Hollow Sections in Structural Applications (2nd ed.)

240 Pages·2013·26.69 MB·English

J. Wardenier, J.A. Packer, X.-L. Zhao and G.J. van der Vegte
HOLLOW SECTIONS IN
STRUCTURAL APPLICATIONS
ISBN 978-90-72830-86-9

© CIDECT, Geneva, Switzerland, 2010

The publisher and authors have made careful efforts to ensure the reliability of the data contained in this
publication, but they assume no liability with respect to the use for any application of the material and
information contained in this publication.

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ii
PREFACE

The global construction market requires a world-wide coordination of product-, testing-, design- and execution-
standards, so that contracts for delivery of products and for engineering- and construction services can be
agreed on a common basis without barriers.

The mission of CIDECT is to combine the research resources of major hollow section manufacturers in order to
create a major force in the research and application of hollow steel sections world wide. This forms the basis of
establishing coordinated and consistent international standards.

For the ease of use of such standards, it is however necessary to reduce their content to generic rules and to
leave more object-oriented detailed rules to accompanying non-conflicting complementary information, that
have the advantage to be more flexible for the adaptation to recent research results and to be useable together
with any international code.

The book by J. Wardenier, J.A. Packer, X.-L. Zhao and G.J. van der Vegte "Hollow sections in structural
applications" is such a source, developed in an international consensus of knowledge on the topic. It
incorporates the recently revised design recommendations for hollow sections joints of the International
Institute of Welding, IIW (2009) and CIDECT (2008 and 2009). Both are consistent with each other and are the
basis for the Draft ISO standard for Hollow Section Joints (ISO 14346) and may form the basis for future
maintenance, further harmonisation and further development of Eurocode 3 (EN 1993-1-8), AISC (ANSI/AISC
360) and the CISC recommendations.

For the use together with EN 1993-1-8 and ANSI/AISC 360, both being based on the previous IIW (1989)
recommendations, the main differences to these rules are highlighted.

The authors are all internationally recognized experts in the field of tubular steel structures, three of them
having been chairmen of the IIW-Subcommission XV-E on "Tubular Structures" since 1981. This committee is
the pre-eminent international authority producing design recommendations and standards for onshore tubular
structures.

This book should therefore be an invaluable resource for lecturers, graduate students in structural, architectural
and civil engineering, explaining the important principles in the behaviour of tubular steel structures. It is also
addressed to designers of steel structures who can find in it the special items related to the use of hollow
sections, in particular joints, their failure modes and analytical models as supplements to more general design
codes.

Aachen, Germany, August 2010

Prof. Dr.-Ing. Dr.h.c. Gerhard Sedlacek
iii
ACKNOWLEDGEMENTS

This book gives the background to design with structural hollow sections in general and in particular for joints to
hollow sections. For the latter, the recently updated recommendations of the International Institute of Welding
(IIW, 2009) and CIDECT (2008 and 2009) are adopted.

The background to design recommendations with the relevant analytical models is especially important for
students in Structural and Civil Engineering, whereas the design recommendations themselves serve more as
an example. Since the available hours for teaching Steel Structures, and particularly Tubular Structures, vary
from country to country, this book has been written in a modular form. The presentation generally follows
European codes, but the material is readily adapted to other (national) codes.

Since the first edition of this book was used not only by students but also by many designers, this second
edition was needed due to the recent update of the recommendations by IIW and the subsequent revision of
the CIDECT Design Guides Nos. 1 and 3 in 2008 and 2009.

The new IIW (2009) recommendations and the revised CIDECT Design Guides Nos. 1 and 3 (2008 and 2009)
are consistent with each other and are the basis for the Draft ISO standard for Hollow Section Joints (ISO
14346). Although the current Eurocode 3 (EN 1993-1-8, 2005) and AISC (2010) recommendations are still
based on the previous IIW (1989) and CIDECT (1991 and 1992) recommendations, it is expected that in the
next revision these will follow the new IIW and CIDECT recommendations presented in this book.

Besides the static design recommendations and background for hollow section joints, information is given for
member design in Chapter 2, composite structures in Chapter 4, and fire resistance in Chapter 5. These
chapters fully comply with the latest versions of the Eurocodes (EN 1993 and EN 1994). Further, fatigue design
of hollow section joints is covered in Chapter 14.

We wish to thank our colleagues from the IIW Sub-commission XV-E "Tubular Structures" and from the
CIDECT Project Working Group and the CIDECT Technical Commission for their constructive comments during
the preparation of this book.

We are very grateful that Prof. J. Stark and Mr. L. Twilt were willing to check Chapters 4 and 5 respectively on
composite members and fire resistance.

Appreciation is further extended to the authors of CIDECT Design Guides Nos. 1 to 9 and to CIDECT for
making parts of these Design Guides or background information available for this book.

Finally, we wish to thank CIDECT for the initiative to update this book.

Delft, The Netherlands, September 2010

Jaap Wardenier
Jeffrey A. Packer
Xiao-Ling Zhao
Addie van der Vegte

iv
CONTENTS

1. Introduction 1
1.1 History and developments 1
1.2 Designation 2
1.3 Manufacturing of hollow sections 2

2. Properties of hollow sections 9
2.1 Mechanical properties 9
2.2 Structural hollow section dimensions and dimensional tolerances 10
2.3 Geometric properties 11
2.4 Drag coefficients 14
2.5 Corrosion protection 14
2.6 Use of internal void 15
2.7 Aesthetics 15

3. Applications 29
3.1 Buildings and halls 29
3.2 Bridges 29
3.3 Barriers 29
3.4 Offshore structures 30
3.5 Towers and masts 30
3.6 Special applications 30

4. Composite structures 37
4.1 Introduction 37
4.2 Design methods 37
4.3 Axially loaded columns 37
4.4 Resistance of a section to bending 39
4.5 Resistance of a section to bending and compression 39
4.6 Influence of shear forces 39
4.7 Resistance of a member to bending and compression 39
4.8 Load introduction 41
4.9 Special composite members with hollow sections 41

5. Fire resistance of hollow section columns 49
5.1 Introduction 49
5.2 Fire resistance 50
5.3 Unfilled hollow section columns 52
5.4 Concrete filled hollow section columns 53
5.5 Water filled hollow section columns 55
5.6 Joints 56

6. Design of hollow section trusses 65
6.1 Truss configurations 65
6.2 Joint configurations 65
6.3 Limit states and limitations on materials 66
6.4 General design considerations 67
6.5 Truss analysis 68

7. Behaviour of joints 75
7.1 General introduction 75
7.2 General failure criteria 77
7.3 General failure modes 77
v
7.4 Joint parameters 77

8. Welded joints between circular hollow sections 81
8.1 Introduction 81
8.2 Modes of failure 81
8.3 Analytical models 81
8.4 Experimental and numerical verification 83
8.5 Basic joint strength formulae 83
8.6 Evaluation to design rules 84
8.7 Other types of joints 85
8.8 Design charts 86
8.9 Relation to the previous recommendations of IIW (1989) and CIDECT (1991) 87
8.10 Concluding remarks 87

9. Welded joints between rectangular hollow sections 103
9.1 Introduction 103
9.2 Modes of failure 103
9.3 Analytical models 104
9.4 Experimental and numerical verification 106
9.5 Basic joint strength formulae 106
9.6 Evaluation to design rules 107
9.7 Other types of joints or other load conditions 107
9.8 Design charts 109
9.9 Concluding remarks 109

10. Welded joints between hollow sections and open sections 129
10.1 Introduction 129
10.2 Modes of failure 129
10.3 Analytical models 129
10.4 Experimental verification 131
10.5 Evaluation to design rules 131
10.6 Joints predominantly loaded by bending moments 131

11. Welded overlap joints 141
11.1 Introduction 141
11.2 Modes of failure 141
11.3 Analytical models for RHS overlap joints 141
11.4 Analytical models for CHS overlap joints 143
11.5 Analytical models for overlap joints with an open section chord 143
11.6 Experimental and numerical verification 143
11.7 Joint strength formulae 144

12. Welded I beam-to-CHS or RHS column moment joints 151
12.1 Introduction 151
12.2 Modes of failure 151
12.3 Analytical models 151
12.4 Experimental and numerical verification 153
12.5 Basic joint strength formulae 153
12.6 Concluding remarks 154

13. Bolted joints 161
13.1 Flange plate joints 161
13.2 End joints 161
13.3 Gusset plate joints 162
13.4 Splice joints 162
vi
13.5 Beam-to-column joints 162
13.6 Bracket joints 163
13.7 Bolted subassemblies 163
13.8 Purlin joints 163
13.9 Blind bolting systems 163
13.10 Nailed joints 163

14. Fatigue behaviour of hollow section joints 175
14.1 Definitions 175
14.2 Influencing factors 175
14.3 Loading effects 176
14.4 Fatigue strength 177
14.5 Partial factors 177
14.6 Fatigue capacity of welded joints 177
14.7 Fatigue capacity of bolted joints 179
14.8 Fatigue design 180

15. Design examples 193
15.1 Uniplanar truss of circular hollow sections 193
15.2 Uniplanar truss of square hollow sections 197
15.3 Multiplanar truss (triangular girder) 197
15.4 Multiplanar truss of square hollow sections 199
15.5 Joint check using the joint resistance formulae 199
15.6 Concrete filled column with reinforcement 200

16. References 209

Symbols 221

CIDECT 229

vii
viii
1. INTRODUCTION together too voluminous for educational purposes and

do not give the theoretical background, it was decided

to write this book especially to provide background
Design is an interactive process between the
information for students and practitioners in Structural
functional and architectural requirements and the
and Civil Engineering.
strength and fabrication aspects. In a good design, all

these aspects have to be considered in a balanced
This book is written in a limit states design format
way. Due to the special features of hollow sections
(also known as LRFD or Load and Resistance Factor
and their joints, it is here even of more importance
Design in the USA). This means that the effect of the
than for steel structures of open sections. The
factored loads (the specified or unfactored loads
designer should therefore be aware of the various
multiplied by the appropriate load factors) should not
aspects of hollow sections.
exceed the factored resistance of the joint or member.

The factored resistance expressions, in general,
Many examples in nature show the excellent
already include appropriate material and joint partial
properties of the tubular shape with regard to loading
safety factors (γ ) or joint resistance (or capacity)
in compression, torsion and bending in all directions, M
factors (). This has been done to avoid interpretation
see Figs. 1.1 and 1.2. These excellent properties are
errors, since some international structural steelwork
combined with an attractive shape for architectural
specifications use γ values  1,0 as dividers (e.g.
applications (Figs. 1.3 and 1.4). Furthermore, the M
closed shape without sharp corners reduces the area Eurocodes), whereas others use  values  1,0 as
to be protected and extends the corrosion protection multipliers (e.g. in North America and Australia). In
life (Fig. 1.5). general, the value of 1/γM is almost equal to .

Another aspect which is especially favourable for
1.1 HISTORY AND DEVELOPMENTS
circular hollow sections is the lower drag coefficients if
exposed to wind or water forces. The internal void can
be used in various ways, e.g. to increase the bearing The excellent properties of the tubular shape have
resistance by filling with concrete or to provide fire been recognised for a long time; i.e. from ancient time,
protection. In addition, heating or ventilation systems nice examples are known. An outstanding example of
sometimes make use of the hollow section columns. bridge design is the Firth of Forth Bridge in Scotland
(1890) with a free span of 521 m, shown in Fig. 1.6.
Although the manufacturing costs of hollow sections This bridge has been built up from tubular members
are higher than those for other sections, leading to made of rolled plates which have been riveted
higher unit material cost, economical applications are together, because at that time, other fabrication
achieved in many fields. The application field covers methods were not available for these sizes.
all areas, e.g. architectural, civil, offshore, mechanical,
chemical, aeronautical, transport, agriculture and In the same century, the first production methods for
other special fields. Although this book will be mainly seamless and welded circular hollow sections were
focused on the background to design and application, developed. In 1886, the Mannesmann brothers
in a good design not only does the strength have to be developed the skew roll piercing process
considered, but also many other aspects, such as (Schrägwalzverfahren), shown in Fig. 1.7, which made
material selection, fabrication including welding and it possible to roll short thick walled tubulars. This
inspection, protection, erection, in service inspection process, in combination with the pilger process
and maintenance. (Pilgerschrittverfahren, Fig. 1.8), developed some
years later, made it possible to manufacture longer
One of the constraints initially hampering the thinner walled seamless hollow sections.
application of hollow sections was the design of the
joints. However, nowadays design recommendations In the first part of the previous century, an Englishman,
exist for all basic types of joints, and further research Whitehouse, developed the fire welding of circular
evidence is available for many special types of joints. hollow sections. However, the production of welded
circular hollow sections became more important after
Based on the research programmes carried out, the development of the continuous welding process in
CIDECT (Comité International pour le Développement 1930 by the American, Fretz Moon (Fig. 1.9).
et l'Etude de la Construction Tubulaire) has published Especially after the Second World War, welding
Design Guides Nos. 1 to 9 for use by designers in processes have been perfected, which made it
practice. Since these nine Design Guides are all possible for hollow sections to be easily welded
1
together. 1.2 DESIGNATION

The end cutting required for fitting two circular hollow The preferred designations for structural applications
sections together was considerably simplified by the are:
development of a special end preparation machine by - Circular hollow sections (CHS)
Müller (Fig. 1.10). - Rectangular hollow sections (RHS)
- Square hollow sections (SHS)
For manufacturers who did not have such end cutting
machines, the end preparation of circular hollow In Canada and the USA, it is common to speak about
sections remained a handicap. Hollow Structural Sections (HSS), whereas in Europe
also the term Structural Hollow Sections (SHS) is
A way of avoiding the connection problems was the used.
use of prefabricated connectors, e.g. in 1937
Mengeringhausen developed the Mero system. This
system enabled the fabrication of large space 1.3 MANUFACTURING OF HOLLOW
structures in an industrialized way (Fig. 1.11).
SECTIONS

In 1952, the rectangular hollow section was developed
As mentioned, hollow sections can be produced
by Stewarts and Lloyds (now Corus Tubes). This
seamless or welded. Seamless hollow sections are
section, with nearly the same properties as the
made in two phases, i.e. the first phase consists of
circular hollow section, enables the connections to be
piercing an ingot and the second step considers the
made by straight end cuttings.
elongation of this hollow bloom into a finished circular

hollow section. After this process, the tube can go
In the fifties, the problems of manufacturing, end
through a sizing mill to give it the required diameter.
preparation and welding were all solved and from that
More information about other processes, most of them
point of view the way to a successful story was open.
based on the same principle, is given by Dutta (2002).
The remaining problem was the determination of the

strength of unstiffened joints.
Nowadays, welded hollow sections with a longitudinal

weld are mainly made employing either electrical
The first preliminary design recommendations for
resistance welding processes or induction welding
truss connections between circular hollow sections
processes, shown in Fig. 1.12. A strip or plate is
were given by Jamm in 1951. This study was followed
formed by rollers into a cylindrical shape and welded
by several investigations in the USA (Bouwkamp,
longitudinally. The edges are heated, e.g. by electrical
1964; Natarajan & Toprac, 1969; Marshall & Toprac,
resistance, then the rollers push the edges together,
1974), Japan (Togo, 1967; Natarajan & Toprac,
resulting in a pressure weld. The weld protrusion on
1968), and Europe (Wanke, 1966; Brodka, 1968;
the outside of the tube is trimmed immediately after
Wardenier, 1982; Mang & Bucak, 1983; Puthli, 1998;
welding.
Dutta, 2002).

Rectangular hollow sections are made by deforming
Research on joints between rectangular hollow
circular hollow sections through forming rollers, as
sections started in Europe in the sixties, followed by
shown in Fig. 1.13. This forming process can be done
many other experimental and theoretical
hot or cold, using either seamless or longitudinally
investigations. Many of these were sponsored by
welded circular hollow sections. Although it is
CIDECT.
common practice to use longitudinally welded hollow

sections, for the very thick sections, seamless
Besides these investigations on the static behaviour,
sections may be used.
in the last 25 years much research was carried out on

the fatigue behaviour and other aspects, such as
Square or rectangular hollow sections are sometimes
concrete filling of hollow sections, fire resistance,
made by forming a single strip to the required shape
corrosion resistance and behaviour under wind
and closing it by a single weld, preferably in the
loading. middle of a face.

Large circular hollow sections are also made by rolling

plates through a so-called U-O press process shown

in Fig. 1.14. After forming the plates to the required
2