4 - Memorial University of Newfoundland DAI

where
[MI' = Im.1 t lTPlm,.lITI,
IKI' = [4.l- [9.1[4.1-'[k.ml. and
F' = t [llTL(t).
Here, [m and [K]. are the condensed mas and stillncas mntriccs, rcspn-
tively; P is theequivalently lumped nodal force vector; wililc zm is a calt!snrt
vector involving fewer variables than the original low vcclor in equation8
(3.49). Since it requires less CPU time and core storagr, the solulion ol
equation (3.54) ia rrlativoly simple.
Implementation: Beesuse the slave DOF vnstly oulntmmbcr thc ~nsvler
DOF, inverting [k.,] is CPU intensive. This problcm could hc ovarearno
by applying the following =usetion lo the flexibility matrix-i.c., fro,,, tile
output of thestatic analysis:
the ribht hand side matrix in the above expmion iu lhe lnmilirr gjd,d
flexibility malrix. Aa a result:
Based on the above expression,
and
- [&.I-'[k..l = Iamnl-'l~nnl = [TI.
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