct advantages of the hollow section shape and lead to structures that, on a per unit area basis, are amongst the lightest that can be designed.

6



5.

A per unit mass cost which, whilst usually higher than for hot-rolled open sections, has reduced relative to hot-rolled sections.

6.

SSHS combines resistance to wind, water or wave loading with an architecturally stimulating and aesthetic shape, characteristics which combine to naturally lend themselves to exposure in landmark structures with open light designs. The smaller surface area than comparable structures with open sections and the absence of sharp corners and reduced ledges result in better corrosion protection in these applications.

Critical to the design of structures comprising SSHS framing is the efficient and sympathetic design and detailing of connections, often with no or minimal cleats or stiffening plates. Since the connection strength is influenced by the geometric properties of the members, the designer must understand the nuances of hollow section connection design and the consequent ever present conflict between member size and shape and the desirable elimination of ancillary stiffening/strengthening plates and the like. A strong appreciation of these issues is needed at conceptual design stage in order to ensure optimal design. The Tubular Connection series is intended to provide the designer with the tools necessary to identify the most cost effective and sympathetic design and detailing balance.

7

AUSTRALIAN CONTEXT

7.1

Australian produ ction

Structural steel hollow section (SSHS) produced in Australia, comprising circular hollow sections (CHS), square hollow sections (SHS) and rectangular hollow sections (RHS), are supplied by a number of Austra lian manufacturers to the joint Australian-New Zealand Stan dard AS/NZS 1163 Cold-f ormed str uctural steel hollow sections (Ref. 10). Australian produced SSHS are exclusively manufactured by a cold-forming process with no significant pre-, intermediate or post-heat treatment, resulting in a product with enhanced strength properties compared to the base material. Alternative manufacturing processes used in other international markets, such as hot forming, may result in a different set of material properties and hence section behaviour. It is therefore important to confirm the product type and reference Standard as part of the design process. In Australia, approximately 40% of the structural steel used each year comprises SSHS, making SSHS a substantial component of the total market consumption. SSHS product is used as structural members in steel construction, roadside hardware (signage gantries, guard and hand rails, pedestrian bridges), framing components in vehicles and equipment and for recreational equipment, to name a few. Manufacturers in Australia supply SSHS to a range of section sizes broadly corresponding to that indicated in Table 1. TABLE

1

RANGE OF SECTION SIZES AVAILABLE FROM AUSTRALIAN MANUFACTURERS

Section

Minimum si ze (overall di mensions x wall t hickness) (mm)

Maximum size (overall di mensions x wall t hickness) (mm)

CHS

26.9 x 2.0

508.0 x 12.7

SHS

20 x 20 x 1.6

400 x 400 x 16

RHS

50 x 20 x 1.6

400 x 300 x16

The range of standard section sizes and grades usually available in Australia is tabulated in detail in Append ix A of TDG 20. This sectio n size range and grades is used as the basis for input into the des ign capacity tables included with each design model developed in the connection series. It is relevant to note that Australian manufacturers also variously import some section sizes that are manufactured overseas to Austra lian Standards in compliance with the particular qua lity and fac tory production control regimes of the Austra lian man ufacturer . These sec tions may be considered equal to the Austra lian man ufactured sec tions and designed utilising the section properties and design capacity tables provided by the particular Austra lian manufacturer.


7

Avai lab il ity of spec ific sec tion sizes sh ould al w ay s be chec ked with th e man ufac turer s an d/o r stockists/distributors, as not all section sizes are produced in all grades. In particular, individual manufacturers may focus on production of a particular shape in one grade only. C450 material may be available as ‘dual graded’ to C350 requirements also. Check the appropriate technical literature. . k r o w t e n r u o y m o r f d e t e l e d e . b d t e s t u i b i m h n o r o i p t a e c r i l a b n u o p i t s u i h b i t r , t I s i S d A d e n h t a e m g o r a r f o n t g s i , s e e r s u y k n r a o p w t m o e c n r ; y u p o o y c d r l u e o p h a p S . e d n e o t t i s u l m r p e y p l s n i o r k r e t o u w t p e m n o r c u r o u y o n y o o t n o g i n t i u v b a i r s t s s i d w o r l o l a e e g c a r n o e t c s i l , e r s e u s u : l I S a A n o e s h r e t f p o r s u r o e y : b I m S e A m e e h t t f a r o o s p r r e o b c l m a e i c m n l a a n u i d F i . i v t h d g i n i r l y a p i o c c n I a n S i A F

The stress grades of SSHS commonly produced in Australia are 250 MPa (called C250), 350 MPa (called C350) and 450 MPa (called C450), the ‘C’ referring to cold-formed and the numeral referring to the minimum yield stress of the product material. The C350 material has the strength enhanced from the approximate 300 MPa feed material through cold work in the manufacturing process. The C450 grade is achieved through use of additional alloying elements in the steel feed together with cold work from the manufacturing process. The material properties specified in AS/NZS 1163 are given in Table 2 for minimum values of yield stress, tensile strength and elongation to which SSHS produced to the Standard must conform. TABLE

2

MINIMUM SSHS MATERIAL PROPERTIES TO A S/NZS 1163 Minimum elongation as a proportion of th e gauge length

Grade

Minimum yield strength

 (

7.2

Minimum tensile strength

)

 (

% Circular hollow sections

 ⁄

)

Rectangular hollow sections

 ⁄  ⁄  ,

MPa

MPa

≤ 15

>15 ≤ 30

> 30

≤ 15

>15 ≤ 30

> 30

C250, C250L0

250

320

18

20

22

14

16

18

C350, C350L0

350

430

16

18

20

12

14

16

C450, C450L0

450

500

12

14

16

10

12

14

Australian design context

The applicable Standard for SSHS design in Australia is AS 4100 Steel structures (Ref. 5). AS 4100 was first published in limit states format in 1990. Whilst the development of AS 4100 was based largely on hotrolled open section members, it did permit the use of cold-formed hollow section members to AS/NZS 1163 Cold-formed structura l steel hollow sections (Ref. 10 ). The previous permissible str ess based AS 1250 (Ref. 11) had also allowed cold-formed SSHS members since an amendment in 1982. AS 410 0 specif ically includ es cold-f ormed SSHS to AS/NZS 1163 as within the sco pe of the Standard in Clause 1.1.1, including members with wall thicknesses less than 3 mm, which would otherwise be excluded according to Clause 1.1.1(a). Section 4.5.2 of AS 4100 provides limitations for plastic analysis including, amongst other limitations, that plastic analysis is limited to hot-formed members that are doubly symmetric I-sections. Therefore, coldformed SSHS sections cannot be used for plastic design to AS 4100. However, separate work undertaken by industry has shown that, in some instances, the plastic analysis and design of cold-formed SSHS can be undertaken. A sig nificant research effort on cold-f ormed hollow section member and connection beh aviour has bee n undertaken both in Australia and internationally in the last 30 years, as outlined in TDG 20. The outcomes of these research programs have now largely been incorporated into the latest Australian Standard AS 4100 (Ref. 5) and the New Zealand Standard NZS 3404 (Ref. 12), as well as the other international standards and specifications discussed in TDG 20. 7.3

International design context

SSHS member and connection design is firmly established internationally and draws on a pool of international research for continuing evolution and refinement, driven by both increased understanding of member and connection behaviour and improved manufacturing processes resulting in higher performance sections.

8



In the USA, SSHS can be designed to the American Institute of Steel Construction (AISC) Specification (Ref. 13). The current AISC Specification has merged permissible stress and limit state versions which previously had allowed SSHS design since their 1969 and 1986 editions respectively. Ref. 14 recently included hollow section connection design guidance in Appendix K. The AISC had also produced a specific manual on the design of hollow structural section connections (Ref. 15). In Canada, cold-formed SSHS is designed to the CSA-S16-01 (Ref. 16) steel structures Standard. The British Standard BS 5950 Part 1 (Ref. 17) included design of cold-formed tubular members in the 2000 update, at which time the design of cold-formed structural hollow sections was transferred across from BS 5950 Part 5 Code of Practice for design of cold-formed thin gauge sections (Ref. 18). New Zealand Standard NZS 3404.1 (Ref. 12) allows design of materials to AS/NZS 1163, hence coldformed tubular members. Table 3 of NZS 3404.1 excludes the use of materials with a yield stress greater than 360 MPa for category 1 and 2 seismic members, unless testing shows the specific member and connection behaviour to be compliant with the Standard’s requirements. Eurocode 3 (Ref. 19) includes design of structural hollow sections through Table 3.1 and the specification of allowable standards and steel grades for structural hollow sections, both hot-finished and cold-formed, up to 460 MPa nominal yield stress. 7.4

Design aspects related to Aust ralian SSHS

7.4.1

Influence of higher strength steel on SSHS connection design

The various connection design models elaborated in the Tubular Connection Series each comprise a range of checks of different aspects of connection component behaviour. Where relevant design checks are available in AS 4100 (Ref. 5), these are used in the design models. However, for a range of design checks, typically those associated with the behaviour of the actual SSHS sections (as distinct from any connection components) no corresponding design checks are available in AS 4100. In these cases, rules from international codes and specifications, in particular the CIDECT Design Guide Series 1 and 3 (Refs. 20, 21) have been adopted. The CIDECT Design Guides f or CHS (Ref. 20) and for SHS/RHS (Ref. 21) in Section 1.2.1 discuss limitations on materials in respect of the range of applicability of the design models presented. The connection resistances given in Refs. 20 and 21 are based on SSHS with a nominal yield strength up to 355 MPa. For nominal yield strength greater than 355 MPa and up to 460 MPa, the connection resistances given in the CIDECT guides should be multiplied by 0.9. As noted in the CIDECT guides, “this provision considers the relatively large deformations that take place in joints with nominal yield strengths of approximately 450 to 460 MPa when plastification of the connecting RHS face occurs” and notes its application to other failure modes may be conservative. The ultimate limit state load is assessed in the CIDECT models with a deformation limit imposed corresponding to 3% of d 0 or 3% of b 0 , which is sometimes reached with higher strength SSHS under chord face plastification failure modes. 7.4.2

Influence of yield to ultimate tensile strength ratio on SSHS connection design

The various international codes and specifications have generally adopted an allowable maximum ratio of yield stress to ultimate tensile strength of f y/ f u = 0.8. The CIDECT Design Guides 1 and 3 (Refs. 20, 21) recommend that the allowable ‘design yield stress’ used for computations should not be taken as greater than 0.8 of the nominal ultimate tensile strength. This yield-to-ultimate limitation recognises the need for ample material ductility for cases where less ductile modes of failure, such as punching shear failure or ‘local yielding of brace or plate’ failure, govern. It is instructive to examine how the yield-to-ultimate tensile strength limitation is interpreted in the various international codes and specifications. In Canada, CSA G40.20/G40.21 Grade 350W material has a nominal yield-to-ultimate stress ratio of 350 MPa / 450 MPa = 0.78, meaning the reduction factor is not required. This material represents less than 50% of the SSHS material produced in Canada, with the remainder to ASTM A500 (Ref. 22) . In the United Stat es, all SSHS material is produced to ASTM A500, where the Gra de C material (nominal yield stress of 345 MPa) has a yield-to-ultimate tensile strength ratio of 50 ksi/62 ksi = 0.806, putting it marginally above the 0.8 limit. However, the AISC 360-10 Specification 2010 Edition (Ref. 14) in Tables K1.2A, K2.1A, K2.2A, K3.1A and K3.2A notes that ASTM A500 Grade C is acceptable without further design capacity reduction.


9

Cold-formed tubular material to Eurocode 3 (Ref. 19) should meet the requirements for yield strength and ultimate tensile strength given in Table 3.1 of Eurocode 3 and reproduced in Table 3 following, together with the yield-to-tensile strength ratio. These material properties are based on EN 10219-1 (Ref. 23). A number of product grades are above the 0.8 limit and require the reduction factor to be applied. . k r o w t e n r u o y m o r f d e t e l e d e . b d t e s t u i b i m h n o r o i p t a e c r i l a b n u o p i t s u i h b i t r , t I s i S d A d e n h t a e m g o r a r f o n t g s i , s e e r s u y k n r a o p w t m o e c n r ; y u p o o y c d r l u e o p h a p S . e d n e o t t i s u l m r p e y p l s n i o r k r e t o u w t p e m n o r c u r o u y o n y o o t n o g i n t i u v b a i r s t s s i d w o r l o l a e e g c a r n o e t c s i l , e r s e u s u : l I S a A n o e s h r e t f p o r s u r o e y : b I m S e A m e e h t t f a r o o s p r r e o b c l m a e i c m n l a a n u i d F i . i v t h d g i n i r l y a p i o c c n I a n S i A F

TABLE

3

COLD-FORMED SSHS MATERIAL PROPERTIES TO EN 10219-1 Minimum yield strength


( f y )

( f u )

MPa

MPa

S 235 H

235

360

0.65

S 275 H

275

430

0.64

S 355 H

355

510

0.70

S 275 NH/NLH

275

370

0.74

S 355 NH/NLH

355

470

0.76

S460 NH/NLH

460

550

0.84

S 275 MH/MLH

275

360

0.76

S 355 MH/MLH

355

470

0.76

S 420 MH/MLH

420

500

0.84

S 460 MH/MLH

460

530

0.87

Grade

7.4.3

Yield-to-ultimate tensile strength f y / f u

Design yield stress for Australian produced SSHS

Austra lian SSHS produced to AS/NZS 116 3 (Ref. 10) has yield-to- ultimate ten sile streng th values give n in Table 4 for the C250, C350 and C450 grades. With a ratio of 0.78, Grade C250 does not require a reduction factor to be applied. With a ratio of 0.81, Grade C350 is marginally above the limit of 0.8 but is deemed acceptable to use without a reduction factor. Grade C450 has a yield-to-ultimate tensile strength of 0.90 and requires a reduction factor to be applied. The ‘design yield stress’ for C450 material used for connection design for less ductile modes of failure like punching shear failure or ‘local yielding of brace or plate’ should therefore be 0.8 x 500 MPa = 400 MPa. TABLE

4

SSHS MATERIAL PROPERTIES TO AS/NZS 1163 Minimum yield strength Grade

 (

)

MPa

10




Yield-to-ultimate

MPa

 ⁄ 

(

)

C250, C250L0

250

320

0.78

C350, C350L0

350

430

0.81

C450, C450L0

450

500

0.90



The reduction factor discussed in Section 7.4.1 of 0.9 for ductile failure modes, which effectively equates to a reduction in design yield stress to 0.9 x 450 = 405 MPa (since the face plastification failure mode is a linear function of yield stress), together with the yield-to-ultimate tensile strength limiting reduction of 0.8 x 500 = 400 MPa discussed in Section 7.4.2 for t he less ductile failure modes, c overs the range of failure modes normally associated with the SSHS members in the connection. Based on this rationalisation, the recommended design yield stress (Φm f y) to be used in design checks for failure modes associated with the SSHS component of the connections in this SSHS connection series is given in Table 5 for the range of SSHS grades produced in Australia to AS/NZS 1163, where Φ m is the ‘material reduction factor’. TABLE

5

DESIGN YIELD STRESS FOR SSHS RELA TED FAILURE MODES FOR SSHS TO AS/NZS 1163 Minimum yield strength


( f y )

( f u )

Design yield stress (Φ m f y )

MPa

MPa

MPa

C250, C250L0

250

320

250

C350, C350L0

350

430

350

C450, C450L0

450

500

400

Grade

7.4.4

Section classification

International codes and specifications classify sections according to the slenderness of the individual plate elements that comprise the section and the consequent propensity for these to locally buckle, either elastically or inelastically, under applied compressive or bending stress. Plate element buckling limits the ability for the sections to carry additional load and, depending on the slenderness of the plate elements, can instigate dramatic load shedding by the section as the plate elements buckle. This classification is therefore a measure of the ductility of the section after first yield is reached.

λ e

Clauses 5.2.3, 5.2.4 and 5.2.5 of AS 4100 (Ref. 5) provide a classification for sections as compact , noncompact or slender (C, N or S respectively), based on the value of plate element slenderness, λ e , for the most slender element of the cross section, compared to two slenderness limits, the yield limit, λ ev , and the plasticity limit, λep . Eurocode 3 (Ref. 19) provides a classification of sections as Class 1 , Class 2 , Class 3 or Class 4 , based on constituent plate slenderness. Table 6, reproduced from Ref. 24, indicates the alignment between section classification terminology in a number of international design standards. The alignment shown between section classifications is broadly consistent, although there are small differences between class limits and also differences in the particular measure of geometry used to define the element slenderness. TABLE

6

CLA SSIFICATION OF SECTIONS IN VARIOUS DESIGN STANDARDS Specification

Section classification

Eurocode 3

Class 1

Class 2

Class 3

Class 4

BS5950

Plastic

Compact

Semi-compact

Slender

AS 4100

Compac t

Non -compact

Slende r

AISC LRFD

Compac t

Non -compact

Slende r


11


AS 410 0 does not pro vide s pecific guidance on sectio n classification in relation to SSHS c onnection design. The section classification in Clauses 5.2.3, 5.2.4 a nd 5.2.5 of AS 4100 relate purely to cr oss sectional strength. However, the design models detailed in CIDECT Design Guides 1 and 3 (Refs. 20, 21) and on which a number of the SSHS related failure modes in the design models described in this connection series are based, have a validity range limited to Class 1 and Class 2 sections as defined in Eurocode 3 (Ref. 19). Therefore, the same section class restrictions are imposed on the design rules specified in the Tubular Connection Series. The flange slenderness definitions and flange and CHS slenderness limits for AS 4100 and Eurocode 3 are given in Table 7. The definition of the face slenderness varies between the two codes, and is based on the measurements indicated in Figure 3(a) for AS 4100 and Figure 3(b) for Eurocode 3. TABLE

7

CLA SSIFICATION OF SECTIONS IN VARIOUS DESIGN STANDARDS Element

Specificatio n

AS 410 0

Slenderness definition

 −   y  − o o y o 2

Slenderness limi ts Class 1, or compact

Class 2

Class 3, or non-compact

30

–

40

250

Flange Eurocode 3

AS 4100 CHS Eurocode 3

2

250

33



′

50

50

38



′

–

2 ′

70

42



′

120

2 ′

90

2 ′

NOTES: 1. 2.

3.

 � ⁄y ′

=

235

for use in Eurocode 3 (Ref. 19).

The AS 4100 slenderness limits are based on Table 5.2 of AS 4100 for cold-formed (CF) material for plate elements with both sides supported.

o

is the external radius of the corners of the SHS/RHS, as defined in AS/NZS 1163 (Ref. 10).

(a) AS 4100

FIGURE 3

12

(b) Eurocode 3

DEFINITION OF ELEMENT WIDTH FOR RHS FLANGES



The Australian section size tables provided in Appendix A to Tubular Design Guide 20 list the class designation according to Eurocode 3 for each section size. Section sizes designated Class 3 or 4 fall outside the limits of applicability of the design checks provided in this connection series. SSHS connection design involving Class 3 or Class 4 sections would therefore require considerable engineering judgement and verification and likely specific attention to stiffening or strengthening for failure modes related to local plate stability or bending.

8 8.1

INTERNATIONAL MATERIAL SOURCING Background

The design engineer may be faced with reviewing and approving SSHS product that has not been sourced from Australian manufacturers and may not be certified to the relevant Australian product or design Standards, or claims to comply but has limited certification documentation. There is a legislative requirement that the majority of projects in Australia are required to conform to the Building Code of Austra lia (Ref. 36), which calls up compliance to AS 4100 and therefor e in tur n the rel evant Australian product Standards for the deemed-to-satisfy route. This section provides design engineers with guidance on the technical aspects that must be addressed in any rational review of imported product. It must be noted that the Austr alian Design Standard AS 4100 (Ref. 5) relies on guar anteed values for chemical composition, mechanical properties, dimensional tolerances, methods of manufacture and quality control provisions for all materials used in a steel structure. These are implicit through reference to product standards such as AS/NZS 1163 (Ref. 10) in the case of SSHS member design. AS 4100, and in particular the capacity factors (Φ), column curves, element slenderness ratios etc, have been calibrated through the use of safety indices against expectations on variation in material strength, material properties, member size and homogeneity, testing results, design model inaccuracy and assumptions, degree of ductility and reliability of the member or connection element under the action effects, all based on Australian product Standards and Australian design, fabrication and construction practice. Ascertaining the veracity of substituted internationally sourced materials or fabricated products is therefore not a trivial task. The issues discussed below draw on a body of work that has been undertaken by ASI over a number of years, which has included significant feedback from industry, technical research and product testing. Whilst the major thrusts of this body of work are technical, invariably regulatory and legislative overlays must be complied with. 8.2

Material persp ectiv es

Applicability of and equ ivalence in material performance is, based on the perfor mance assumptions noted above in relation to AS 4100 code calibration, a primary focus area when considering the appropriateness of imported material. The paper ‘Effect of material properties on hollow section performance’ (Ref. 25) provides a current and exhaustive comparison of the pertinent material properties from a large range of international hollow section product standards, including examination of issues concerning corner cracking, tolerance variations between specifications, suitability for galvanizing and the effect of the material on seismic performance. It leaves little doubt that there are variations between product standards that must be understood and allowed for when addressing sourcing internationally. In addition to the issues noted in Ref. 25, there are a number of material related perspectives that the designer must address in considering the suitability of internationally sourced material: 1.

As discussed in Section 7.4, certain SSHS related failure modes adopted in the Tubular Design Guides are based on the significant research and theoretical models presented in the CIDECT Design Guides 1 and 3 (Refs. 20, 21). For material design yield stress over 355 MPa, CIDECT recommends the use of a reduction factor of 0.9 on the joint resistances calculated for these failure modes. The reduction factor of 0.9 has been adopted for the Tubular Connection Series models also. Imported material with nominal design yield stress greater than 355 MPa should have this factor applied in the relevant design calculations.

2.

As discussed in Section 7.4.2, the relevant design models adopted from CIDECT Design Guides 1 and 3 (Refs. 20, 21) are based on a limiting yield to tensile ratio of 0.8. For imported material which exceeds this ratio, the design yield stress used for the corresponding failure modes should be 0.8. reduced such that

⁄ ≤


13

These material issues are non-trivial and must be addressed to ensure structural safety and reliability is not compromised. 8.3 . k r o w t e n r u o y m o r f d e t e l e d e . b d t e s t u i b i m h n o r o i p t a e c r i l a b n u o p i t s u i h b i t r , t I s i S d A d e n h t a e m g o r a r f o n t g s i , s e e r s u y k n r a o p w t m o e c n r ; y u p o o y c d r l u e o p h a p S . e d n e o t t i s u l m r p e y p l s n i o r k r e t o u w t p e m n o r c u r o u y o n y o o t n o g i n t i u v b a i r s t s s i d w o r l o l a e e g c a r n o e t c s i l , e r s e u s u : l I S a A n o e s h r e t f p o r s u r o e y : b I m S e A m e e h t t f a r o o s p r r e o b c l m a e i c m n l a a n u i d F i . i v t h d g i n i r l y a p i o c c n I a n S i A F

Product perspectives

There are a number of product related issues that need to be considered: 1.

Tolerances on product geometry should be reviewed. Whilst a number of international product specifications have essentially similar tolerances to AS/NZS 1163 (Ref. 10), this is not exclusively the case. For example, Packer et al. (Ref. 25) point out that product produced to ASTM A500 (Ref. 22) is noted for its very liberal geometric production tolerances, with a tolerance of –10% permitted on wall thickness and no tolerance on mass, weight or cross-sectional area, resulting in tubes being produced routinely undersize. Code calibration, such as that undertaken for AS 4100 noted above, is not intended to accommodate liberal and systematic under sizing, the results of which therefore impinge on the assumed safety indices.

2.

Pressure pipe or ‘line pipe’ is often utilised for structural applications. In fact, a proportion of the Australian manufactured pro duct was dual rated to bot h AS/NZS 1163 and also pressure pipe Standards such as API (Ref. 26). When presented with international product that is certified to a pressure pipe Standard but intended for use in a structural application, great care should be taken in assessing the appropriate design yield stress based on mill or test certificates supplied with the product. Pressure pipe is usually tensile tested in the circumferential direction (being the direction of principal stress for pressure applications), which is also the direction of primary cold work and hence yield stress increase resulting from the cold-forming process. Actual yield stress in the longitudinal direction (which is the direction structural tube is tested in and reported on) can be up to approximately 50 MPa less than the yield stress in the circumferential direction. The practical result is that a pressure pipe with a reported yield stress of 250 MPa (in the circumferential direction) may have an actual yield stress as usually reported for structural purposes of only 200 MPa.

3.

The section classification, as discussed in Section 7.4.4, should be checked for applicability against the limits for the connection models in the Tubular Connection Series. These are no different to the considerations for Australian manufactured product but the designer needs to be aware that the sections may not be classified in any property or design capacity tables received with the product and therefore the classification will have to be calculated and checked separately.

The broader issues ass ociated with designing to AS 4100 when imported mate rials are concerned have been documented in two ASI Technical Notes: •

•

8.4

Technical Note TN005 ‘Guidelines for designing to AS 4100 when imported materials are involved’ (Ref. 27) Technical Note TN007 ‘Compliance issues and steel structures’ (Ref. 55) Bolt sourci ng

At the time of writing, the majority o f commerc ial (Property Class 4.6) and high s trength (Pro perty Class 8.8) bolts used in Australia that the structural designer is likely to specify are imported. Only certain high performance and niche market products are still manufactured in Australia. It is also a reality that price pressures, tendering competition and a regulatory regime where normative conformance is not yet widely implemented has resulted in both documented and anecdotal evidence that structural bolts which do not comply with the Australian structur al bolting Standard AS/NZS 1252 (Ref. 29) are regular ly entering the market. Over a number of years ASI has undertaken awareness campaigns, producing a range of technical information directed at the engineering and specifying community. This information has included: •

•

‘Are you getting the bolts you specified? A discussion paper’, Dec., 2005 (Ref. 30) ASI Tech Note #1-06 ‘High strength bolt assemblies. Certification to AS/NZS 1252—1996 … Reject or Accept ?’, Jan., 2007 ( Ref. 31)

•

TN001 ‘High strength structural bolt assemblies to AS/NZS 1252’, 2011 (Ref. 32)

•

Section 9 of Ref. 33 which includes a discussion on certification to AS/NZS 1252

14


Summarising the significant issues: •


•

•

Bolt suppliers (usually importers in the current Australian context) must verify and provide documentary evidence of compliance to the relevant Australian Standards (AS/NZS 1252 – Ref. 29) and the corresponding product standards. Purchasers and certifiers must demand this documentation. In the current market climate, the veracity of a manufacturer’s test certificate cannot be assumed. In addition, a test certificate, or test report on an individual bolt (regardless of whether locally provided by a registered laboratory), only provides a snap shot of the product quality and does not address the necessary in-process controls during manufacture or the statistical basis on which product conformance should be based. Therefore, locally based testing of individual or a small sample of bolts should only be viewed as confirming the veracity of a batch of bolts that already have adequate and proper auditable compliance documentation in place (as supplied by the importer or distributor). The detailed requirements for proper compliance documentation are discussed in the ASI documentation (Refs. 30, 31, 32). The confirmation of this compliance documentation is an important and necessary task that each purchaser must undertake in order to demonstrate an adequate duty of care. Recent Workplace Health and Safety (WH&S) legislation (Ref. 34) is placing greater responsibility on the whole process chain to document and collaborate transparently on safety issues, the safety aspects of non-compliant products being a relevant facet.

Compliance auditing is not a trivial task and in many cases difficult for purchasers to have the necessary depth of understanding or resources to properly undertake. ASI is recommending to the industry that an appropriate solution should include a rigorous third party product certification environment. Refer to Ssection 8.8 for further details. 8.5

Welding consum ables

As with bolts, the majority of welding consumables are currently imported into Austra lia. The necessity to properly check certification is similar to that described in Section 8.4 for bolts, but it appears that the propensity for non-compliance is significantly less, based on the amount of feedback received from industry. The work of industry entities such as the Welding Technology Institute of Australia (WTIA) has helped to ensure standards are maintained in this important area. ASI has recent ly produced a Technical Note, TN008 ‘Welding consuma bles and design of welds in AS 410 0—1998 with amendment 1, 2012’ (Ref. 35) which discusses the effect of the rec ent harmonisation of weld consumables on the design of welds. 8.6

Product compl iance

The preceding sections have touched on some of the purely technical issues that provide the foundation for the need to ensure product compliance with internationally sourced material (and equally applicable to locally manufacturer material). Ref. 27 draws the distinction between two possible scenarios with regard to internationally sourced material: (a)

Material manufactured overseas and claiming to comply with one of the Australian Standards cited in Clause 2.2.1 of AS 4100;

(b)

Material manufactured overseas and claiming to comply with one or more overseas Standards.

For type (a) mater ial, Clause 2.2.2 of AS 4100 applies and a certificate indicatin g compliance to th e nominated Standard should be available in order to indicate full compliance. Engineers need to satisfy themselves as to the veracity of these compliance certificates, which should not always be assumed. For type (b) material, Reference 27 discusses the obligations placed on the designer and nominates five possible paths for ensuring compliance, in summary being one or other of: 1.

Obtain sufficient statistical data on the chemical and mechanical properties of the imported steels so that they can be assigned to one of the grades for the steels cited in Clause 2.2 of AS 4100.

2.

Obtain test certificates from the mill certifying that the steel intended to be used or being supplied complies with a ll r equirements of the relevant Standard, either AS/NZS 1163, AS/NZS 1594, AS/NZS 3678, AS/NZS 3679.1, AS/NZS 3679.2 or AS 359 7. Fully c ompliant test c ert ificates should be provided which meet the requirements of Clause 2.2.2 of AS 4100 (2012 amendment).


15


3.

Have sufficient tests done by an independent ILAC or APLAC accredited laboratory (all Australian NATA laboratories are ILAC accredited) under Clause 2.2.2 and obtain certification from the accredited laboratory to enable the steel to be fitted into a grade in the relevant Standard in terms of all parameters in the Standards. The question of what constitutes “sufficient tests” is discussed in Section 8.7.

4.

Treat the steel as unidentified steel as defined in Clause 2.2.3 of AS 4100, which requires the design yield stress of unidentified stee l to be down-r ated to not excee ding 170 MPa. This is a severe requirement and would usually prove uneconomic.

5.

Use a modified capacity factor Φ for the imported material, which would require carrying out statistical studies on sufficient product and its normal distribution in order to derive new capacity factors, design yield stress and tensile strength, using the code calibration approaches detailed in the references to the Commentary to AS 4100. This process would be very lengthy. Note that this does not address other non-strength related properties, such as ductility and weldability, which would still require separate assessment.

It should be obvious that none of these paths are trivial and all require a significant investment in time and resources to undertake properly. 8.7

Sample tests of impor ted produ ct

It is currently a common practice for one or a very small number of tests to be undertaken on imported product in order to obtain values of principal mechanical properties such as yield strength and ultimate tensile strength. However, a single or limited testing program does not establish the required statistical data to form the basis for the proper assessment of the necessary capacity factors and design yield strength, or the range of other mechanical or chemical properties required to establish compliance to the Standards, as noted above. At best, a single or limited testing regime may be used to confirm the veracity of product that has proper compliance documentation already in place. Single or limited test results cannot be used to change the grade of the steel. Only the steel manufacturer can determine the grade of the steel, based on the statistical data obtained from their in-process testing programs and the normal distribution of test results. A single test result represents a snapshot on that normal distribution curve and may only be used to verify against the proper compliant documentation that has been received with the product that the test result fits within the usual normal distribution expected for that product. Where such compliant documentation does not exist and therefore the steel is essentially ‘unidentified’, one of the five options noted in Section 8.6 must be undertaken. BS EN 1990:2002 ‘Basis of structural design’ (Ref. 36) provides a methodology in Appendix D – ‘Design assisted by testing’ for utilising testing programs for a range of scenarios, including two of immediate relevance to the current discussion: (A)

“Tests to obtain specific material properties using specified testing procedures; for instance, ground testing in situ or in the laboratory, or the testing of new materials”

(B)

“Control tests to check the identity or quality of delivered products or the consistency of production characteristics; for instance, testing of cables for bridges, or concrete cube testing”

Ref. 36 states that for test type A “the design values to be used should wherever practicable be derived from the test results by applying accepted statistical techniques”. Test type B “may be considered as acceptance tests where no test results are available at the time of design. Design values should be conservative estimates which are expected to be able to meet the acceptance criteria … at a later stage”. In essence, the difference between type A tests and type B tests lies in whether the testing samples come from a batch of product that is not well documented (and therefore ‘unidentified’) or from a batch of product that has proper compliance documentation, respectively. The type A testing regime relies on statistical processes with multiple samples in order to increase confidence in the product properties. Section D5 of Ref. 36 discusses derivation of the characteristic values from test data. Section D6 of Ref. 36 goes on to state: “The methods given in this Annex may be used only when the following conditions are satisfied: —the statistical data (including prior information) are taken from identif ied populations whic h are sufficiently homogeneous; and —a suffic ient n umber of observations is available.”

16


Whilst not precluding a single or limited tests, it is noted that: “where one test only (or very few tests) is (are) performed, no classical statistical interpretation is possible. Only the use of extensive prior information associated with hypotheses about the relative degrees of importance of this information and of the test results, make it possible to present an interpretation as statistical (Bayesian procedures, see ISO 12491)”. . k r o w t e n r u o y m o r f d e t e l e d e . b d t e s t u i b i m h n o r o i p t a e c r i l a b n u o p i t s u i h b i t r , t I s i S d A d e n h t a e m g o r a r f o n t g s i , s e e r s u y k n r a o p w t m o e c n r ; y u p o o y c d r l u e o p h a p S . e d n e o t t i s u l m r p e y p l s n i o r k r e t o u w t p e m n o r c u r o u y o n y o o t n o g i n t i u v b a i r s t s s i d w o r l o l a e e g c a r n o e t c s i l , e r s e u s u : l I S a A n o e s h r e t f p o r s u r o e y : b I m S e A m e e h t t f a r o o s p r r e o b c l m a e i c m n l a a n u i d F i . i v t h d g i n i r l y a p i o c c n I a n S i A F

Section D7 of Ref. 36 goes on to present expressions for the assessment of design values based on the number of tests and knowledge (or otherwise) about the expected coefficient of variation of the test results. This latter point addresses knowledge about the manufacturing processes and variability that may be obtained from the manufacturer. In the case of steel supply from the majority of reputable manufacturers, there should be little problem in obtaining sufficient statistical data to inform this process. In the case of bolt supply for example, the nature of the market is such that it may be difficult to obtain useful or reliable records. 8.8

Third-party produ ct certification

Non-compliant steel materials and products are a significant issue for the construction industry (as it is with other materials and industries), in particular with the changes in the supply environment and some significant shifting toward imported materials, products and services. Industry inertia, resistance to change and economic pressure have resulted in a dislocation between the supply side and the demand side, with ‘business as usual’ not keeping up with supply dynamics. The technical and resource demands for rigorous compliance policing are often beyond the capacity of product purchasers or users, who ideally should be able to rely on straightforward ‘trusted’ certification processes and deliverables. Within this context, the industry has and continues to evolve third-party certification schemes that provide purchasers with an assurance of quality product. Third-party product certification schemes such as that administered by the Australian Certification Authority for Reinforcing Steels (ACRS) (http://www.acrs.net.au/ or http://www.steelcertification.com/) have provided certification services for some time and have recently extended their range into structural steels. Other international certification authorities also exist and may be utilised. ASI recommends third-party certifie d product as an app ropriate solution to ens ure quality compliant and fitfor-purpose product, whether locally produced or imported, is used on all projects to help ensure that project stakeholders at all levels meet their duty of care responsibilities and legislated WH&S requirements. An ASI Technical Note on third-party steel product certification (Ref. 37) provides context to this recommendation. With third-party product certification in place, and with respect to enacting these responsibilities, the process then becomes relatively straightforward, including: •

•

9 9.1

The responsible parties obtain documentation of third-part y product compliance from the relevant certifying authority named on the product documentation received. This means more than simply accepting statements from product suppliers but active checking of these claims with the certification authority, the details of which may be conveniently recorded on the certifying authority website. The various stakeholders in the process ensure their documentation includes the necessary references to third-party certification requirements. This includes specifications, tender documents and engineering documentation. For example, the wording ASI currently recommends on engineering drawing notes is as follows: “ Struct ural steel s hall compl y with AS/NZS 1163, AS/NZS 3678, AS/NZS 3679.1 or AS/NZS 367 9.2. Accep tab le man ufac turer s of struct ural st eel must hold a valid certificate of approval issued by the appropriate certifying authority e.g. ACRS. Refer to www.steelcertification.com for current ACRS certification holders. Evidence of compliance to this clause must be made on tendering” .

DESIGN MODELS ADOPTED Basis

The basis for selecting the recommended design models is detailed in Sections 2.3 and 2.4 of Tubular Design Guide 20 (TDG 20). A detailed explanation of each recommended design model is contained in the relevant Tubular Design Guide. The design models meet the requirements of AS 4100 by providing a rational and recognised design model for a range of common steel tubular connections, the design models in each design guide reflecting engineering principles and known connection behaviour from experimental data. The emphasis in all STEEL CONSTRUCTION VOLUME 46 NUMBER 2 – MARCH 2014

17


publications is on practical design models whose assumptions are transparent to the user, backed up with substantial historical and current reference. The design models are related to current Australian Standards in respect of member and fastener design and member and fastener mechanical properties, which are presented in TDG 20. The philosophy of each Design Guide is the same as that described in Handbook 1 (Ref. 38), being: •

•

•

Take into account overall connection behaviour and carry out an approximate analysis in order to determine a realistic distribution of forces within the connection. Ensure that each component or fastener or section face in each action path has sufficient capacity to transmit the applied actions, and Recognise that this procedure can only give a connection where equilibrium is capable of being achieved but where compatibility is unlikely to be satisfied and therefore ensure that the connection elements are capable of ductile behaviour if so required.

The design models contained within the Design Guides are considered to be applicable only to connections which are essentially statically loaded. Connections subjected to dynamic loads, earthquake loads or fatigue applications may require additional considerations. The following sections outline the essential features of each design model included in the current Tubular Connection Series. 9.2

Slott ed SSHS end con nectio n (TDG 21)

The slotted SSHS end connection comprises a length of plate or flat bar that is slotted into the end of an SSHS member and fillet welded on both sides to the SSHS member i.e. four fillet weld runs. Refer to Figure 4 for typical examples of the connection. The end of the member may be either sealed with end plates or left open. This cleat plate connection is then connected with bolts to a supporting member, usually through another cleat or gusset plate welded to the supporting member. The supporting member may be an SSHS member or an open section such as an I-beam or channel section.

FIGURE 4

TYPICAL SLOTTED SSHS END CONNECTION CONFIGURATIONS

Features of the connection are: — Welds are fillet we lds to both sides of the cleat plate, con necting i t to the member — The cleat plate is either a standard size flat bar or a plat e cut to suit — The bolting category used is normally 8 .8/S — The end of the SSHS member may optionall y be closed with seal plates if architectural or functional requirements dictate. Seal plates are not considered to contribute to the structural performance of the connection and are hence not featured in the design models subsequently discussed.

18


The main focus of this design model is the isolated end connection for a single brace member. Design models specific to a connection assembly, comprising the cleat plate on the member bolted to a bracing cleat or gusset plate on the supporting member, are provided in Tubular Design Guide 22. . k r o w t e n r u o y m o r f d e t e l e d e . b d t e s t u i b i m h n o r o i p t a e c r i l a b n u o p i t s u i h b i t r , t I s i S d A d e n h t a e m g o r a r f o n t g s i , s e e r s u y k n r a o p w t m o e c n r ; y u p o o y c d r l u e o p h a p S . e d n e o t t i s u l m r p e y p l s n i o r k r e t o u w t p e m n o r c u r o u y o n y o o t n o g i n t i u v b a i r s t s s i d w o r l o l a e e g c a r n o e t c s i l , e r s e u s u : l I S a A n o e s h r e t f p o r s u r o e y : b I m S e A m e e h t t f a r o o s p r r e o b c l m a e i c m n l a a n u i d F i . i v t h d g i n i r l y a p i o c c n I a n S i A F

Summary of design checks: General DESIGN CHECK NO. 1

— Detailing requirements

DESIGN CHECK NO. 2

— Validity limits and minimum design actions

Axial tensio n DESIGN CHECK NO. 3

— Design capacity of bolts in shear and ply bearing

DESIGN CHECK NO. 4

— Design capacity of welds to SSHS member

DESIGN CHECK NO. 5

— Design capacity due to end plate tearout in cleat plate

DESIGN CHECK NO. 6

— Design capacity of cleat plate in block shear

DESIGN CHECK NO. 7

— Design capacity of cleat plate in axial tension

DESIGN CHECK NO. 8

— Design capacity of cleat plate due to shear lag

DESIGN CHECK NO. 9

— Design capacity of SSHS member locally

Axial compression DESIGN CHECK NO. 10 — Design capacity of bolts in shear and ply bearing DESIGN CHECK NO. 11 — Design capacity of welds to SSHS member DESIGN CHECK NO. 12 — Design capacity of cleat plate due to shear lag DESIGN CHECK NO. 13 — Design capacity of SSHS member locally DESIGN CHECK NO. 14 — Design capacity of cleat plate under eccentric compression force

As well as a worked example, the following Des ign Capacity Tables are provided with this des ign model, derived using the Design Checks stated above: Table

Member type

Grade (MPa)

Design actions

3.13.1(a)

CHS – ‘small’

250

tension; compression

3.13.1(b)

CHS – ‘large’

250


3.13.2(a)

CHS – ‘small’

350


3.13.2(b)

CHS – ‘large’

350


3.13.3(a)

SHS – ‘small’

350


3.13.3(b)

SHS – ‘large’

350


3.13.4(a)

SHS – ‘small’

450


3.13.4(b)

SHS – ‘large’

450


3.13.5(a)

RHS – ‘small’

350


3.13.5(b)

RHS – ‘large’

350


3.13.6(a)

RHS – ‘small’

450


3.13.6(b)

RHS – ‘large’

450



19

9.3


Welded tee SSHS end con necti on (TDG 21)

The welded tee SSHS end connection comprises a length of plate or flat bar that is welded transversely onto a cap plate which in turn is welded onto the end of an SSHS member (refer to Figure 5 for typical examples of the connection). The cleat plate connection is then connected with bolts to a supporting member, usually through another cleat or gusset plate welded to the supporting member. The supporting member may be an SSHS member or an open section such as an I-beam or channel section.

FIGURE 5

TYPICAL WELDED TEE END CONNECTION CONFIGURATIONS

Features of the connection are: — Welds are fillet we lds to both sides of the cleat plate, con necting it to the cap plate — The cleat plate is either a stan dard size fla t bar or a plat e cut to suit — The cap plate is welded all round to the square cut end of the SSHS with either fillet welds or a butt weld — The cap plate is either a standar d size flat bar or a plate cut to suit — The bolting category used is normally 8 .8/S The main focus of this design model is the isolated single tee SSHS end connection for a brace member. Design models specific to a connection assembly, comprising the cleat plate on the member bolted to a bracing cleat or gusset plate on the connected member, are provided in Tubular Design Guide 22. Summary of design checks: General DESIGN CHECK NO. 1


DESIGN CHECK NO. 2




DESIGN CHECK NO. 4

— Design capacity of welds of cleat plate to cap plate

DESIGN CHECK NO. 5

— Design capacity due to end plate tearout in cleat plate

20



DESIGN CHECK NO. 6

— Design capacity of cleat plate in block shear

DESIGN CHECK NO. 7

— Design capacity of cleat plate in axial tension

DESIGN CHECK NO. 8

— Design capacity of cap plate due to punching shear

DESIGN CHECK NO. 9

— Design capacity of cap plate due to plastic hinge formation (cap + tube walls)

DESIGN CHECK NO. 10 — Design capacity of cap plate due to plastic hinge formation (cap only) DESIGN CHECK NO. 11 — Design capacity of welds of cap plate to SSHS DESIGN CHECK NO. 12 — Design capacity of SSHS wall – local yielding

Axial compression DESIGN CHECK NO. 13 — Design capacity of bolts in shear and ply bearing DESIGN CHECK NO. 14 — Design capacity of welds of cleat plate to cap plate DESIGN CHECK NO. 15 — Design capacity of welds of cap plate to SSHS DESIGN CHECK NO. 16 — Design capacity of SSHS wall—local yielding DESIGN CHECK NO. 17 — Design capacity of SSHS wall—local crippling DESIGN CHECK NO. 18 — Design capacity of end plate under eccentric compression force As well as a worked example, the following Des ign Capacity Tab les are provided with this design model, derived using the Design Checks stated above: Table

Member type

Grade (MPa)

Design actions

4.13.1(a)

CHS – ‘small’

250


4.13.1(b)

CHS – ‘large’

250


4.13.2(a)

CHS – ‘small’

350


4.13.2(b)

CHS – ‘large’

350


4.13.3(a)

SHS – ‘small’

350


4.13.3(b)

SHS – ‘large’

350


4.13.4(a)

SHS – ‘small’

450


4.13.4(b)

SHS – ‘large’

450


4.13.5(a)

RHS – ‘small’

350


4.13.5(b)

RHS – ‘large’

350


4.13.6(a)

RHS – ‘small’

450


4.13.6(b)

RHS – ‘large’

450



21

9.4


Flattened end CHS conn ection (TDG 21)

(a) Bolted

FIGURE 6

(b) End cropped

TYPICAL FLATTENED END CHS CONFIGURATIONS

The flattened end CHS connection comprises a CHS bracing member which has the end flattened over a defined length and that flattened length holed to take connection bolts (refer to Figure 6 for typical examples of the connection). The flattened end is then connected with bolts to a supporting member, usually through a cleat or gusset plate welded to the supporting member. The supporting member may be an SSHS member or an open section such as an I or channel section. In some cases the end of the flattened area may be directly welded to the supporting member or to a cleat or gusset rather than bolted. Features of the connection are: — The width of the flattened end is predominantly a function of the diameter of the CHS bracing member. — Flattening is undertaken until the opp osite fac es of the CHS are approximately tou ching each other. — The bolting category used is normally 8 .8/S. The main focus of this design model is the isolated end flattened connection at the end of the brace member. Design models specific to a connection assembly, comprising the end flattening on the brace member bolted to a cleat plate or gusset plate on the supporting member, are also presented, related back to the cleat plate assembly detailed in Tubular Design Guide 22. Summary of design checks: General DESIGN CHECK NO. 1 — Detailing requirements DESIGN CHECK NO. 2 — Validity limits and minimum design actions

Axial tensio n DESIGN CHECK NO. 3 — Design capacity of bolts in shear and ply bearing DESIGN CHECK NO. 4 — Design capacity due to end plate tearout in flattened end DESIGN CHECK NO. 5 — Design capacity of flattened end in block shear DESIGN CHECK NO. 6 — Design capacity of flattened end in axial tension

22


Axial compression DESIGN CHECK NO. 7 — Design capacity of bolts in shear and ply bearing . k r o w t e n r u o y m o r f d e t e l e d e . b d t e s t u i b i m h n o r o i p t a e c r i l a b n u o p i t s u i h b i t r , t I s i S d A d e n h t a e m g o r a r f o n t g s i , s e e r s u y k n r a o p w t m o e c n r ; y u p o o y c d r l u e o p h a p S . e d n e o t t i s u l m r p e y p l s n i o r k r e t o u w t p e m n o r c u r o u y o n y o o t n o g i n t i u v b a i r s t s s i d w o r l o l a e e g c a r n o e t c s i l , e r s e u s u : l I S a A n o e s h r e t f p o r s u r o e y : b I m S e A m e e h t t f a r o o s p r r e o b c l m a e i c m n l a a n u i d F i . i v t h d g i n i r l y a p i o c c n I a n S i A F

DESIGN CHECK NO. 8 — Design capacity of flattened end under eccentric compression force As well as a worked example, the following Des ign Capacity Tables are provided with this des ign model, derived using the Design Checks stated above:

9.5

Table

Member type

Grade (MPa)

Design actions

5.13.1

CHS

250


5.13.2

CHS

350


Braci ng cleat (TDG 22)

FIGURE 7

CONFIGURATION OF BRACING CLEAT

The isolated bracing cleat connection comprises a length of plate or flat bar that is fillet welded on both sides to the SSHS supporting member (refer to Figure 7 for typical examples of the connection), usually aligned with the longitudinal axis of the supporting member. The bracing cleat is usually connected with bolts to a bracing member that is acting under tensile or compressive load. Features of the connection are: — Welds are fillet welds to bot h sides of the bracing cle at, connecting it to the fac e of the suppor ting member — The bracin g cleat is either a standard size f lat bar or a plat e cut to suit — The bolting category used is normally 8 .8/S — The bracin g cleat is usuall y aligne d with the long itudinal axis of the supportin g member and positioned centrally on the face — The bracin g cleat is aligned with the bracin g member at an angle to the longitudi nal axis of the supporting member The main focus of this design model is the isolated bracing cleat connected to a single brace member. Design models specific to a connection assembly, comprising the bracing cleat on the supporting member bolted to a cleat on the supported member, are provided in Tubular Design Guide 22. Design models specific to multiple bracing members framing into a single bracing cleat, which in the terminology of these design guides is called a ‘gusset plate’, are also provided in Tubular Design Guide 22. STEEL CONSTRUCTION VOLUME 46 NUMBER 2 – MARCH 2014

23

Summary of design checks: General . k r o w t e n r u o y m o r f d e t e l e d e . b d t e s t u i b i m h n o r o i p t a e c r i l a b n u o p i t s u i h b i t r , t I s i S d A d e n h t a e m g o r a r f o n t g s i , s e e r s u y k n r a o p w t m o e c n r ; y u p o o y c d r l u e o p h a p S . e d n e o t t i s u l m r p e y p l s n i o r k r e t o u w t p e m n o r c u r o u y o n y o o t n o g i n t i u v b a i r s t s s i d w o r l o l a e e g c a r n o e t c s i l , e r s e u s u : l I S a A n o e s h r e t f p o r s u r o e y : b I m S e A m e e h t t f a r o o s p r r e o b c l m a e i c m n l a a n u i d F i . i v t h d g i n i r l y a p i o c c n I a n S i A F

DESIGN CHECK NO. 1


DESIGN CHECK NO. 2

— Validity limits and minimum



DESIGN CHECK NO. 4

— Design capacity due to end plate tearout in end plate

DESIGN CHECK NO. 5

— Design capacity of bracing cleat in block shear

DESIGN CHECK NO. 6

— Design capacity of bracing cleat in axial tension

DESIGN CHECK NO. 7

— Design capacity of weld to SSHS member

DESIGN CHECK NO. 8

— Design capacity of SSHS member locally – local shear

DESIGN CHECK NO. 9

— Design capacity of SSHS member locally – face yielding

Axial compression DESIGN CHECK NO. 10 — Design capacity of bolts in shear and ply bearing DESIGN CHECK NO. 11 — Design capacity of weld to SSHS member DESIGN CHECK NO. 12 — Des ign capacity of SSHS member locally – local shear DESIGN CHECK NO. 13 — Design capacity of SSHS member locally – face yielding DESIGN CHECK NO. 14 — Design capacity of bracing cleat under eccentric compression force As well as a worked example, the following Des ign Capacity Tables are provided with this des ign model, derived using the Design Checks stated above:

24

Table

Member type

Grade (MPa)

Design actions

3.13.1(a)

CHS – ‘small’

250

compression / tension

3.13.1(b)

CHS – ‘large’

250


3.13.2(a)

CHS – ‘small’

350


3.13.2(b)

CHS – ‘large’

350


3.13.3(a)

SHS – ‘small’

350


3.13.3(b)

SHS – ‘large’

350


3.13.4(a)

SHS – ‘small’

450


3.13.4(b)

SHS – ‘large’

450


3.13.5(a)

RHS – ‘small’

350


3.13.5(b)

RHS – ‘large’

350


3.13.6(a)

RHS – ‘small’

450


3.13.6(b)

RHS – ‘large’

450



9.6


Guss et pl ate (TDG 22)

FIGURE 8

TYPICAL CONFIGURATIONS OF GUSSET PLATES

The gusset plate connection comprises a plate or flat bar component that is fillet welded all around to the SSHS supporting member (refer to Figure 8 for typical examples of the connection) and usually aligned with the longitudinal axis of the supporting member. The gusset plate is designed to accept one or more bracing member cleat plates bolted to it in a configuration that provides load transfer between multiple members inplane whilst at the same time ensuring adequate clearance. The bracing members are usually acting under tensile or compressive load. The gusset plate is structurally similar to the isolated bracing cleat detailed in Section 3 except that since it is usually larger to accommodate one or more bracing member cleat connections, the area of bracing cleat contributing to the load capacity associated with each bracing cleat connection is not as well defined. Features of the connection are: — Welds are fillet welds to bot h sides of the gusset pla te, con necting it to the fac e of the supporting member. — The gusset plate is usually a plate cut to suit. Given the variation in sizes of gusset plates to suit bracing configurations, it is usually not practical to cut gusset plates from flat bar. — The bolting category used is normally 8 .8/S. — The gusset plate is usuall y aligne d with the lon gitudinal axis of the supporting member and positioned centrally on the face of the SSHS (with or without any small offset to account for plate thicknesses of the gusset or cleats on the bracing members). — The gusset pla te shape is config ured to the ang ular alignme nt of the bracing members framing into the connection and the necessary clearances. The main focus of the gusset plate model is the gusset plate with connections to single or multiple bracing members and welded to the face of the supporting member. Design models specific to a connection assembly, comprising the cleat plate on the brace member bolted to the gusset plate on the supporting member, are provided in Tubular Design Guide 22. STEEL CONSTRUCTION VOLUME 46 NUMBER 2 – MARCH 2014

25

Summary of design checks: General . k r o w t e n r u o y m o r f d e t e l e d e . b d t e s t u i b i m h n o r o i p t a e c r i l a b n u o p i t s u i h b i t r , t I s i S d A d e n h t a e m g o r a r f o n t g s i , s e e r s u y k n r a o p w t m o e c n r ; y u p o o y c d r l u e o p h a p S . e d n e o t t i s u l m r p e y p l s n i o r k r e t o u w t p e m n o r c u r o u y o n y o o t n o g i n t i u v b a i r s t s s i d w o r l o l a e e g c a r n o e t c s i l , e r s e u s u : l I S a A n o e s h r e t f p o r s u r o e y : b I m S e A m e e h t t f a r o o s p r r e o b c l m a e i c m n l a a n u i d F i . i v t h d g i n i r l y a p i o c c n I a n S i A F

DESIGN CHECK NO. 1


DESIGN CHECK NO. 2



— Design capacity of bolts in shear and bearing

DESIGN CHECK NO. 4

— Design capacity due to end plate tearout in gusset plate

DESIGN CHECK NO. 5

— Design capacity of gusset plate in block shear

DESIGN CHECK NO. 6

— Design capacity of gusset plate in axial tension

Axial compression DESIGN CHECK NO. 7


DESIGN CHECK NO. 8

— Design capacity of gusset plate under eccentric compression force

Net connection forces (tension or compression) DESIGN CHECK NO. 9

— Design capacity of gusset plate – section yield

DESIGN CHECK NO. 10 — Design capacity of weld to SSHS supporting member DESIGN CHECK NO. 11 — Design capacity of SSHS member locally – local shear DESIGN CHECK NO. 12 — Design capacity of SSHS member locally – chord face yielding DESIGN CHECK NO. 13 — Design capacity of SSHS member locally – punching shear The range of variables and number of different geometric configurations of gusset plate connections make it difficult to rationalise a meaningful set of design capacity tables (DCT). However, the particular gusset plate configuration can be broken down into component failure groupings and the design capacity tables documented for the relevant design models used to find an approximate solution. Specifically: 1.

Assess the local bolted connection related tension failure modes using the results for one of the cleat connection types, such as slotted end plate or welded tee end. In most cases these will provide a conservative (i.e. lower) estimate of capacity since the extent and edge distances of the gusset plate may be larger than the cleat connection used in these DCTs.

2.

Assess the eccentric compression failure load using the results in Tubular Design Guide 22 for cleat assemblies. These DCTs address only the compression capacity of the cleat assembly and have been in part configured to model the Whitmore section for one of the two cleats, thereby being applicable to the connection of a cleat to a gusset plate.

3.

Assess the net gusset plate failure modes utilising the DCTs for the moment side plate connection given in Tubular Design Guide 23. These require the net forces on the gusset plate, which will need to be resolved from the component forces in each member framing into the gusset plate.

26


9.7


Cleat plate assembly (TDG 22)

(a) Single brace connection

(b) Gusset plate connection

(c) Cleat assembly

(d) Whitmore section calculation

FIGURE 9

TYPICAL CONFIGURATIONS OF CLEAT PLATE ASSEMBLIES

The cleat plate assembly comprises a cleat plate on the brace member bolted to a cleat plate on the supporting member, as shown in Figure 9(a) and (c). A cleat plate on a member bolted to a gusset plate on the supporting member, as shown in Figure 9(b), is also considered a cleat plate assembly, where an effective width of the gusset plate, known as the ‘Whitmore section’ is used to model an equivalent cleat plate attached to the support, as shown in Fig. 9(d). Features of the connection are: — Welds are usually fillet weld s to the brace member and to the supporting member. — The cleat plates (or gusset plate) may be either a sta ndar d size flat bar or a pla te cut to suit. For the gusset plate it may be difficult to source flat bar of the required dimensions. — The bolting category used is normally 8 .8/S. — The cleat plates are usuall y aligned with the longitudinal axis of the members and positioned centrally on the respective member faces. The main focus of the model is the cleat plate assembly comprising single cleat plate on the bracing member bolted to a single cleat plate connected to the supporting member. The design checks relevant only to compression stability are presented. Design checks related to all other failure modes, such as bolt bearing and tearout, plate tearout and block shear are described adequately in other connection models in the Tubular Connection Series, for example, the slotted end SSHS connection.


27

The cleat plate assembly model is presented in a generic form as two separate cleat plates, each with their own width, thickness, length and material properties, as shown in Fig. 10. Subscript ‘I’ in Fig. 10 refers to properties related to the cleat plate welded to the supported (brace) member, whilst subscript ‘j’ refers to properties related to the cleat or gusset plate welded to the supporting member. . k r o w t e n r u o y m o r f d e t e l e d e . b d t e s t u i b i m h n o r o i p t a e c r i l a b n u o p i t s u i h b i t r , t I s i S d A d e n h t a e m g o r a r f o n t g s i , s e e r s u y k n r a o p w t m o e c n r ; y u p o o y c d r l u e o p h a p S . e d n e o t t i s u l m r p e y p l s n i o r k r e t o u w t p e m n o r c u r o u y o n y o o t n o g i n t i u v b a i r s t s s i d w o r l o l a e e g c a r n o e t c s i l , e r s e u s u : l I S a A n o e s h r e t f p o r s u r o e y : b I m S e A m e e h t t f a r o o s p r r e o b c l m a e i c m n l a a n u i d F i . i v t h d g i n i r l y a p i o c c n I a n S i A F

Figure 10 also illustrates a cleat connected to a gusset plate, where the gusset plate properties are based on the ‘Whitmore Section’. The generic bolted cleat plate assembly presented in this section may be used to assess the compression capacity of the cleat to gusset connection, where the gusset is treated as a cleat with the equivalent Whitmore section.

FIGURE 10

GENERIC CLEAT PLATE ASSEMBLY AND MODELLING OF CLEAT-TO-GUSSET CONNECTION

Summary of design checks: General DESIGN CHECK NO. 1 — Detailing requirements DESIGN CHECK NO. 2 — Validity limits and minimum design actions

Axial compression DESIGN CHECK NO. 3 — Design capacity compression force

of

cleat

plate

assembly

under

eccentric

As well as a worked example, the following Des ign Capacity Tables are provided with this des ign model, derived using the Design Checks stated above: Table

28

Cleat thickness (mm)

Member type

Design action

5.13.1(a)

‘small’ cleat assembly

8, 10, 12

compression

5.13.1(b)

‘large’ cleat assembly

10, 12, 16, 20

compression

5.13.2(a)

‘small’ cleat assembly

8, 10, 12

tension

5.13.2(b)

‘large’ cleat assembly

10, 12, 16, 20

tension


9.8


Web si de pl ate (TDG 23)

(a) Web side plate to CHS

FIGURE 11

(b) Web side plate to SHS

TYPICAL WEB SIDE PLATE CONFIGURATIONS

The web side plate connection consists of a length of plate or flat bar, fillet welded on both sides to the supporting SSHS member, with bolts connecting the supported member (often a beam web) to the web side plate (refer to Figure 11 for typical examples of the connection). Features of the connection are: — Welds are fillet welds to bot h sid es of the cleat compon ent, connecting it to the supportin g member — The cleat component is either a standard size fla t bar or a plate cut to suit — The bolting category norm ally used is 8.8/S — The connection can be used with ske w support ed members, as shown in Fig. 1 1(b). The main focus of this model is the isolated web side plate connected to an SSHS member. Hence design checks are presented only for the connection plate and SSHS components. Design models specific to the supported member (often an I-beam) are provided in ASI Connection Design Guide 3 (included in Ref 1). Summary of design checks: DESIGN CHECK NO. 1


DESIGN CHECK NO. 2


DESIGN CHECK NO. 3


DESIGN CHECK NO. 4


DESIGN CHECK NO. 5

— Design capacity of web side plate in shear

DESIGN CHECK NO. 6

— Design capacity of web side plate in block shear

DESIGN CHECK NO. 7

— Design capacity of web side plate in bending

DESIGN CHECK NO. 8

— Design capacity of SSHS member—local shear

DESIGN CHECK NO. 9

— Design capacity of SSHS member—punching shear

DESIGN CHECK NO. 10 — Design capacity of SSHS member—face yielding


29

As well as a worked example, the following Des ign Capacity Tables are provided with this des ign model, derived using the Design Checks stated above:


9.9

Table

Member type

Grade (MPa)

Bolt lines (n g )

3.13.1(a)

CHS – ‘small’

250

1, 2

3.13.1(b)

CHS – ‘large’

250

1

3.13.1(c)

CHS – ‘large’

250

2

3.13.2(a)

CHS – ‘small’

350

1, 2

3.13.2(b)

CHS – ‘large’

350

1

3.13.2(c)

CHS – ‘large’

350

2

3.13.3(a)

SHS – ‘small’

350

1, 2

3.13.3(b)

SHS – ‘large’

350

1

3.13.3(c)

SHS – ‘large’

350

2

3.13.4(a)

SHS – ‘small’

450

1, 2

3.13.4(b)

SHS – ‘large’

450

1

3.13.4(c)

SHS – ‘large’

450

2

3.13.5(a)

RHS – ‘small’

350

1, 2

3.13.5(b)

RHS – ‘large’

350

1

3.13.5(c)

RHS – ‘large’

350

2

3.13.6(a)

RHS – ‘small’

450

1, 2

3.13.6(b)

RHS – ‘large’

450

1

3.13.6(b)

RHS – ‘large’

450

2

Moment sid e plate (TDG 23)

FIGURE 12

30

TYPICAL MOMENT SIDE PLATE CONFIGURATIONS FOR SSHS SECTIONS



The moment side plate connection comprises a length of plate or flat bar that is welded to the side face of a CHS or SHS/RHS member aligned with the longitudinal axis of the member and, in the case of the SHS/RHS, usually centrally located on the face of the member. The plate is fillet welded on both sides to the SSHS member (refer to Fig. 12 for typical examples of the connection). This moment side plate connection is then usually connected via bolts or welds to other members. Typical applications might include cases of truss chord to brace connections where the brace member spacing or noding of the connection produces moment in the plane of the plate on the interface with the SSHS member. Features of the connection are: — Welds are fillet we lds to both sides of the moment side p late, connecting it to the member — The side plate is e ither a s tandar d size flat bar or a plate cut to suit — The bolting category use d is normally 8.8 /S, but may also be 8.8 /T where a sin gle member is connected to the side plate and intended to transfer moment. The main focus of this model is the isolated moment side plate connected to an SSHS member. Hence design checks are presented only for the connection plate and SSHS components. Design models related to the bolted connection of brace members to the plate are provided in Tubular Design Guide 22.

Summary of design checks: Net connection forces: DESIGN CHECK NO. 1 — Detailing requirements DESIGN CHECK NO. 2 — Validity limits and minimum design actions DESIGN CHECK NO. 3 — Design capacity of welds to SSHS member DESIGN CHECK NO. 4 — Design capacity of SSHS member locally—chord face yielding DESIGN CHECK NO. 5 — Design capacity of SSHS member locally—punching shear DESIGN CHECK NO. 6 — Design capacity of SSHS member locally—face shear DESIGN CHECK NO. 7 — Design capacity of side plate—section yield As well as a worked example, the following Des ign Capacity Tables are provided with this design model, derived using the Design Checks stated above: Table

Member type

Grade

Design action

4.13.1

CHS

250

moment

4.13.2

CHS

350

moment

4.13.3

SHS

350

moment

4.13.4

SHS

450

moment

4.13.5

RHS

350

moment

4.13.6

RHS

450

moment


31

9.10


Trans vers e pl ate (TDG 23)

FIGURE 13

TYPICAL TRANSVERSE PLATE CONFIGURATIONS FOR SSHS

The isolated transverse plate connection comprises a length of plate or flat bar that is fillet welded on both sides to the SSHS supporting member (refer to Figure 13 for typical examples of the connection), in a direction transverse to the longitudinal axis of the SSHS member. The transverse plate may be connected with bolts to a bracing member that is acting under tensile or compressive load. Features of the connection are: — Welds are fillet welds to bot h sides of the tra nsve rse plate, con necting it to the face of the supporting member. — The transverse plate is either a standard size f lat bar or a p late cut to suit. — The bolting category used (where bolts are required) is normally 8.8 /S. — The plate is aligned tra nsverse to the longitudinal axis of the supporting member and positione d centrally on the face. — The plate may be at an angle other than 90° to the longit udinal axis of the SSHS member. The main focus of this model is the isolated transverse plate intended to connect to a single brace member. Design models relevant to a connection assembly, comprising the transverse plate on the SSHS member bolted to a cleat on the supported brace member, are provided in Tubular Design Guide 22. Whilst bolted connection details may be indicated in some diagrams, this is purely for context. Where a bolted connection is made to a transverse plate, the relevant connection models as provided in TDG 22 should be referenced for the additional design checks necessary.

Summary of design checks: The design checks presented for this design model relate to the unique aspects of this connection type, primarily the action of the plate on the SSHS member to which it is connected. Where the plate is used as a bracing cleat with a bolted connection, additional checks for plate capacity are required. Appropriate checks for the plate acting as a bracing cleat are given in Tubular Design Guide 22.

32


General


DESIGN CHECK NO. 1


DESIGN CHECK NO. 2



— Design capacity of transverse plate in axial tension (effective width)

DESIGN CHECK NO. 4


DESIGN CHECK NO. 5

— Design capacity of SSHS member locally—face yielding

DESIGN CHECK NO. 6

— Design capacity of SSHS member locally—face punching shear

DESIGN CHECK NO. 7

— Design capacity of SSHS member locally—chord side wall failure

Axial compression DESIGN CHECK NO. 8

— Design capacity of transverse plate in axial compression (effective width)

DESIGN CHECK NO. 9


DESIGN CHECK NO. 10 — Design capacity of SSHS member locally—face yielding DESIGN CHECK NO. 11 — Design capacity of SSHS member locally—face punching shear DESIGN CHECK NO. 12 — Design capacity of SSHS member locally—chord side wall failure As well as a worked example, the following Des ign Capacity Tables are provided with this des ign model, derived using the Design Checks stated above: Table

Member type

Grade

Design action

5.13.1(a)

CHS

250

tension

5.13.1(b)

CHS

250

compression

5.13.2(a)

CHS

350

tension

5.13.2(b)

CHS

350

compression

5.13.3(a)

SHS

350

tension

5.13.3(b)

SHS

350

compression

5.13.4(a)

SHS

450

tension

5.13.4(b)

SHS

450

compression

5.13.5(a)

RHS

350

tension

5.13.5(b)

RHS

350

compression

5.13.6(a)

RHS

450

tension

5.13.6(b)

RHS

450

compression


33

9.11


Bol ted end plate spl ice (TDG 24)

FIGURE 14

TYPICAL BOLTED END PLATE SPLICE CONNECTION CONFIGURATIONS

The bolted end plate splice connection comprises a plate that is usually fillet welded across the end of an SSHS member, in most instances normal to the longitudinal axis of the SSHS member (refer to Figure 14 for typical examples of the connection). The end plate connection is then connected with bolts to a similarly prepared member (in the case of a splice connection between members) or may be bolted in a number of other configurations, usually through another plate welded to the other member. Some typical connection assemblies are shown in Figure 15. Features of the connection are: — Welds are usually fillet weld s all around the fla nge plate, connecting it to the member, alt hough where fillet welds over 8-10 mm are required, it may be more economical to use partial or full penetration butt welds. — The end plate is usually a plate cut to suit. — The bolting category used is normally 8 .8/TB. — The end plate is assumed to be uniform and continuou s i.e. solid, with the member butted onto one face of the plate. So-called ‘ring flanges’, where the plate has a hole to accept the member slotted into it, or that have a significant hole aligned with the longitudinal axis of the member, are not covered in this design guidance. Ring flanges are typically very thick, as the plate is designed to remain elastic, whereas solid flange plates can be designed for plastic behaviour in structural applications and are usually much thinner. Ring flanges would usually be required for cases where the SSHS member is fluid filled or intended to be concrete filled. The design models presented in this Guide are not applicable to ring flanges. — For the cas e of axial comp ression in the connection, it is assumed t hat the members on each s ide of the connection end plates are of similar size such that there are no through thickness bending or shearing effects caused by lack of direct bearing load paths through the thickness of the connection.

34



FIGURE 15

TYPICAL CONNECTION ASSEMBLIES UTILISING BOLTED END PLATES

The bolted end plate splice is designed to resist predominantly axial tension. Where present, applied moment is assumed to be sufficiently small such that the combined axial tension and moment does not result in any net compression around the connection. The scope of the model also includes axial compression, although the design checks for this case are trivial. Where bending moments are significant, the bolted moment end plate design model described in the following section should be adopted.

Summary of design checks: General DESIGN CHECK NO. 1 — Det ailing requirements DESIGN CHECK NO. 2 — Validity limits and minimum design actions

Axial tensio n DESIGN CHECK NO. 3 — Des ign cap acity of bolts in axial tension DESIGN CHECK NO. 4 — Des ign cap acity of welds to SSHS memb er DESIGN CHECK NO. 5 — Des ign cap acity of end plate in ben ding DESIGN CHECK NO. 6 — Des ign cap acity due to local yieldin g of SSHS member

Axial compression DESIGN CHECK NO. 7 — Des ign cap acity of welds to SSHS member


35

Axial tensio n and bending DESIGN CHECK NO. 8 — Des ign cap acity of bolts in axial tension DESIGN CHECK NO. 9 — Des ign cap acity of welds to SSHS member . k r o w t e n r u o y m o r f d e t e l e d e . b d t e s t u i b i m h n o r o i p t a e c r i l a b n u o p i t s u i h b i t r , t I s i S d A d e n h t a e m g o r a r f o n t g s i , s e e r s u y k n r a o p w t m o e c n r ; y u p o o y c d r l u e o p h a p S . e d n e o t t i s u l m r p e y p l s n i o r k r e t o u w t p e m n o r c u r o u y o n y o o t n o g i n t i u v b a i r s t s s i d w o r l o l a e e g c a r n o e t c s i l , e r s e u s u : l I S a A n o e s h r e t f p o r s u r o e y : b I m S e A m e e h t t f a r o o s p r r e o b c l m a e i c m n l a a n u i d F i . i v t h d g i n i r l y a p i o c c n I a n S i A F

DESIGN CHECK NO. 10 — Des ign cap acity of end plate in ben ding DESIGN CHECK NO. 11 — Des ign cap acity due to local yielding of SSHS member As well as a worked example, the following Des ign Capacity Tables are provided with this des ign model, derived using the Design Checks stated above:

Table

End plate type

Member type

End plate grade (MPa)

3.13.1(a)

circular

CHS Grade 250

250

axial tension

50%

3.13.1(b)

circular

CHS Grade 250

250

axial tension

100%

3.13.2(a)

circular

CHS Grade 350

250

axial tension

50%

3.13.2(b)

circular

CHS Grade 350

250

axial tension

100%

3.13.3

rectangular 2 sided

SHS Grade 350

250

axial tension

50%

3.13.4

rectangular 2 sided

RHS Grade 350

250

axial tension

50%

3.13.5

rectangular 2 sided

SHS Grade 450

350

axial tension

50%

3.13.6

rectangular 2 sided

RHS Grade 450

350

axial tension

50%

3.13.7(a)

rectangular 4 sided

SHS Grade 350

250

axial tension

50%

3.13.7(b)

rectangular 4 sided

SHS Grade 350

250

axial tension

100%

3.13.8(a)

rectangular 4 sided

RHS Grade 350

250

axial tension

50%

3.13.8(b)

rectangular 4 sided

RHS Grade 350

250

axial tension

100%

3.13.9(a)

rectangular 4 sided

SHS Grade 450

350

axial tension

50%

3.13.9(b)

rectangular 4 sided

SHS Grade 450

350

axial tension

100%

3.13.10(a)

rectangular 4 sided

RHS Grade 450

350

axial tension

50%

3.13.10(b)

rectangular 4 sided

RHS Grade 450

350

axial tension

100%

36

Design action

Capacity (refer Not e 1)


9.12


Bol ted mom ent end plate (TDG 24)

(a) Four bolt connection

FIGURE 16

(b) Eight bolt connection

TYPICAL BOLTED MOMENT END PLATE CONNECTION CONFIGURATIONS

The bolted moment end plate connection comprises a solid plate that is welded across the end of an SHS/RHS member, usually normal to the longitudinal axis of the member (refer to Figure 16 for typical examples of the connection). This member end plate connection is then usually connected with bolts to a similarly prepared plate welded to another member. Features of the connection are: — The design mod el adopted is based on tests in which the plate was full strength but t welded to the SSHS, together with a superimposed fillet weld. — The end plate is usually a plate cut to suit. — The bolting category used is normally 8.8/TB (tensioned). — The end plate is assumed to be uniform and continuou s i.e. solid, with the mem ber butted ont o one face of the plate. So-called ‘ring flanges’, where the plate has a hole to accept the member slotted into it, or that have a significant hole aligned with the longitudinal axis of the member, are not covered in this design guidance. Ring flanges are typically very thick, as the plate is designed to remain elastic, whereas solid end plates can be designed for plastic behaviour in structural applications and are usually much thinner. Ring flanges would usually be required for cases where the SSHS member is fluid filled or intended to be concrete filled. The design model in this Guide is not applicable to ring flanges. — It is assumed that the members on each s ide of the con nection end plates are of similar size suc h that there are no through thickness bending or shearing effects caused by lack of direct bearing load paths through the thickness of the end plates. — The design models ado pted are valid for SHS/RHS members only. There are no mod els available for CHS members. The bolted moment end plate may be used in a number of different configurations, some of which are shown in Figure 17. The main focus of this section is on the bolted solid end plate for RHS/SHS members under moment loading as utilised typically in the beam splice connection shown in Figure 17(b).


37


(a) Rafter apex connection

FIGURE 17

(b) Beam splice connection

TYPICAL CONNECTION ASSEMBLIES UTILISING BOLTED MOMENT END PLATES

The bolted moment end plate is designed to resist predominantly moment loading. Where present, axial load is assumed to be sufficiently small such that the combined moment and axial load does not result in a situation where the compression or tension at any point around the connection reverses direction from that present for the moment only case. Where axial loads are significant, the bolted end plate splice design model described in the previous section should be adopted.

Summary of design checks: General

DESIGN CHECK NO. 1 — Detailing requirements DESIGN CHECK NO. 2 — Validity limits and minimum design actions

Bending mom ent and axial tension

DESIGN CHECK NO. 3 — Design capacity of bolts in axial tension DESIGN CHECK NO. 4 — Design capacity of welds to SHS/RHS member DESIGN CHECK NO. 5 — Design capacity of end plate in bending DESIGN CHECK NO. 6 — Design capacity of end plate due to punching shear

Shear

DESIGN CHECK NO. 7 — Design capacity of bolts in shear and ply bearing DESIGN CHECK NO. 8 — Design capacity due to tear out in end plate DESIGN CHECK NO. 9 — Design capacity of welds to SHS/RHS member

38




Table

End plate type

Member type

End plate grade (MPa)

4.13.1(a)

rectangular 2 sided

SHS Grade 350

250

moment

50%

4.13.1(b)

rectangular 2 sided

SHS Grade 350

250

moment

maximum

4.13.2(a)

rectangular 2 sided

RHS Grade 350

250

moment

50%

4.13.2(b)

rectangular 2 sided

RHS Grade 350

250

moment

maximum

4.13.3(a)

rectangular 2 sided

SHS Grade 450 (refer Note 12)

350

moment

50%

4.13.3(b)

rectangular 2 sided


350

moment

maximum

4.13.4(a)

rectangular 2 sided

RHS Grade 450 (refer Note 12)

350

moment

50%

4.13.4(b)

rectangular 2 sided


350

moment

maximum

4.13.5(a)

rectangular 4 sided

SHS Grade 350

250

moment

50%

4.13.5(b)

rectangular 4 sided

SHS Grade 350

250

moment

maximum

4.13.6(a)

rectangular 4 sided

RHS Grade 350

250

moment

50%

4.13.6(b)

rectangular 4 sided

RHS Grade 350

250

moment

maximum

4.13.7(a)

rectangular 4 sided


350

moment

50%

4.13.7(b)

rectangular 4 sided


350

moment

maximum

4.13.8(a)

rectangular 4 sided


350

moment

50%

4.13.8(b)

rectangular 4 sided


350

moment

maximum


Design action

Capacity (refer Not e 1)

39

9.13


Mit red kn ee (TDG 25)

FIGURE 18

TYPICAL FULLY WELDED MITRED KNEE CONNECTION CONFIGURATIONS

The mitred knee connection comprises two approximately similarly sized SSHS members meeting at an angle of 90 degrees or greater. Each member is profile cut to the mitre angle and either welded directly to each other or via an intermediate stiffening plate. Typical examples are shown in Figure 18 for both SHS/RHS and CHS members. Features of the connection are: — Welds are typically a combination of fillet welds and full str ength butt welds, as shown in Figure 3.2. — The stiffener p late, where specified, is either a standar d size flat bar or a p late cut to suit. The main focus of this model is the fully welded mitred knee connection in both stiffened and unstiffened versions.


40


Combined actions DESIGN CHECK NO. 3 — Design capacity for combined moment and axial load DESIGN CHECK NO. 4 — Design capacity for shear . k r o w t e n r u o y m o r f d e t e l e d e . b d t e s t u i b i m h n o r o i p t a e c r i l a b n u o p i t s u i h b i t r , t I s i S d A d e n h t a e m g o r a r f o n t g s i , s e e r s u y k n r a o p w t m o e c n r ; y u p o o y c d r l u e o p h a p S . e d n e o t t i s u l m r p e y p l s n i o r k r e t o u w t p e m n o r c u r o u y o n y o o t n o g i n t i u v b a i r s t s s i d w o r l o l a e e g c a r n o e t c s i l , e r s e u s u : l I S a A n o e s h r e t f p o r s u r o e y : b I m S e A m e e h t t f a r o o s p r r e o b c l m a e i c m n l a a n u i d F i . i v t h d g i n i r l y a p i o c c n I a n S i A F

DESIGN CHECK NO. 5 — Design capacity of welds to SSHS members As well as a worked example, the following Des ign Capacity Tables are provided with this des ign model, derived using the Design Checks stated above:

9.14

Table

Member type

Grade (MPa)

Connection type

Design action

3.13.1

CHS

250

unstiffened

moment with axial load

3.13.2

CHS

350

unstiffened


3.13.3

SHS

350

unstiffened


3.13.4

SHS

450

unstiffened


3.13.5

RHS

350

unstiffened


3.13.6

RHS

450

unstiffened


T, Y and X con nectio ns (TDG 25)

FIGURE 19

TYPICAL T, Y AND X CONNECTION CONFIGURATIONS

Typical T and Y connections comprise a brace member profile cut and fully welded all round to the chord member. All members are SSHS members.


41

Features of the connection are: — Welds are usu ally fil let welds con tinuous all round the brace to chord connection. Butt welds may be necessary in some locations due to the local plate alignments. . k r o w t e n r u o y m o r f d e t e l e d e . b d t e s t u i b i m h n o r o i p t a e c r i l a b n u o p i t s u i h b i t r , t I s i S d A d e n h t a e m g o r a r f o n t g s i , s e e r s u y k n r a o p w t m o e c n r ; y u p o o y c d r l u e o p h a p S . e d n e o t t i s u l m r p e y p l s n i o r k r e t o u w t p e m n o r c u r o u y o n y o o t n o g i n t i u v b a i r s t s s i d w o r l o l a e e g c a r n o e t c s i l , e r s e u s u : l I S a A n o e s h r e t f p o r s u r o e y : b I m S e A m e e h t t f a r o o s p r r e o b c l m a e i c m n l a a n u i d F i . i v t h d g i n i r l y a p i o c c n I a n S i A F

— The end of the brace memb er is profil e cut to ensure a good fit with minimum gap bet ween the brace member end and the face of the chord member at all points around the perimeter of the brace member connection area. — A T connection i s a particular variant of the Y connect ion with the brace member at right angles to the chord member. — An X c onnection has a s econd brace member connected to the opposite face of the chord. Design models for X connections generally have the two brace members collinear. The main focus of this model is the T or Y connection subjected to pure axial load in all members or to moment in the brace member. Interaction between axial load and moment is also presented. X connections are treated as a variation of T and Y connections.

Summary of design checks: General DESIGN CHECK NO. 1


DESIGN CHECK NO. 2


Axial tensio n or compression in brac e member DESIGN CHECK NO. 3

— Design capacity due to chord face plastification

DESIGN CHECK NO. 4

— Design capacity due to chord side wall failure

DESIGN CHECK NO. 5

— Design capacity due to chord punching shear

DESIGN CHECK NO. 6

— Design capacity due to local yielding of brace member

DESIGN CHECK NO. 7


DESIGN CHECK NO. 8

— Design capacity due to chord shear

Bending moment in brace member DESIGN CHECK NO. 9

— Design capacity due to chord face plastification

DESIGN CHECK NO. 10 — Design capacity due to chord side wall failure DESIGN CHECK NO. 11 — Design capacity due to chord punching shear DESIGN CHECK NO. 12 — Design capacity due to local yielding of brace member DESIGN CHECK NO. 13 — Design capacity of welds to SSHS member

Combined axial load and bending moment in brace member DESIGN CHECK NO. 14 — Combined axial load and moment interaction

42




9.15

Table

Member type

Grade (MPa)

Connection type

Design action

4.13.1

CHS

250

T connection

tension / compression

4.13.2

CHS

350

T connection


4.13.3

SHS

350

T connection


4.13.4

SHS

450

T connection


K & N gap con necti ons (TDG 26)

(a) K & N gap connections

(b) KT gap connections

FIGURE 20

TYPICAL K & N AND KT GAP CONNECTION CONFIGURATIONS

K & N gap connections comprise two brace members profile cut and fully welded all around to the chord member, as shown in Figure 20(a). All members are SSHS members.


43

Features of the connection include: — Welds are usually fillet welds continuous all aro und the brace to chord connec tion. However, due to variation in the relative angle between connected elements, in some locations butt welds are necessary. . k r o w t e n r u o y m o r f d e t e l e d e . b d t e s t u i b i m h n o r o i p t a e c r i l a b n u o p i t s u i h b i t r , t I s i S d A d e n h t a e m g o r a r f o n t g s i , s e e r s u y k n r a o p w t m o e c n r ; y u p o o y c d r l u e o p h a p S . e d n e o t t i s u l m r p e y p l s n i o r k r e t o u w t p e m n o r c u r o u y o n y o o t n o g i n t i u v b a i r s t s s i d w o r l o l a e e g c a r n o e t c s i l , e r s e u s u : l I S a A n o e s h r e t f p o r s u r o e y : b I m S e A m e e h t t f a r o o s p r r e o b c l m a e i c m n l a a n u i d F i . i v t h d g i n i r l y a p i o c c n I a n S i A F

— The ends of the brace members are profile cut to ensure a g ood fit with m inim um gap between t he brace member end and the face of the chord member at all points around the perimeter of the brace member connection area. — There is a defined space or ‘gap’ between the bra ce members where they land on the connected face of the chord member. — An N c onnection is a part icular type of K conn ection where one brace member is at right angles to the chord member. The main focus of this section is the K or N gap connection subjected to pure axial load in all members, as would be expected where the connection is part of a truss assembly. Any moments that occur in the connection members are secondary, usually produced as a result of noding eccentricity. KT connections, which are shown in Figure 20(b), are a combination of a K and T connection. The design of KT connections is detailed, with design guidance related back to the K or T connection, as appropriate.


Axial tensio n or compression DESIGN CHECK NO. 3 — Design capacity due to chord face plastification DESIGN CHECK NO. 4 — Design capacity due to chord punching shear DESIGN CHECK NO. 5 — Design capacity due to local yielding of brace member DESIGN CHECK NO. 6 — Design capacity of welds to SSHS brace members DESIGN CHECK NO. 7 — Design capacity due to chord shear As well as a worked example, the following Des ign Capacity Tables are provided with this des ign model, derived using the Design Checks stated above:

44

Table

Member type

Grade (MPa)

Connection type

Design action

3.13.1

CHS

250

K connection


3.13.2

CHS

350

K connection


3.13.3

SHS

350

K connection


3.13.4

SHS

450

K connection



9.16


K & N overl ap con nectio ns (TDG 27)

(a) K & N overlap connections

(b) KT overlap connections

FIGURE 21

TYPICAL K & N OVERLAP CONNECTION CONFIGURATIONS

K & N overlap connections comprise two (usually) brace members profile cut and fully welded all around to the chord member, as illustrated in Fig. 21. One brace member fully or partially contacts the other brace member. All members are SSHS members. Features of the connection include: — Welds are usually fillet weld s cont inuous all around the brace t o chord connection. — The end of the brace members are profile cut to ensure a good fit with minimum gap between the brace member end and the face of the chord member (and adjacent brace member) at all points around the perimeter of the brace member connection area. — There is a defined o verlap bet ween each b rac e member so tha t at least one brace member is fully or partially welded to the other brace member as well as to the chord member.


45

— An N c onnection is a part icular type of K c onnection where one brace member is at rig ht angles to the chord member.


— The con nection may be noded , where the centrelines of all members coincide at a point, or there may be a defined node eccentricity. Node eccentricity is often introduced to spread or contract the web member spacing to facilitate easier or simpler connection fabrication. The main focus of this model is the K or N overlap connection subjected to pure axial load in all members. Any moments that occ ur in the connection members are secondary, usually pro duc ed as a res ult of the noding eccentricity. KT connections, which are a combination of a K and T connection as illustrated in Fig. 21(b), are detailed, with design guidance provided related back to the K and T connections.


Axial tensio n or compression DESIGN CHECK NO. 3 — Design capacity due to local yielding of overlapping brace DESIGN CHECK NO. 4 — Design capacity due to local yielding of chord member DESIGN CHECK NO. 5 — Design capacity due to brace shear DESIGN CHECK NO. 6 — Design capacity of welds to brace members The development of a meaningful set of design capacity tables for K & N overlap connections involves consideration and rationalisation of three separate members which, by virtue of the overlap present, interact with each other, resulting in significant permutations of behaviour. For these reasons, design capacity tables have not been produced for this connection type.

10

CONCLUSION

The use of structural steel hollow sections (SSHS) is increasing in relative terms, recognising the inherent member efficiencies possible and the aesthetics able to be realised, in particular for architecturally exposed structural steel (AESS) solutions. Connection design and sympathetic detailing play a significant part in ensuring SSHS structures meet the client performance expectations, in terms of both cost and aesthetics. The object of the Tubular Connection Series is to provide a rationalised approach to the design, detailing and fabrication of the commonly adopted SSHS connections. The benefits of this approach include: •

•

•

•

•

46

Provision to the competent professional person as designer, a range of reliable and economic connections accompanied by design capacity tables (wherever possible) for each connection type Elimination of the need for repetitive computation by structural engineers as much as practicable Scope for the fabricator to produce connection components by production engineering methods where possible. It is noted however that a number of the connection types have limited components. Advantages that can be expected to flow from industry rationalisatio n, such as better communication, better availability of materials and suitable components Provide a considerable impetus towards improving the economy and therefore the competitive position of structural steel in the Australian building industry



11

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Wardenier, J., Kurobane, Y., Packer, J.A., van der Vegte, G.J. and Zhao, X.-L., Design ‘ guide for circular hollow section (CHS) joints under predominantly static loading ’, (Construction with hollow nd sections; 1), 2 edition, Comité International pour le Développement et l’Etude de la Construction Tubulaire, 2008.

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Packer, J.A., Wardenier, J., Zhao, X.-L., van der Vegte, G.J. and Kurobane, Y. D ‘ esign guide for rectangular hollow section (RHS) joints under predominantly static loading ’, (Construction with hollow nd sections; 3), 2 edition, Comité International pour le Développement et l’Etude de la Construction Tubulaire, 2009.

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47


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American Petroleum Institute, API Spec 5L ‘Specification for line pipe ’, 2004.

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12

NOTATION b0 = overall width of SHS/RHS member d 0 = overall depth of SHS/RHS member = diameter of CHS chord member

f u = tensile strength of SSHS member material f y = yield stress of SSHS member material

o  ϕ ϕm  48

= external corner radius of SHS/RHS member = thickness of material = capacity factor, according to AS 4100 = material reduction factor detailed in Tubular Design Guide 20 and based on the yield-to-ultimate limiting factor of 0.8 and the reduction factor of 0.9 for yield stress greater than 350 MPa and up to 460 MPa, both described in CIDECT Design Guides 1 and 3. = slenderness ratio for component subject to axial compression


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Premier Steel www.onesteel.com RJE (Rigby Jones) www.rigbyjones.com.au . k r o w t e n r u o y m o r f d e t e l e d e . b d t e s t u i b i m h n o r o i p t a e c r i l a b n u o p i t s u i b h i t r , t I s i S d A d e n h t a e m g o a r f r o n t g s i , s e e r s u y k n r a o p w t m o e c n r ; y u p o o y c d r l u e o p h a p S . e d n e o t t i s u l m r p e y p l s n i o r k r e t o u w t p e m n o r c u r o u y o n y o o t n o g i n t i u v b a i r t s s s i d w o r l o l a e e g c a r n o e t c s i l , e r s e u s u : l I S a A n o e s h r e t f p o r s u r o e y : b I m S e A m e e h t t f a r o o s p r r e o b c l m a e i c m n l a a n u i d F i . i v t h d g i n i r l y a p i o c c n I a n S i A F

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C & V Engineering Services 23 Church Avenue Mascot NSW 2020

Southern Steel Supplies www.southernsteel.com.au Southern Steel W.A www.southernsteelwa.com.au

Charles Heath Industries 18 Britton Street Smithfield NSW 2164

Statewide Of fice www.statewideof fice.com.au

Combell Steelfab 51 Jedda Road Prestons NSW 2170

Steelpipe Australia www.steelpipe.com.au

Coolamon Steelworks 81 Wade Street Coolamon NSW 2701

Stramit Building Products www.stramit.com.au Surdex Steel www.surdexsteel.com.au Vulcan Steel 03 8792 9600 Vulcan Steel (New Zealand) +64 9 273 7214

ASI STEEL FABRICATOR MEMBERS AUSTRALIAN CAPITAL TERRITORY

D.A.M. Structural Steel 65 Hartley Road Smeaton Grange NSW 2567 D.M.E. Engineering Services 8 Dupas Street Smithfield NSW2164

02 6280 5688

Davebilt Industries 116 Showground Road North Gosford NSW 2250

02 6255 7524

Designed Building Systems 144 Sackville Street Fair field NSW 2165

NEW SOUTH WALES ACA-Ace Construction Australia 22 York Road Ingleburn NSW 2565

02 9618 7874

ACT Steelworks 32 Faunce Street Queanbeyan NSW 2620

02 6297 4611

Adua Engineering Aust. 25 – 27 Loftus Street Riverstone NSW 2765

02 9627 2933

Algon Steel 7 Pippita Close Beresfield NSW 2322

02 4966 8224

Align H Lot 102 Lackey Road Moss Vale NSW 2577

02 4869 1594

Aljen Engineering 17 Deering Street Ulladulla NSW 2539

02 4455 7299

Allthread Industries 15 Bellona Avenue Regents Park NSW 2143

02 9645 1122

50

02 9748 6730

In City Steel 21 Dampier Place Prestons NSW 2170

Belmore Engineering 47 Showground Road Tamworth NSW 2340

Southern Queensland Steel www.sqsteel.com.au

Oz Metalwork 11 Cheney Place Mitchell ACT 2911

02 6362 3100

AWI Steel 36 Day Street North Silverwater NSW 2128

Rondo Building Services www.rondo.com.au

Baxter Engineering 177 Gladstone Street Fyshwick ACT 2609

02 4352 2468

ILB Steel Buildings 24-28 Lords Place Orange NSW 2800

Amarcon Group 18-20 Lucca Road North Wyong NSW 2259

Edcon Steel Unit 3a, 9-13 Winbourne Road Brookvale NSW 2100 Ficogi Engineering 33 Liverpool Street Ingleburn NSW 2565 Flame-Cut 68 Elizabeth Street Wetherill Park NSW 2164 Forgacs Engineering 50 Fitzroy Street Carrington NSW 2294 Halley and Mellowes 10 Hereford Street Berkeley Vale NSW 2261 HF Hand Constructors 26-32 Akubra Place South Kempsey NSW2 440 Hutchins Bros 25-27 Driscoll Road Narrandera NSW 2700


W E Smith Engineering Hamilton Drive Boambee NSW 2450

. k r o w t e n r u o y m o r f d e t e l e d e . b d t e s t u i b i m h n o r o i p t a e c r i l a b n u o p i t s u i b h i t r , t I s i S d A d e n h t a e m g o a r f r o n t g s i , s e e r s u y k n r a o p w t m o e c n r ; y u p o o y c d r l u e o p h a p S . e d n e o t t i s u l m r p e y p l s n i o r k r e t o u w t p e m n o r c u r o u y o n y o o t n o g i n t i u v b a i r t s s s i d w o r l o l a e e g c a r n o e t c s i l , e r s e u s u : l I S a A n o e s h r e t f p o r s u r o e y : b I m S e A m e e h t t f a r o o s p r r e o b c l m a e i c m n l a a n u i d F i . i v t h d g i n i r l y a p i o c c n I a n S i A F

Walpett Engineering 52 Hincksman Street Queanbeyan NSW 2620 Weldcraft Engineering 79 Thuralilly Street Queanbeyan NSW 2620 WGE 151-153 Five Islands Road Cringila NSW 2502

02 6650 8888

Noosa Engineering & Crane Hire 9 Leo Ally Road Noosaville QLD 4566

02 6297 1277

Pierce Engineering 48 Quinn Street North Rockhampton QLD 4701 07 4927 5422

02 6297 1453

Quality Assured Bolt & Steel Fabrication 44 Andrew Campbell Drive Narangba QLD 4504 07 3888 3888

02 4272 2200

SJC Engineering Unit 2 / 11 Natasha Street Capalaba QLD 4157

Alltype Welding 55 Christensen Road Stapylton QLD 4207 Austin Engineering 173 Cobalt Street Carole Park QLD 4300 Austweld Engineering 77 Coleyville Road Mutdapilly QLD 4307 Beenleigh Steel Fabrications 41 Magnesium Drive Crestmead QLD 4132 Bend-Worx 1 Viking Drive Wacol QLD 4076 Brown Steel 157 O’Mara Road Charlton QLD 4350 Cairns Steel Fabricators 6 Walters Street Portsmith QLD 4870 Casa Engineering (Brisbane) 151 Tile Street Wacol QLD 4076 Central Engineering 19 Traders Way Currumbin QLD 4223 Compliant Steel 1294 Kingsthorpe-Haden Road Boodua QLD 4401 Durable Engineering 460 Beaudesert Road Salisbury QLD 4107 DWW Engineering 53 Station Avenue Darra QLD 4076 Gay Constructions 225 Queensport Road Murarrie QLD 4172 Idec Solutions 58 Anton Road Hemmant QLD 4174 KG Fabrication Unit 3/35 Sodium Street Narangba QLD 4504 Morton Steel 78 Freight Street Lytton QLD 4178

07 4633 0244

07 3807 1820

07 3271 2622

07 5467 1122

07 3803 6033

07 3271 1377

07 4614 3901

Haywards Steel Fabrication & Construction 160 Hobart Road Launceston TAS 7249 03 6391 8508 VICTORIA

07 3439 6126

Aus Iron Industries 15-17 Galli Court Dandenong South VIC 3175

03 9799 9922

07 4152 6311

Australian Engineering 176 Colchester Road Bayswater VIC 3153

03 9728 5500

07 3271 2988

Bahcon Steel 549 Princes Drive Morwell VIC 3840

03 5134 2877

07 4775 1266

Brunton Engineering & Construction 54-56 Freight Drive Somerton VIC 3062 03 9303 7475

07 3260 5189

Geelong Fabrications 5-17 Madden Avenue Geelong VIC 3214

03 5275 7255

07 3345 4000

GFC Industries 42 Glenbarry Road Campbellfield VIC 3061

03 9357 9900

07 5484 0109

GVP Fabrications 25-35 Japaddy Street Mordialloc VIC 3195

03 9587 2172

Keppel Prince Engineering 184 Darts Road Portland VIC 3305

03 5523 8888

Kiewa Valley Engineering 34 Moloney Drive Wodonga VIC 3690

02 6056 6271

Sun Engineering 113 Cobalt Street Carole Park QLD 4300 Thomas Steel Fabrication 19 Hartley Street Garbutt QLD 4812 Tobin Projects 2/15 Landy Street Northgate QLD4013

Widgee Engineering 532 Upper Widgee Road Widgee QLD 4570 SOUTHAUSTRALIA

07 4035 1506

Advanced Steel Fabrications 61-63 Kapara Road Gillman SA 5013

07 3271 2300

Ahrens Group Wilhelm Road Kingsford SA 5118

08 8521 0000

07 5534 3155

BGI Building Group 21-23 Tanunda Road Nuriootpa SA 5355

08 8562 2799

07 4696 7665

Bowhill Engineering Lot 100, Weber Road Bowhill SA 5238

07 3277 7007

Gadaleta Steel Fabrication 12 Wattle Street Port Pirie SA 5540

07 3375 5841

Manuele Engineers 240-280 Morphett Road North Plympton SA 5037

07 3890 9500

RC & ML Johnson 671 Magill Road Magill SA 5072

07 3908 9600

SA Structural 9-11 Playford Cresent Salisbury North SA 5108

07 3888 4646

Samaras Structural Engineers 96-106 Grand Trunkway Gillman SA 5013

07 3396 5322

Tali Engineering 119 Bedford Street Gillman SA 5013


TASMANIA

07 3390 2217

Stewart & Sons Steel 11-17 Production Street Bundaberg QLD 4670

W D T Engineers 124 Ingram Road Acacia Ridge QLD 4110

08 8287 6489

Apex Welding & Steel Fabrication 15 Centofanti Place Thomastown VIC 3074 03 9466 4125

Steel Fabrications Australia Unit 12, 63 Burnside Road Stapylton QLD 4207

QUEENSLAND AG Rigging & Steel 207-217 McDougall Street Toowoomba QLD 4350

07 5449 7477

Williams Metal Fabrication 181 Philip Highway Elizabeth South SA 5112

08 8447 7100

08 8570 4208

08 8633 0996

08 8414 2000

08 8333 0188

08 8285 5111

08 8447 7088

Materials Fabrication/ Melbourne Facades 5/23 Bell Street Preston VIC 3072 03 9480 0054 Metalform Structures 2 Zilla Court Dandenong VIC 3175

03 9792 4666

Minos Structural Engineering Building 3, 69 Dalton Road Thomastown VIC 3074

03 9465 8665

Multicoat 7 Laser Drive Rowville VIC 3178

03 9764 8188

Page Steel Fabrications 20 Fulton Drive Derrimut VIC 3030

03 9931 1600

P&T Weldings Vic 11 Davies Avenue North Sunshine VIC 3020

03 9367 5957

Riband Steel (Wangaratta) 69-81 Garden Road Clayton VIC 3168

03 9547 9144

SGA Engineering (Aust) 1/67 High Street Melton VIC 3337

03 9747 9600

08 8240 4711

51

Skrobar Engineering 34 Elliott Road Dandenong South VIC 3175

. k r o w t e n r u o y m o r f d e t e l e d e . b d t e s t u i b i m h n o r o i p t a e c r i l a b n u o p i t s u i b h i t r , t I s i S d A d e n h t a e m g o a r f r o n t g s i , s e e r s u y k n r a o p w t m o e c n r ; y u p o o y c d r l u e o p h a p S . e d n e o t t i s u l m r p e y p l s n i o r k r e t o u w t p e m n o r c u r o u y o n y o o t n o g i n t i u v b a i r t s s s i d w o r l o l a e e g c a r n o e t c s i l , e r s e u s u : l I S a A n o e s h r e t f p o r s u r o e y : b I m S e A m e e h t t f a r o o s p r r e o b c l m a e i c m n l a a n u i d F i . i v t h d g i n i r l y a p i o c c n I a n S i A F

Stilcon Holdings 37 Link Court Brooklyn VIC 3012 Structural Challenge 63 Star Crescent Hallam VIC 3803 Thornton Engineering Australia 370 Bacchus Marsh Road Corio VIC 3214 Uptime Services Management 35-37 Hume Court Reserve Bell Park VIC 3215 Wolter Steel Co. 12 Elite Way Carrum Downs VIC 3201

03 9792 0655

Cays Engineering 17 Thornborough Road Greenfields WA 6210

08 9582 6611

Italsteel W.A. 1 Forge Street Welshpool WA 6106

03 9314 1611

Civmec Construction and Engineering 16 Nautical Drive Henderson WA 6166 08 9437 6288 S

JV Engineering 100 Dowd Street Welshpool WA 6106

08 6350 6400

03 8795 7111

Complete Steel Projects 31 Cooper Road Jandakot WA 6164

08 9414 8579

MetalworkWA 57 Attwell Street Landsdale WA 6065

08 9303 9996

03 5274 3180

Dwyer Engineering and Construction 16-22 Spencer Street Harvey WA 6220 08 9729 2922

Metro Lintels 2 Kalmia Road Bibra Lake WA 6163

08 9434 1160

EMICOL First Floor, Ascot Place 226 Great Eastern Highway Belmont WA 6104

Mintrex Level 3, 516 Hay Street Subiaco WA 6008

08 9442 3333

08 9374 1142

Fitti Steel Fabrication 11 Erceg Road Yangebup WA 6965

National Lintels 11a Delawney Street Balcatta WA 6021

08 9240 1666

08 9434 1675

Pacific Industrial Company 42 Hope Valley Road Naval Base WA 6165

08 9410 2566

Park Engineers 388 Welshpool Road Welshpool WA 6106

08 9451 7255

R&R Engineering (WA) 1021 Abernethy Road Forestfield WA 6058

08 9454 6522

Scenna Constructions 43 Spencer Street Jandakot WA 6164

08 9417 4447

TLF Constructions Lot 108 Safari Place Carabooda WA 6033

08 9561 8039

Uniweld Structural Co 10 Malcolm Road Maddington WA 6109

08 9493 4411

03 5277 2580

03 9775 1983

WESTERNAUSTRALIA Allstruct Engineering 16 Ryelane Street Maddington WA 6109 Alltype Engineering 52 Hope Valley Road Naval Base WA 6165 Arch Engineering 9 Rivers Street Bibra Lake WA 6163 Austline Fabrications 181 Welshpool Road Welshpool WA 6106 Southern Steelworks 16-18 Hampton Street Mandurah WA 6210 Bossong Engineering 189 Planet Street Welshpool WA 6106

52

08 9459 3823

08 9410 5333

08 9418 5088

08 9451 7300

08 9581 6872

Fremantle Steel Fabrication Co. Lot 600 Prinsep Road Jandakot WA 6164

08 9417 9111

GF Engineering 39 Lionel Street Naval Base WA 6165

08 9410 1615

Global Energy Group Fabrication 54-60 Burlington Street Naval Base WA 6165

08 9437 2111

Highline 8 Colin Jamieson Drive Welshpool WA 6106

08 6454 4000

Inter-Steel 9 Ilda Road Canning Vale WA 6155

08 9256 3311

08 6254 9800

08 9212 2345


. k r o w t e n r u o y m o r f d e t e l e d e . b d t e s t u i b i m h n o r o i p t a e c r i l a b n u o p i t s u i b h t i r , t I s i S d A d e n h t a e m g o a r f r o n t g s i , s e e r s u y k n r a o p w t m o e c n r ; y u p o o y c d r l u e o p h a p S . e d n e o t t i s u l m r p e y p l s n i o r k r e o t u w t p e m n o r c u r o u y o n y o o t n o g i n t i u v b a i r t s s i s d w o r l o l a e g e a c r n o e t c s i l , e r s e u s u : l I S a A n o e s r h t e f p o r s u r o e y : b I m S e A m e e h t t f a r o o s p r r e o b c l m a e i c m n l a a n u i F d . i v t i h d g n i i r l y a p i o c c n I a n S i A F

INTERACTING WITH THE EMBEDDED 3D IMAGES

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next to the figure label.

The first time a 3D-enabled image is clicked on in a PDF viewing session, the Reader 3D engine will take a few seconds to load. Ac cess to subsequent 3D-enabled images in the current vi ewing session will be almost instantaneous. Once a 3D-enabled image is clicked on, the window will open into a 3D immersive interactive world in which the 3D model can be rotated, zoomed, queried and have various rendering styles applied. Depending on what the author has implemented, scripted animations may also be available. The 3D interface and toolbar are shown in the image below. Most tools are self-explanatory and the easiest way to learn is to try! It is important to note that whatever view or configuration you leave the image in, when the document is re-opened in Reader, the view and configuration reverts back to the default set for the image (also accessible by the Default View button).


SCJ v46n2 Web Secured

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