Three-Dimensional Static and Dynamic Analysis of Structures
shk yN A Physical Approach With Emphasis on Earthquake Engineering
wXR7Ifrv !l9i)6W by
=Ju%3ptH0 Edward L. Wilson
F ?N+ __o Professor Emeritus of Structural Engineering
2I[(UMI$7 University of California at Berkeley
S =5br :<p3L!?8y Copyright Computers and Structures, Inc., 1996-2001
(e"\%p` The CSI Logo is a trademark of Computers and Structures, Inc.
c`Q#4e]%_ SAP90, SAP2000, SAFE, FLOOR and ETABS are trademarks of
\d)HwO Computers and Structures, Inc.
%ztv.K(8 ISBN 0-923907-00-9
\Gl>$5n p >mAi/TZC Preface To Third Edition
}Y~ <|vZ This edition of the book contains corrections and additions to the July 1998 edition.
L l$,"}0T Most of the new material that has been added is in response to questions and comments
D[p_uDIz from the users of SAP2000, ETABS and SAFE.
qs$w9 I Chapter 22 has been written on the direct use of absolute earthquake displacement
X_HU?Q_N loading acting at the base of the structure. Several new types of numerical errors for
q2+`a;_S absolute displacement loading have been identified. First, the fundamental nature of
MSqW { displacement loading is significantly different from the base acceleration loading
~ o8 traditionally used in earthquake engineering. Second, a smaller integration time step is
+b
sc3 required to define the earthquake displacement and to solve the dynamic equilibrium
]]F e:> equations. Third, a large number of modes are required for absolute displacement
}'`iJ b\ loading to obtain the same accuracy as produced when base acceleration is used as the
61SbBJ6[ loading. Fourth, the 90 percent mass participation rule, intended to assure accuracy of
f]4j7K!e] the analysis, does not apply for absolute displacement loading. Finally, the effective
|S6L[Uo modal damping for displacement loading is larger than when acceleration loading is
*-eDU T|O used.
~'#yH#o To reduce those errors associated with displacement loading, a higher order integration
byJR6f method based on a cubic variation of loads within a time step is introduced in Chapter
b3 NEYn 13. In addition, static and dynamic participation factors have been defined that allow the
dBm!`;r4 structural engineer to minimize the errors associated with displacement type loading. In
mXwDB)O{) addition, Chapter 19 on viscous damping has been expanded to illustrate the physical
\yhj {QS.k effects of modal damping on the results of a dynamic analysis.
0<[g 7BbR Appendix H, on the speed of modern personal computers, has been updated. It is now
@1vpkB~ w possible to purchase a personal computer for approximately $1,500 that is 25 times
jR[b 7s faster than a $10,000,000 CRAY computer produced in 1974.
BMdcW
MYU\ Several other additions and modifications have been made in this printing. Please send
]q`'l_O your comments and questions to
ed@csiberkeley.com.
j&-<e 7O= Edward L. Wilson
ooA%/ April 2000
