/solu
/com First phase of linear perturbation
antype,static,restart,,,perturb! Restart from the last substep of the rigid rotationperturb,modal! Set linear perturbed modal analysis
solve,elform! Execute 1st phase of linear perturbation, recovering Kt of NLGEOM,on
/com Second phase of linear perturbationoutres,all,all
modopt,lanb,2! Solve for first 2 modes by using block lanczos
mxpand,2,,,yes! Expand mode at the same time
solve! Execute 2nd phase of linear perturbation: modal analysis
finish
/post1
file,,rstp! Use *.rstp file to review results from linear perturbation
set,list! List 2 eigenmodesset,1,1! List strains and stresses of element 1 in the first mode
esel,s,elem,,1
rsys,0! List results in global coordinates
presol,s
presol,epto
rsys,solu! List results in element coordinates
presol,s
presol,epto
finishExample 9.4: Contact Status Control in a Linear Perturbation Modal Analysis
/filname,test1
!********** CASE 1 **********
/prep7
et,1,182
r,1,0.1
mp,ex,1,30e6
mp,dens,1,7.324
mp,prxy,,0.3
csys,1
pcirc,10,5,0,90
pcirc,10,15,40,50
allsel,all
esize,0.7
cyclic! A cyclic symmetric static problem
mshkey,1
amesh,all
allsel,all
!********** Original contact definition **********
et,2,172
mat,2
mp,mu,2,0.0001
keyopt,2,4,2
keyopt,2,2,0! Penalty function
keyopt,2,12,2! No-Separation contact (sliding allowed)
keyopt,2,5,1
type,2
real,2
lsel,s,line,,7Release 15.0 - © SAS IP, Inc. All rights reserved. - Contains proprietary and confidential informationLinear Perturbation Analysis