Three-Dimensional Static and Dynamic Analysis of Structures
rjffp U A Physical Approach With Emphasis on Earthquake Engineering
H )51J:4 XG uxd by
]p8 zT|bv Edward L. Wilson
kmUL^vF Professor Emeritus of Structural Engineering
}u9#S University of California at Berkeley
+ GJPj(S 80zpR U" Copyright Computers and Structures, Inc., 1996-2001
T;G<62`.h The CSI Logo is a trademark of Computers and Structures, Inc.
]A ;.}1' SAP90, SAP2000, SAFE, FLOOR and ETABS are trademarks of
7fI2b,~ Computers and Structures, Inc.
cJMi`PQ; ISBN 0-923907-00-9
+4$][3. ^Q6?T(%$ Preface To Third Edition
\TZSn1isZX This edition of the book contains corrections and additions to the July 1998 edition.
v,C~5J3h) Most of the new material that has been added is in response to questions and comments
G6QD`ED from the users of SAP2000, ETABS and SAFE.
I8 a3: ) Chapter 22 has been written on the direct use of absolute earthquake displacement
Jd^Lnp6? loading acting at the base of the structure. Several new types of numerical errors for
VKkvf"X absolute displacement loading have been identified. First, the fundamental nature of
zYrJ Hn#vB displacement loading is significantly different from the base acceleration loading
1f vN[ traditionally used in earthquake engineering. Second, a smaller integration time step is
LSo*JO6 required to define the earthquake displacement and to solve the dynamic equilibrium
]#Cc 7wa
equations. Third, a large number of modes are required for absolute displacement
#dKy{Q3he loading to obtain the same accuracy as produced when base acceleration is used as the
/ej[oR loading. Fourth, the 90 percent mass participation rule, intended to assure accuracy of
HKr}" `I. the analysis, does not apply for absolute displacement loading. Finally, the effective
C1'y6{ ,@ modal damping for displacement loading is larger than when acceleration loading is
xP_/5N=f used.
x3g4 r_ To reduce those errors associated with displacement loading, a higher order integration
%&_^I* method based on a cubic variation of loads within a time step is introduced in Chapter
XmD(&3; v- 13. In addition, static and dynamic participation factors have been defined that allow the
81"` B2 structural engineer to minimize the errors associated with displacement type loading. In
}toe '6 addition, Chapter 19 on viscous damping has been expanded to illustrate the physical
;DSH$'1i effects of modal damping on the results of a dynamic analysis.
PW|=IPS Appendix H, on the speed of modern personal computers, has been updated. It is now
CIz0Gjtx6m possible to purchase a personal computer for approximately $1,500 that is 25 times
^*i0~_ faster than a $10,000,000 CRAY computer produced in 1974.
#C PLvg# Several other additions and modifications have been made in this printing. Please send
S.4+tf 7+ your comments and questions to
ed@csiberkeley.com.
/!2`pv Edward L. Wilson
H0#=oJr$)W April 2000
