Three-Dimensional Static and Dynamic Analysis of Structures
K/RQ-xd 4 A Physical Approach With Emphasis on Earthquake Engineering
hoxn! x$? { zoUU by
&tY3nr Edward L. Wilson
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3Lm0> Professor Emeritus of Structural Engineering
u2HkAPhD University of California at Berkeley
pAS!;t= n, rQiX 7 Copyright Computers and Structures, Inc., 1996-2001
KDwz!:ye The CSI Logo is a trademark of Computers and Structures, Inc.
ht c& !m SAP90, SAP2000, SAFE, FLOOR and ETABS are trademarks of
$ q*kD#;mh Computers and Structures, Inc.
-1Y9-nn[m ISBN 0-923907-00-9
MLg<YL pT]M ]/y/: Preface To Third Edition
& pwSd This edition of the book contains corrections and additions to the July 1998 edition.
#!p=P<4M
Most of the new material that has been added is in response to questions and comments
fr'M)ox1 from the users of SAP2000, ETABS and SAFE.
)#-27Y Chapter 22 has been written on the direct use of absolute earthquake displacement
'Z2:u!E loading acting at the base of the structure. Several new types of numerical errors for
D d|}LV absolute displacement loading have been identified. First, the fundamental nature of
T! $7:% D displacement loading is significantly different from the base acceleration loading
zb9^ii$g traditionally used in earthquake engineering. Second, a smaller integration time step is
".L+gn}u- required to define the earthquake displacement and to solve the dynamic equilibrium
^q6H
=Dl equations. Third, a large number of modes are required for absolute displacement
Tk s;,C loading to obtain the same accuracy as produced when base acceleration is used as the
{9TWPB /> loading. Fourth, the 90 percent mass participation rule, intended to assure accuracy of
Ao HA+>&U the analysis, does not apply for absolute displacement loading. Finally, the effective
.4={K)kz|F modal damping for displacement loading is larger than when acceleration loading is
5zJkPki used.
)
Kfk\ To reduce those errors associated with displacement loading, a higher order integration
'$Jt }O method based on a cubic variation of loads within a time step is introduced in Chapter
eydV WVN 13. In addition, static and dynamic participation factors have been defined that allow the
J5L P#o(V structural engineer to minimize the errors associated with displacement type loading. In
$mm =$. addition, Chapter 19 on viscous damping has been expanded to illustrate the physical
r` u}n effects of modal damping on the results of a dynamic analysis.
}_XW?^/8 Appendix H, on the speed of modern personal computers, has been updated. It is now
sh.xp8^)^> possible to purchase a personal computer for approximately $1,500 that is 25 times
t
K;E&: faster than a $10,000,000 CRAY computer produced in 1974.
/=Ug}% . Several other additions and modifications have been made in this printing. Please send
P# 2&?.d\ your comments and questions to
ed@csiberkeley.com.
2=ZR}8}9Q: Edward L. Wilson
bb;fV April 2000
