Three-Dimensional Static and Dynamic Analysis of Structures
ZKy)F-yX A Physical Approach With Emphasis on Earthquake Engineering
rH*1bDL kW#,o 9f\ by
3 <}\{ jT Edward L. Wilson
~A@T_ *0 Professor Emeritus of Structural Engineering
;wo University of California at Berkeley
f++MH]I; )[fjZG[ Copyright Computers and Structures, Inc., 1996-2001
%LyZaU_sB The CSI Logo is a trademark of Computers and Structures, Inc.
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'L" SAP90, SAP2000, SAFE, FLOOR and ETABS are trademarks of
I@Cq< :+(3 Computers and Structures, Inc.
wpg O09 ISBN 0-923907-00-9
PD #9Z=Hj <Qg).n >;z Preface To Third Edition
\9" This edition of the book contains corrections and additions to the July 1998 edition.
,LI$=lJ@ Most of the new material that has been added is in response to questions and comments
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mc< n from the users of SAP2000, ETABS and SAFE.
x }\x3U Chapter 22 has been written on the direct use of absolute earthquake displacement
N>ncv loading acting at the base of the structure. Several new types of numerical errors for
aa|u *afWQ absolute displacement loading have been identified. First, the fundamental nature of
#1Zqq([@ displacement loading is significantly different from the base acceleration loading
gu?e %]X3 traditionally used in earthquake engineering. Second, a smaller integration time step is
}9:( l required to define the earthquake displacement and to solve the dynamic equilibrium
D5Zgi! equations. Third, a large number of modes are required for absolute displacement
/{1s U}k- loading to obtain the same accuracy as produced when base acceleration is used as the
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cK>@l loading. Fourth, the 90 percent mass participation rule, intended to assure accuracy of
|Gp!#D0b the analysis, does not apply for absolute displacement loading. Finally, the effective
/x%h@Cn! modal damping for displacement loading is larger than when acceleration loading is
C@x\ZG5rA used.
\c ')9g@ To reduce those errors associated with displacement loading, a higher order integration
),{v method based on a cubic variation of loads within a time step is introduced in Chapter
$4>(} 13. In addition, static and dynamic participation factors have been defined that allow the
;R5@]Hg6q structural engineer to minimize the errors associated with displacement type loading. In
rX7GVg@H addition, Chapter 19 on viscous damping has been expanded to illustrate the physical
Zv]'9,cbk effects of modal damping on the results of a dynamic analysis.
m^k $Z0 Appendix H, on the speed of modern personal computers, has been updated. It is now
FOPfo b[ possible to purchase a personal computer for approximately $1,500 that is 25 times
o*MiKgQ& faster than a $10,000,000 CRAY computer produced in 1974.
Q}; n%&n& Several other additions and modifications have been made in this printing. Please send
:g%hT$,]3b your comments and questions to
ed@csiberkeley.com.
J#.f%VJ Edward L. Wilson
n!aA < April 2000
