Three-Dimensional Static and Dynamic Analysis of Structures
ZzpUUH/r A Physical Approach With Emphasis on Earthquake Engineering
~P,lz!h e_ (D&3G;0tK by
k FD; i Edward L. Wilson
MYvY]Jx3 Professor Emeritus of Structural Engineering
n\'4 University of California at Berkeley
"|
g>'w M* xn(kKB . Copyright Computers and Structures, Inc., 1996-2001
?4&e;83_#y The CSI Logo is a trademark of Computers and Structures, Inc.
(OL4Ex'] SAP90, SAP2000, SAFE, FLOOR and ETABS are trademarks of
|F[+k e Computers and Structures, Inc.
k5e;fA/w ISBN 0-923907-00-9
]^7@}Ce_ {9pZ)tB Preface To Third Edition
[kB7@o This edition of the book contains corrections and additions to the July 1998 edition.
`25yE/ Most of the new material that has been added is in response to questions and comments
69NeQ$]( from the users of SAP2000, ETABS and SAFE.
{duz\k2 Chapter 22 has been written on the direct use of absolute earthquake displacement
Y =I' czg loading acting at the base of the structure. Several new types of numerical errors for
A,<E\ absolute displacement loading have been identified. First, the fundamental nature of
<2x^slx)? displacement loading is significantly different from the base acceleration loading
i$#;Kpb`^ traditionally used in earthquake engineering. Second, a smaller integration time step is
W,n!3:7 s required to define the earthquake displacement and to solve the dynamic equilibrium
qgHWUwr+n equations. Third, a large number of modes are required for absolute displacement
783,s_ loading to obtain the same accuracy as produced when base acceleration is used as the
p38-l'{# loading. Fourth, the 90 percent mass participation rule, intended to assure accuracy of
$GcqBg-Hi the analysis, does not apply for absolute displacement loading. Finally, the effective
-f^tE, - modal damping for displacement loading is larger than when acceleration loading is
P4'Q/Sj used.
~jk|4`I?T To reduce those errors associated with displacement loading, a higher order integration
$( kF# method based on a cubic variation of loads within a time step is introduced in Chapter
LA5( sp@O 13. In addition, static and dynamic participation factors have been defined that allow the
p27~>xQ structural engineer to minimize the errors associated with displacement type loading. In
& h)yro addition, Chapter 19 on viscous damping has been expanded to illustrate the physical
SHgN~ Um effects of modal damping on the results of a dynamic analysis.
`UaD6Mc<Mz Appendix H, on the speed of modern personal computers, has been updated. It is now
v{N`.~,^ possible to purchase a personal computer for approximately $1,500 that is 25 times
!i}w~U< faster than a $10,000,000 CRAY computer produced in 1974.
s^9Voi.y Several other additions and modifications have been made in this printing. Please send
Y\P8 v your comments and questions to
ed@csiberkeley.com.
i9|Sa6vuI Edward L. Wilson
'GWN~ 5 April 2000
