Three-Dimensional Static and Dynamic Analysis of Structures
d Im m}, A Physical Approach With Emphasis on Earthquake Engineering
y@I"Hk<T I$$!YMm.N by
''G @ n* Edward L. Wilson
eW/Hn Professor Emeritus of Structural Engineering
$3>|R lxYA University of California at Berkeley
~&kV ;6?K&}J)- Copyright Computers and Structures, Inc., 1996-2001
Z_%>yqD C The CSI Logo is a trademark of Computers and Structures, Inc.
qcqf9g SAP90, SAP2000, SAFE, FLOOR and ETABS are trademarks of
lI9 3{!+> Computers and Structures, Inc.
Oaui@q
ISBN 0-923907-00-9
a^BD55d ? WVZ\4y Preface To Third Edition
4"{q|~&=:$ This edition of the book contains corrections and additions to the July 1998 edition.
b> | oU Most of the new material that has been added is in response to questions and comments
H
X8q+ from the users of SAP2000, ETABS and SAFE.
%llG/]q# Chapter 22 has been written on the direct use of absolute earthquake displacement
y^ohns5{ loading acting at the base of the structure. Several new types of numerical errors for
XZhhr1-<a absolute displacement loading have been identified. First, the fundamental nature of
%Xn)$Ti ~< displacement loading is significantly different from the base acceleration loading
3iB8QO;pp traditionally used in earthquake engineering. Second, a smaller integration time step is
7 UR)4dYA required to define the earthquake displacement and to solve the dynamic equilibrium
3hkA`YSYt equations. Third, a large number of modes are required for absolute displacement
;Bm{_$hf= loading to obtain the same accuracy as produced when base acceleration is used as the
?S"xR0 * loading. Fourth, the 90 percent mass participation rule, intended to assure accuracy of
p~t $ll0s the analysis, does not apply for absolute displacement loading. Finally, the effective
pxgv(:Tw modal damping for displacement loading is larger than when acceleration loading is
rVLA"x 9u used.
tZJKB1#WbP To reduce those errors associated with displacement loading, a higher order integration
F)C8 LH method based on a cubic variation of loads within a time step is introduced in Chapter
QeGU]WU{ 13. In addition, static and dynamic participation factors have been defined that allow the
~/t# J structural engineer to minimize the errors associated with displacement type loading. In
"xWC49 addition, Chapter 19 on viscous damping has been expanded to illustrate the physical
bkb}M)C effects of modal damping on the results of a dynamic analysis.
E>&dG:3no Appendix H, on the speed of modern personal computers, has been updated. It is now
"QMHY\C possible to purchase a personal computer for approximately $1,500 that is 25 times
`+U-oqs faster than a $10,000,000 CRAY computer produced in 1974.
3'8~H]<W Several other additions and modifications have been made in this printing. Please send
*fE5Z;!} your comments and questions to
ed@csiberkeley.com.
epQ 7@9,Q Edward L. Wilson
l!
GPOmf9` April 2000
