Tubular Design Guide 24:

Bolted planar connections

by

P.W. Key

and

A.A. Syam

first edition – 2014

 AUSTRALIAN STEEL INSTITUTE
(ABN)/ACN (94) 000 973 839

Tubular Design Guide 24:

Bolted planar connections

Copyright © 2014 by AUSTRALIAN STEEL INSTITUTE

Published by: AUSTRALIAN STEEL INSTITUTE

All rights reserved. This book or any part thereof must not be reproduced in any form without the written
permission of Australian Steel Institute.
Note to commercial software developers: Copyright of the information contained within this publication is
held by Australian Steel Institute (ASI). Written permission must be obtained from ASI for the use of any
information contained herein which is subsequently used in any commercially available software package.
FIRST EDITION 2014 (LIMIT STATES)
National Library of Australia Cataloguing-in-Publication entry:
Key, Peter W.
Tubular Design Guide 24: Bolted planar connections / Peter W. Key, Arun A. Syam
ISBN 9781921476334 (pbk.).
Series: Structural steel tubular connection series.
Includes bibliographical references.
Steel, Structural—Standards – Australia.
Structural engineering.
Syam, A. Arun.
Australian Steel Institute.
624.1821021894

Also in this series:

Tubular Design Guide 20: Background and design basis
Tubular Design Guide 21: Bolted bracing connections
Tubular Design Guide 22: Bolted bracing cleats
Tubular Design Guide 23: Plate fitments
Tubular Design Guide 25: Fully welded—Simple planar connections
Tubular Design Guide 26: Fully welded—Gap planar connections
Tubular Design Guide 27: Fully welded—Overlap planar connections

Disclaimer: The information presented by the Australian Steel Institute in this publication has been prepared for
general information only and does not in any way constitute recommendations or professional advice. While every
effort has been made and all reasonable care taken to ensure the accuracy of the information contained in this
publication, this information should not be used or relied upon for any specific application without investigation
and verification as to its accuracy, suitability and applicability by a competent professional person in this regard.
The Australian Steel Institute, its officers and employees and the authors and editors of this publication do not
give any warranties or make any representations in relation to the information provided herein and to the extent
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diligence, professional or legal advice and in this regards the services of a competent professional person
or persons should be sought.

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bolted planar connections, first edition
 CONTENTS
Page Page
Table of Figures v 3.11.3 DESIGN CHECK NO. 3—
List of Tables iv Design capacity of bolts in
Preface vii axial tension 3-21
About the Authors viii 3.11.4 DESIGN CHECK NO. 4—
Acknowledgements ix Design capacity of welds to
SSHS member 3-22
1 CONCEPT OF DESIGN GUIDES 1-1 3.11.5 DESIGN CHECK NO. 5—
1.1 Background 1-1 Design capacity of end plate
1.2 Included connections 1-2 in bending 3-23
3.11.6 DESIGN CHECK NO. 6—
2 TECHNICAL BASIS 2-1 Design capacity due to local
2.1 Technical background 2-1 yielding of SSHS member 3-28
2.1.1 Technical basis 2-1 3.11.7 DESIGN CHECK NO. 7—
2.1.2 Validity limits 2-1 Design capacity of welds to
2.1.3 Design capacity factors 2-4 SSHS member 3-30
2.2 Properties of connection elements 2-5 3.11.8 DESIGN CHECK NO. 8—
2.2.1 General 2-5 Design capacity of bolts in
2.2.2 Component material yield axial tension 3-31
stress 2-5 3.11.9 DESIGN CHECK NO. 9—
2.2.3 SSHS material properties 2-6 Design capacity of welds to
2.2.4 Design yield stress for SSHS member 3-33
Australian produced SSHS 2-7 3.11.10 DESIGN CHECK NO. 10—
2.2.5 Design capacity of welds 2-7 Design capacity of flange
2.2.6 Design capacity of bolts 2-8 plate in bending 3-35
2.3 References for Sections 1 and 2 2-9 3.11.11 DESIGN CHECK NO. 11—
Design capacity due to local
3 BOLTED END PLATE SPLICE 3-1 yielding of SSHS member 3-36
3.1 Description of connection 3-1 3.12 Design example 3-37
3.2 Typical detailing of connection 3-3 3.13 Design capacity tables 3-42
3.3 Detailing considerations 3-4 3.14 References 3-68
3.4 Background information 3-6
3.4.1 Prying action 3-6 4 BOLTED MOMENT END PLATE 4-1
3.4.2 Recent research—Axial 4.1 Description of connection 4-1
tension 3-7 4.2 Typical detailing of connection 4-3
3.4.3 Recent research—Combined 4.3 Detailing considerations 4-4
axial tension and bending 3-9 4.4 Background information 4-6
3.4.4 Relevant international 4.4.1 Research information—
codes and specifications 3-9 Bending 4-6
3.5 Compliance with AS 4100 4.4.2 Research information—
requirements 3-10 Combined bending and axial
3.6 Basis of design model 3-12 tension/compression 4-8
3.7 Calculation of design actions 3-14 4.4.3 Relevant international codes
3.8 Recommended design model— and specifications 4-8
Connection notation 3-15 4.5 Compliance with AS 4100
3.9 Recommended design model— requirements 4-9
Limits of validity 3-17 4.6 Basis of design model 4-10
3.10 Recommended design model— 4.7 Calculation of design actions 4-12
Summary of design checks 3-18 4.8 Recommended design model—
3.11 Recommended design model— Connection notation 4-13
General 3-19 4.9 Recommended design model—
3.11.1 DESIGN CHECK NO. 1— Limits of validity 4-14
Detailing requirements 3-19 4.10 Recommended design model—
3.11.2 DESIGN CHECK NO. 2— Summary of design checks 4-15
Validity limits and minimum 4.11 Recommended design model—
design actions 3-20 General 4-17
4.11.1 DESIGN CHECK NO. 1—
Detailing requirements 4-17
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 Page Page
4.11.2 DESIGN CHECK NO. 2— 4.11.8 DESIGN CHECK NO. 8—
Validity limits and minimum Design capacity due to tear
design actions 4-18 out in end plate 4-33
4.11.3 DESIGN CHECK NO. 3— 4.11.9 DESIGN CHECK NO. 9—
Design capacity of bolts in Design capacity of welds to
axial tension 4-19 SSHS member 4-34
4.11.4 DESIGN CHECK NO. 4— 4.12 Design example 4-35
Design capacity of welds to 4.13 Design capacity tables 4-41
SSHS member 4-23 4.14 References 4-67
4.11.5 DESIGN CHECK NO. 5—
Design capacity of end 5 NOTATION AND ABBREVIATIONS 5-1
plate in bending 4-24
4.11.6 DESIGN CHECK NO. 6— APPENDICES
Design capacity of end A—Limcon design example output 6-1
plate due to punching shear 4-29 B—ASI Design Guide 24
4.11.7 DESIGN CHECK NO. 7— Comment form 7-1
Design capacity of bolts in
shear and ply bearing 4-32

LIST OF FIGURES
Page Page
Figure 1.1 Connections included in this Figure 3.13 Plastic hinge mechanism
Design Guide 1-2 model for 4 sided connection 3-27
Figure 2.1 Definition of element width Figure 3.14 Design example
for RHS flanges 2-3 configuration 3-37
Figure 3.1 Typical bolted end plate Figure 4.1 Typical bolted moment end
splice connection plate connection
configurations 3-1 configurations 4-1
Figure 3.2 Typical connection Figure 4.2 Typical connection
assemblies utilising bolted assemblies utilising bolted
end plates 3-2 moment end plates 4-2
Figure 3.3 Bolting to circular end Figure 4.3 Bolting to two and four sides
plate splice connection 3-3 of rectangular moment end
Figure 3.4 Bolting to two and four plate connection 4-3
sides of rectangular end Figure 4.4 Clearance required for
plate splice connection 3-3 tensioning bolts 4-5
Figure 3.5 Clearance required for Figure 4.5 Weld induced dishing of
tensioning bolts 3-5 the end plates 4-5
Figure 3.6 Weld induced dishing of Figure 4.6 Bolted moment end plate
the flange plates 3-5 configurations researched
Figure 3.7 T-stub model for at The University of Sydney 4-7
assessment of prying force 3-6 Figure 4.7 Design actions at connection 4-12
Figure 3.8 Generic bolted end plate Figure 4.8 Notation for bolted moment
configurations 3-8 end plate design models 4-13
Figure 3.9 Design actions at connection 3-14 Figure 4.9 Punching shear failure
Figure 3.10 Notation for CHS bolted modes (from The University
end plate 3-15 of Sydney Eight Bolt Design
Figure 3.11 Notation for SHS/RHS Model) 4-30
bolted end plate splice 3-16 Figure 4.10 Minimum edge distances
Figure 3.12 Plastic hinge mechanism for bolt holes in end plate 4-33
model for 2 sided connection 3-27 Figure 4.11 Design example
configuration 4-35

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 LIST OF TABLES
Page Page
Table 2.1 Rationalised validity limits for Table 3.13.5 Bolted end plate connection –
bolted planar connections 2-2 2 sided axial tensile capacity (ΦNconn)
Table 2.2 Section slenderness limits to ≈ 50% of section tensile capacity
AS 4100 and Eurocode 3 2-3 (ΦNt) SHS – Grade 450 3-52
Table 2.3 Section slenderness limits to Table 3.13.6 Bolted end plate connection –
Eurocode 3 for design grades (𝑓𝑦 ) 2 sided axial tensile capacity (ΦNconn)
250, 350 and 450 MPa 2-4 ≈ 50% of section tensile capacity
Table 2.4 Minimum plate material properties (ΦNt) RHS – Grade 450 3-54
to AS/NZS 3678 2-5 Table 3.13.7(a) Bolted end plate connection –
Table 2.5 Strength of flat bars to 4 sided axial tensile capacity (ΦNconn)
AS/NZS 3679.1 Grade 300 2-6 ≈ 50% of section tensile capacity
Table 2.6 Minimum SSHS material (ΦNt) SHS – Grade 350 3-56
properties to AS/NZS 1163 2-6 Table 3.13.7(b) Bolted end plate connection –
Table 2.7 Design yield stress for SSHS 4 sided axial tensile capacity (ΦNconn)
related failure modes for SSHS to ≈ 100% of section tensile capacity
AS/NZS 1163 2-7 (ΦNt) SHS – Grade 350 3-57
Table 2.8 Strength limit state design Table 3.13.8(a) Bolted end plate connection –
capacities of equal leg fillet welds 4 sided axial tensile capacity (ΦNconn)
per unit length category sp, φ = 0.8, ≈ 50% of section tensile capacity
kr = 1.0, material thickness ≥3 mm 2-8 (ΦNt) RHS – Grade 350 3-58
Table 2.9 Strength limit state high strength Table 3.13.8(b) Bolted end plate connection –
structural bolts 8.8/S, 8.8/TB, 8.8/TF 4 sided axial tensile capacity (ΦNconn)
bolting categories (fuf = 830 MPa) 2-8 ≈ 100% of section tensile capacity
Table 3.1 Rationalised validity limits for (ΦNt) RHS – Grade 350 3-59
bolted end plate splice connection 3-17 Table 3.13.9(a) Bolted end plate connection –
Table 3.13.1(a) Bolted end plate connection 4 sided axial tensile capacity (ΦNconn)
axial tensile capacity (ΦNconn) = 50% ≈ 50% of section tensile capacity
of section tensile capacity (φNt) (ΦNt) SHS – Grade 450 3-60
CHS – Grade 250 3-44 Table 3.13.9(b) Bolted end plate connection –
Table 3.13.1(b) Bolted end plate connection 4 sided axial tensile capacity (ΦNconn)
axial tensile capacity (ΦNconn) = ≈ 100% of section tensile capacity
100% of section tensile capacity (ΦNt) SHS – Grade 450 3-62
(ΦNt) CHS –Grade 250 3-45 Table 3.13.10(a) Bolted end plate connection –
Table 3.13.2(a) Bolted end plate connection 4 sided axial tensile capacity (ΦNconn)
axial tensile capacity (ΦNconn) = ≈ 50% of section tensile capacity
50% of section tensile capacity (ΦNt) RHS – Grade 450 3-64
(ΦNt) CHS – Grade 350 3-46 Table 3.13.10(b) Bolted end plate connection –
Table 3.13.2(b) Bolted end plate connection 4 sided axial tensile capacity (ΦNconn)
axial tensile capacity (ΦNconn) = ≈ 100% of section tensile capacity
100% of section tensile capacity (ΦNt) RHS – Grade 450 3-66
(ΦNt) CHS – Grade 350 3-48 Table 4.1 Rationalised validity limits for
Table 3.13.3 Bolted end plate connection – bolted moment end plate connection 4-14
2 sided axial tensile capacity (ΦNconn) Table 4.2 Bolt material properties 4-22
≈ 50% of section tensile capacity Table 4.3 Head dimensions of bolts
(ΦNt) SHS – Grade 350 3-50 Property Class 8.8 to AS/NZS 1252 4-31
Table 3.13.4 Bolted end plate connection – Table 4.13.1(a) Bolted moment end plate
2 sided axial tensile capacity (ΦNconn) connection – 2 sided moment capacity
≈ 50% of section tensile capacity (ΦMconn) ≈ 50% of section moment
(ΦNt) RHS – Grade 350 3-51 capacity (ΦMs) SHS – Grade 350 4-43

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bolted planar connections, first edition
 Page Page
Table 4.13.1(b) Bolted moment end plate Table 4.13.5(a) Bolted moment end plate
connection – 2 sided moment connection – 4 sided moment capacity
capacity (ΦMconn) ≈ maximum of (ΦMconn) ≈ 50% of section moment
section moment capacity (ΦMs)fl capacity (ΦMs) SHS – Grade 350 4-55
SHS – Grade 350 4-44 Table 4.13.5(b) Bolted moment end plate
Table 4.13.2(a) Bolted moment end plate connection – 4 sided moment capacity
connection – 2 sided moment capacity (ΦMconn) ≈ maximum of section
(ΦMconn) ≈ 50% of section moment moment capacity (ΦMs) SHS –
capacity (ΦMs) RHS – Grade 350 4-45 Grade 350 4-56
Table 4.13.2(b) Bolted moment end plate Table 4.13.6(a) Bolted moment end plate
connection – 2 sided moment capacity connection – 4 sided moment capacity
(ΦMconn) ≈ maximum of section (ΦMconn) ≈ 50% of section moment
moment capacity (ΦMs)fl RHS – capacity (ΦMs) RHS – Grade 350 4-57
Grade 350 4-46 Table 4.13.6(b) Bolted moment end plate
Table 4.13.3(a) Bolted moment end plate connection – 4 sided moment capacity
connection – 2 sided moment capacity (ΦMconn) ≈ maximum of section
(ΦMconn) ≈ 50% of section moment moment capacity (ΦMs) RHS –
capacity (ΦMs) SHS – Grade 450 4-47 Grade 350 4-58
Table 4.13.3(b) Bolted moment end plate Table 4.13.7(a) Bolted moment end plate
connection – 2 sided moment capacity connection – 4 sided moment capacity
(ΦMconn) ≈ maximum of section (ΦMconn) ≈ 50% of section moment
moment capacity (ΦMs)fl SHS – capacity (ΦMs) SHS – Grade 450 4-59
Grade 450 4-49 Table 4.13.7(b) Bolted moment end plate
Table 4.13.4(a) Bolted moment end plate connection – 4 sided moment capacity
connection – 2 sided moment capacity (ΦMconn) ≈ maximum of section
(ΦMconn) ≈ 50% of section moment moment capacity (ΦMs) SHS –
capacity (ΦMs) RHS – Grade 450 4-51 Grade 450 4-61
Table 4.13.4(b) Bolted moment end plate Table 4.13.8(a) Bolted moment end plate
connection – 2 sided moment capacity connection – 4 sided moment capacity
(ΦMconn) ≈ maximum of section (ΦMconn) ≈ 50% of section moment
moment capacity (ΦMs)fl RHS – capacity (ΦMs) RHS – Grade 450 4-63
Grade 450 4-53 Table 4.13.8(b) Bolted moment end plate
connection – 4 sided moment capacity
(ΦMconn) ≈ maximum of section
moment capacity (ΦMs) RHS –
Grade 450 4-65

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bolted planar connections, first edition
 PREFACE
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’)
st
connections will be known as the Structural Steel Tubular Connections Series: 1 edition, 2013
(‘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’ published by ASI commencing 2007.
Each book in the new Tubular Connection Series is numbered as a continuation from the
existing series and hence this current book is referred to as ‘Tubular Design Guide 24’
(TDG24). The Tubular Connection Series replaces and enhances an AISC publication released
in 1996 and titled ‘Design of structural steel hollow section connections’ (often referred to as
the ‘Blue Book’). With significant international research undertaken in the interim period and
new and refined design models available, together with improvements in the performance of
Australian produced structural steel hollow sections (SSHS), the time was appropriate to revise
and update the Blue Book.
Tubular Design Guide 24 brings together a number of design models for bolted connections
between tubular members that lie in the same plane and provide continuity in design actions
between the two members associated with the connection. The format and intent of the
technical components of TDG24 is to provide sufficient technical basis to allow TDG24 to be a
self-standing document, but at the same time, where substantive background technical basis is
required, the reader may refer back to both Tubular Design Guide 20 (TDG20) and Handbook 1
of the existing Structural Steel Connection Series.
This has been achieved through extensive local and international literature reviews using ASI’s
close association with like organisations and searching the wealth of material contained in the
ASI Library (the largest steel design library in the Southern Hemisphere). This process consolidated
industry best practice, references and research papers. TDG24, in conjunction with TDG20 and
Handbook 1, formulates the design models and procedures for the assessment of bolted planar
connections between SSHS members.
Following on from the existing Structural Steel Connection Series, the new Tubular Connection
Series format, with separate design guides for individual connection types or groupings related
to similar functions, is intended to facilitate addition to, or revision of, connection model theory
using relevant new local or international research. Connection models developed follow a
stylised page format with a numbered DESIGN CHECK procedure to simplify connection
capacity assessment. Combined with a worked example and accompanying design capacity
tables, each connection model provides a self-standing solution for the design engineer.
Engineering Systems has worked closely with the ASI to further develop their existing Limcon
software as the companion program for this new Tubular Connection Series. The latest version
of Limcon (V3.6) fully implements the new connection design models and was employed in
checking the design tables. The Limcon output for one or more of the worked examples is
included in an appendix to each design guide for each connection design type. The program is
an efficient tool covering the full range of structural connections, including those beyond the
scope of the design capacity tables provided in the Tubular Connection Series.
The existing Structural Steel Connection Series included comment/feedback forms. In the
current series, these are replaced by a recently developed web based eForum facility. Every
publication, seminar and talk that ASI sponsors has or will have a corresponding thread on the
ASI eForum. Users are encouraged to log into the eForum and provide feedback on this current
series. The eForum is located off our website at http://steel.org.au/forum/
P.W. Key
A.A. Syam

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