Three-Dimensional Static and Dynamic Analysis of Structures
* crw^e A Physical Approach With Emphasis on Earthquake Engineering
ij)Cm]4(2 .{rbw9 by
)BV=|,j Edward L. Wilson
$@[)nvV\ Professor Emeritus of Structural Engineering
I^0 t2[M University of California at Berkeley
6n w&$I XdIah<F2 Copyright Computers and Structures, Inc., 1996-2001
b 6W#SpCF The CSI Logo is a trademark of Computers and Structures, Inc.
F$6? t.@J SAP90, SAP2000, SAFE, FLOOR and ETABS are trademarks of
H*U` Computers and Structures, Inc.
Q9y*: ISBN 0-923907-00-9
$Lq:=7&LRn =Lw3
\5l Preface To Third Edition
c;V D}UD' This edition of the book contains corrections and additions to the July 1998 edition.
[ #]jC[ Most of the new material that has been added is in response to questions and comments
j=3-Qk`"/| from the users of SAP2000, ETABS and SAFE.
7!d$M{0" Chapter 22 has been written on the direct use of absolute earthquake displacement
~Yl$I, loading acting at the base of the structure. Several new types of numerical errors for
23E 0~O absolute displacement loading have been identified. First, the fundamental nature of
W8/(;K`/ displacement loading is significantly different from the base acceleration loading
8 lS($@@{ traditionally used in earthquake engineering. Second, a smaller integration time step is
dK # h<q1 required to define the earthquake displacement and to solve the dynamic equilibrium
$pu3Ig$^ equations. Third, a large number of modes are required for absolute displacement
D!l8l49hLu loading to obtain the same accuracy as produced when base acceleration is used as the
p?Sl}A@` loading. Fourth, the 90 percent mass participation rule, intended to assure accuracy of
0$F f#8 the analysis, does not apply for absolute displacement loading. Finally, the effective
dq 8+m(7k modal damping for displacement loading is larger than when acceleration loading is
5~xeO@%I used.
k :0P+d To reduce those errors associated with displacement loading, a higher order integration
ER<e X4oU method based on a cubic variation of loads within a time step is introduced in Chapter
m`9^.>]P 13. In addition, static and dynamic participation factors have been defined that allow the
rt.[,m structural engineer to minimize the errors associated with displacement type loading. In
i_Ar<9a~ addition, Chapter 19 on viscous damping has been expanded to illustrate the physical
u5 E/m effects of modal damping on the results of a dynamic analysis.
M.k|bh8 Appendix H, on the speed of modern personal computers, has been updated. It is now
T +\ B'" possible to purchase a personal computer for approximately $1,500 that is 25 times
t,Q'S`eTU faster than a $10,000,000 CRAY computer produced in 1974.
d^SE)/j Several other additions and modifications have been made in this printing. Please send
Ao *FcrXN your comments and questions to
ed@csiberkeley.com.
AF[>fMI Edward L. Wilson
h ]}`@M" April 2000
