*HEADING
:  LARGE STRAIN VISCOELASTICITY - VOLUMETRIC RELAXATION - CPE4
 THESE MATERIAL CONSTANTS IN COMPRESSION PRODUCE NEGATIVE POISSON RATIO
*NODE
1,
2,10.
3,10.,5.,
4,0.,5.,
*ELEMENT,TYPE=CPE4,ELSET=ONE
1,1,2,3,4
*SOLID SECTION,ELSET=ONE,MATERIAL=SIMPLE
1., 
*MATERIAL,NAME=SIMPLE
*HYPERELASTIC,N=1,MODULI=INSTANTANEOUS
8.,2.,0.1
*VISCOELASTIC,TIME=PRONY
0.,0.5,3.
*BOUNDARY
1,1,2
2,2,2
4,1,1
*STEP,NLGEOM
*VISCO
2.,10.,2.,10.,
*BOUNDARY
3,1,1,-2.
2,1,1,-2.
4,2,2,-1.
3,2,2,-1.
*EL FILE,F=1
S,E,CE,CEP
*NODE FILE,F=1
U,RF
*END STEP