*heading
pressdepper2d.inp
*preprint,model=yes,contact=yes,history=yes
*node, nset=all
1,0.,0.
2,1.,0.
3,1.,1.
4,0.,1.
5,-1.,-1.1
6,2.,-1.1
7,2.,-0.1
8,-1.,-0.1
*element, type=cps4,elset=eall
1, 1,2,3,4
2, 5,6,7,8
*solid section,material=mat1,elset=eall
1.,
*material,name=mat1
*density
7800.
*elastic
2.e11,0.3
*surface, name=surf1, type=element
1, s1
*surface, name=surf2, type=element
2, s3
*contact pair,interaction=inter,type=node to surface,small sliding
surf1, surf2
*surface interaction, name=inter
1.
*surface behavior,penalty
*friction
0.1,
**
** step 1, natural eigenpairs; no prestress
*step,name=frequency1
*frequency,eigensolver=subspace, SIM=NO
6,
*boundary
4, 1,1
4, 2,2,0.
3, 2,2,0.
5, 1,2
6, 2,2
*end step
**
** step 2
*step,name=general1
*static
1.,1.
*boundary
4, 1,1
4, 2,2,-0.2
3, 2,2,-0.2
5, 1,2
6, 2,2
*print,solve=no
*output,history,freq=0
*output,field
*node output
u,
*contact output
cstress,
*node print
u,
*el print
s,
*contact print
*output,history,freq=0
*output,field,variable=preselect
*node output
u,
*contact output
cstress,cdisp
*end step
**
** step 3
*step,name=frequency2
** preloaded; reference eigenpairs; eigenvalues should be higher than for step 1
*frequency,eigensolver=subspace, SIM=NO
6,
*end step
**
** step 4
*step,name=frequency3
*frequency,eigensolver=subspace, SIM=NO
6,
** eigenvalues should be less than for step 3
*contact controls,pressure dependent perturbation=1.e11,slave=surf1,master=surf2
0.
*end step
**
** step 5
*step,name=frequency4
*frequency,eigensolver=subspace, SIM=NO
6,
** The elopw printed contact stiffness should be 10 times smaller than for step 4
** spectrum should be less than of step 4
*contact controls,pressure dependent perturbation=1.e12
0.
*end step
** step 6
*step,name=frequency5
*frequency,eigensolver=lanczos, SIM=NO
6,
** spectrum should be the same as of step 4
*contact controls,pressure dependent perturbation=1.e11
0.
*end step
**
** step 7
*step,name=general2
*static
1.,1.
*boundary
4, 1,1
4, 2,2,-0.3
3, 2,2,-0.3
5, 1,2
6, 2,2
*end step
**
** step 8
*step,name=frequency6
*frequency,eigensolver=lanczos, SIM=NO
6,
** spectrum should differ from step 3.
*contact controls,pressure dependent perturbation=0.,slave=surf1,master=surf2
0.
*end step
**
** step 9
*step,name=frequency7
** spectrum should be the same as for step 8.
*frequency,eigensolver=subspace, SIM=NO
6,
*end step
**
** step 10
*step,name=frequency8
*frequency,eigensolver=lanczos, SIM=NO
6,
** Remove all contact constraints; spectrum should be
** the same as for step 1 (nlgeom=no in effect).
*contact controls,pressure dependent perturbation=1.e15
*end step