Three-Dimensional Static and Dynamic Analysis of Structures
Mb(a I!;A A Physical Approach With Emphasis on Earthquake Engineering
6"W~%FSJX Py8<db% by
+cVnF&@$ Edward L. Wilson
$Y4;Xe= Professor Emeritus of Structural Engineering
}GCt)i_ University of California at Berkeley
We T s va+ dZ7+Iw;m Copyright Computers and Structures, Inc., 1996-2001
|mfQmFF The CSI Logo is a trademark of Computers and Structures, Inc.
[EJ[Gg0m SAP90, SAP2000, SAFE, FLOOR and ETABS are trademarks of
j [h4F"`- Computers and Structures, Inc.
Xo*=iD$Jys ISBN 0-923907-00-9
~o+HAc `=v y$At$i>u Preface To Third Edition
mq?5|` This edition of the book contains corrections and additions to the July 1998 edition.
G8lR_gD"! Most of the new material that has been added is in response to questions and comments
oP".>g-. from the users of SAP2000, ETABS and SAFE.
+M6qbIO Chapter 22 has been written on the direct use of absolute earthquake displacement
#<bt}Th t loading acting at the base of the structure. Several new types of numerical errors for
iG*/m><- absolute displacement loading have been identified. First, the fundamental nature of
DH_Mll > displacement loading is significantly different from the base acceleration loading
"S43: VH traditionally used in earthquake engineering. Second, a smaller integration time step is
+?~'K&@ required to define the earthquake displacement and to solve the dynamic equilibrium
+QIM~ tt) equations. Third, a large number of modes are required for absolute displacement
XnQo0
R.PW loading to obtain the same accuracy as produced when base acceleration is used as the
v3+ \A q loading. Fourth, the 90 percent mass participation rule, intended to assure accuracy of
lV-7bZ the analysis, does not apply for absolute displacement loading. Finally, the effective
u> <gmp& modal damping for displacement loading is larger than when acceleration loading is
Qc z7IA used.
$@t-O or; To reduce those errors associated with displacement loading, a higher order integration
B8_ w3;x method based on a cubic variation of loads within a time step is introduced in Chapter
*Ri?mEv
hF 13. In addition, static and dynamic participation factors have been defined that allow the
pI
|; structural engineer to minimize the errors associated with displacement type loading. In
u|7d_3 :: addition, Chapter 19 on viscous damping has been expanded to illustrate the physical
OC F\ *Sx effects of modal damping on the results of a dynamic analysis.
6v0^'} Appendix H, on the speed of modern personal computers, has been updated. It is now
+'?p $@d possible to purchase a personal computer for approximately $1,500 that is 25 times
A:EF#2) g faster than a $10,000,000 CRAY computer produced in 1974.
K^k1]!W= Several other additions and modifications have been made in this printing. Please send
85l 1 your comments and questions to
ed@csiberkeley.com.
A}sb 2P Edward L. Wilson
. oUaq|O April 2000
