single-angle compression members welded by one leg to gusset plates

340 Pages·1999·9.72 MB·English

SINGLE-ANGLE COMPRESSION MEMBERS
WELDED BY ONE LEG TO GUSSET PLATES
Sherief Sharl Shukry Sakla,
M.A.Sc., P.Eng.
A Dissertation
Submitted to the Faculty of Graduate Studies and Research
through the Department of Civil and Environmental Engineering
in Partial Fulfilment of the Requirements for
the Degree of Doctor of Philosophy at the
University of Windsor
Windsor, Ontario, Canada
1997
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G 1997 Sherief S. S. Sakla
All Rights Reserved
I hereby declare that I am the sole author of this document.
I authorize the University of Windsor to lend this document to other institutions or
individuals for the purpose of scholarly research.
Sherief Sbarl Shukry Sakla
I further authorize the University of Windsor to reproduce the document by
photocopying or by other means, in total or in part, at the request of other
institutions or individuals for the purpose of scholarly research.
Sherief Sharl Shukry Sakla
THE UNIVERSITY OF WINDSOR requires the signatures of all persons using or
photocopying this document.
Please sign below, and give address and date.
Single-angle compression members are simple structural elements that are wr?-
difficult to analyse and design. These members are usually attached to other members by one
leg only. Thus the load is applied eccentrically. To further complicate the problem the
principal axes of the angle do not coincide with the axes of the Frame or truss of which the
angle is a part. .i\lthou@ it is know that the end conditions affect the ultimate load carrying
capacitl-o f these members. procedures have not been developed to do this as ir is difficult to
euluate the end restraint in many pract ical cases.
D itrrrent design practices were presented and evaluated using experimental test
results obtained tiom pre\-ious research. The two generally accepted design procedures. the
simple-column and the beam-column approaches. in seneral. underestimate the load carrying
capacity of single-angle compression members attached by one leg to a gusset plate. There
is a great variation between different design practices in the prediction of the compressiw
resistance of single-angle members. With that great variation it is difficult to determine the
most appropriate design procedure to follon..
The major objective of this research is to obtain a better understanding of the
behaviour and load carrying capacity of single-angle compression members attached by one
leg to a gusset plate. An experimental investigation was carried out and verified through the
use of the fmite element analysis. The effect of the gusset plate width. thickness and the
unconnected length were studied. The effect of the weld length and pattern used in
connecting the angle to the gusset plate was studied as well. It was found that the thickness
and width of the gusset plate significantly affect the load carrying capacity, but the
unconnected length has only a minor effect. The effect of the length of weld and the weld
pattern used in the connection on the ultimate load carrying capacity can be neglected.
It was found that the finite element method can be used, with a reasonable degree of
accuracy, to predict the behaviour and load carrying capacity of these members. The finite
element method was used to study some 1800 different combination of parameters. It was
found that out-of-straightness, residual stresses, Young's modulus of elasticity, and the
unconnected gusset plate length do not have a great effect on the load carrying capacity. The
most significant parameter is gusset plate thickness with the gusset plate width being the
second most important parameter. An empirical design equation is proposed and illustrated
by two design examples.
vii
To My Parents and My Sisters
for their love, suppurt and encouragement
I wish to begin with expressing my sincere gratitude to my supenisor. Dr. M. C.
Temple. for the excellent guidance. effort. inspirat ion. and continuous encouragement which
he so mthusiastically provided throughout the course of my research studies.
My thanks are also estended to Dr. G. Abdel-Sayed for his open door policy
regarding any questions or concerns pertaining to this study and for his encouragement and
assistance throughout my doctoral pro,o ram.
I would like to thank the faculty and staff of the Depanment of Civil and
Environmental Engineering as well as the computer consultants of the Computing Scr\ ices
at the University of Windsor for their assistance during this research. Special thanks are also
due to Mr. Richard Clark. the laboratory technician. Mr. Dieter Licbsch and the members of
the Technical Suppon Centre for their assistance in the preparation and testing of the
specimens during the experimental pan of this study.
I would also like to acknowledge the fmancial support pro\.ided by the Natural
Sciences and Engineering Research Council of Canada.
Last. but not least. the author wishes to thank his family for their great support and
encouragement throughout the course of this study.
Finally. to all the staff and faculty in the Civil and Environmental Engineering
Department at the University of Windsor. I wish you continued success.
.
Page No
LISTOFTABLES ............................................
LIST OF FIGURES ............................................
X\.I
LIST OF SYMBOLS .......................................... ssii
CHAPTER I ISTRODUCTIOS ................................ 1
1.1General ............................................. 1
1.2 Design Practices ....................................... -1
1.3 Weld Patterns ......................................... 4
1 .-RI esearch Objectives .................................... 5
1.5 Research Program ..................................... 6
CHAPTER I1 LITER4TUR.E REVIEW ..........................
2.1 Previous Research .....................................
2.1.1 Stability of Axially Loaded Single Angles ..............
2.1 -2 Eccentrically Loaded Single Angles ..................
2.1.2.1 Leigh and Galambos ( 1972) ....................
2.1.2.2 Woolcock and Kitipornchai ( 1986) ...............
.
2.1.2.3 Elgaalyet a1 . (1991 1992) .....................
2.1.2.4 Adluri and Madupla ( i 992) ....................
2.2 Design Practices .......................................
2.2.1 Simple-Column Design Practice .....................
2.2.2 Beam-Column Design Practice ......................
2.2.3 The ASCE Standard. Design of Latticed Steel Transmission
Structures ( I99 1 ) ..................................
2.2.4 Evaluation of Design Practices in Light of Trahair et a1 .
( 1969) Test Results ..................................