Three-Dimensional Static and Dynamic Analysis of Structures
_Q7]Dw/w\ A Physical Approach With Emphasis on Earthquake Engineering
hpo*5Va lA n^ )EL by
7towjw r Edward L. Wilson
Tbg Ir Professor Emeritus of Structural Engineering
U+:Mu]97 University of California at Berkeley
VM w[M^ [FeN(8hGS Copyright Computers and Structures, Inc., 1996-2001
*|6 *jU The CSI Logo is a trademark of Computers and Structures, Inc.
ICzcV };$ SAP90, SAP2000, SAFE, FLOOR and ETABS are trademarks of
lF ~!F<^9 Computers and Structures, Inc.
R /l/GNm ISBN 0-923907-00-9
hI,+J> Vsd4; Preface To Third Edition
=h[;'v{ This edition of the book contains corrections and additions to the July 1998 edition.
?gG%FzfQ/ Most of the new material that has been added is in response to questions and comments
VlS`m,:{ from the users of SAP2000, ETABS and SAFE.
R{q<V uN Chapter 22 has been written on the direct use of absolute earthquake displacement
w QojmmQ loading acting at the base of the structure. Several new types of numerical errors for
D;6C2>U~L absolute displacement loading have been identified. First, the fundamental nature of
E=t^I/f)E displacement loading is significantly different from the base acceleration loading
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traditionally used in earthquake engineering. Second, a smaller integration time step is
]*<!|;q required to define the earthquake displacement and to solve the dynamic equilibrium
! l"*DR equations. Third, a large number of modes are required for absolute displacement
%FLe@.Ep{D loading to obtain the same accuracy as produced when base acceleration is used as the
()z n8_z loading. Fourth, the 90 percent mass participation rule, intended to assure accuracy of
~z7Fz"o< the analysis, does not apply for absolute displacement loading. Finally, the effective
B
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<%S[6*6U used.
fK+ [r1^ To reduce those errors associated with displacement loading, a higher order integration
rS_pv=0S method based on a cubic variation of loads within a time step is introduced in Chapter
fkD-mRKw 13. In addition, static and dynamic participation factors have been defined that allow the
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0 structural engineer to minimize the errors associated with displacement type loading. In
[#+klP$ addition, Chapter 19 on viscous damping has been expanded to illustrate the physical
^_k`@SU effects of modal damping on the results of a dynamic analysis.
rmPJid[8B~ Appendix H, on the speed of modern personal computers, has been updated. It is now
I36ClOG possible to purchase a personal computer for approximately $1,500 that is 25 times
q0(-"}2l faster than a $10,000,000 CRAY computer produced in 1974.
NGkWr Several other additions and modifications have been made in this printing. Please send
QT\" r T9# your comments and questions to
ed@csiberkeley.com.
@^n E^; Edward L. Wilson
dm"|\ 7 April 2000
