Three-Dimensional Static and Dynamic Analysis of Structures
q<09]i A Physical Approach With Emphasis on Earthquake Engineering
R$:-~< O ' @!&{N by
F-;J N Edward L. Wilson
tiK M+
;C Professor Emeritus of Structural Engineering
O/~T+T% University of California at Berkeley
bQaRl=:[: 8SjCU+V Copyright Computers and Structures, Inc., 1996-2001
6N@=*0kh- The CSI Logo is a trademark of Computers and Structures, Inc.
Id=20og SAP90, SAP2000, SAFE, FLOOR and ETABS are trademarks of
[c?0Q3F Computers and Structures, Inc.
iJTG +gx ISBN 0-923907-00-9
;As~T GiT b<u\THy# Preface To Third Edition
P27Ot1px This edition of the book contains corrections and additions to the July 1998 edition.
n_QuuUB Most of the new material that has been added is in response to questions and comments
,HjJ jpE from the users of SAP2000, ETABS and SAFE.
TK5$-6k Chapter 22 has been written on the direct use of absolute earthquake displacement
k \OZ'dS loading acting at the base of the structure. Several new types of numerical errors for
K$S0h-?9]O absolute displacement loading have been identified. First, the fundamental nature of
xg p)G!
displacement loading is significantly different from the base acceleration loading
yhH2b:nY(9 traditionally used in earthquake engineering. Second, a smaller integration time step is
4&*lpl*N required to define the earthquake displacement and to solve the dynamic equilibrium
uX 7L1~s- equations. Third, a large number of modes are required for absolute displacement
5Q10Ohh loading to obtain the same accuracy as produced when base acceleration is used as the
FWW4n_74 loading. Fourth, the 90 percent mass participation rule, intended to assure accuracy of
ZX_QnSNZ? the analysis, does not apply for absolute displacement loading. Finally, the effective
rc=E%Qv%? modal damping for displacement loading is larger than when acceleration loading is
mI lg=8: used.
392V\qtS To reduce those errors associated with displacement loading, a higher order integration
} 9@rhW method based on a cubic variation of loads within a time step is introduced in Chapter
7? fgcb3 13. In addition, static and dynamic participation factors have been defined that allow the
^%\a,~ structural engineer to minimize the errors associated with displacement type loading. In
7F"ljkN1S addition, Chapter 19 on viscous damping has been expanded to illustrate the physical
,+i^]yF3j effects of modal damping on the results of a dynamic analysis.
48xgl1R(j Appendix H, on the speed of modern personal computers, has been updated. It is now
| R,dsBd possible to purchase a personal computer for approximately $1,500 that is 25 times
>k
@t.PeoV faster than a $10,000,000 CRAY computer produced in 1974.
PF4[;E S' Several other additions and modifications have been made in this printing. Please send
^*P?gG your comments and questions to
ed@csiberkeley.com.
A ;U c&G Edward L. Wilson
01n!T2;yW} April 2000
