*HEADING
UNIAXIAL STRETCHING OF A RUBBER SHEET W/ A CIRC. HOLE - VISCOELASTIC  
BIDERMAN STRAIN ENERGY FUNCTION
VISCOELASTIC RELAXATION AFTER LOADING TO 1/2 STRESS LEVEL
TEST *VISCO STABILIZATION
*NODE
1,0.25,0.
33,0.,0.25
1601,3.25,0.
1617,3.25,3.25
1633,0.,3.25
10000,0.,0.
*NGEN,LINE=C
1,33,1,10000
*NGEN
1601,1617,1
1617,1633,1
*NSET,NSET=DOWN,GENERATE
1,33,1
*NSET,NSET=UP,GENERATE
1601,1633,1
*NFILL, BIAS=0.75, TWO STEP
DOWN,UP,8,200
*NSET,NSET=TOP,GENERATE
1617,1633,2
*NSET,NSET=BOTTOM,GENERATE
1,1601,200
*NSET,NSET=LEFT,GENERATE
33,1633,200
*NSET,NSET=RMPC,GENERATE
1603,1617,2
*NSET,NSET=ONE
1601, 
*ELEMENT,TYPE=CPS8R
1,1,401,405,5,201,403,205,3
*ELGEN,ELSET=ALLE
1,4,400,1,8,4,4
*ELSET,ELSET=TOPE
20,24,28,32
*ELSET,ELSET=LEFTE
29,30,31,32
*BOUNDARY
BOTTOM,2
TOP,2
LEFT,1
*EQUATION
2, 
RMPC,1,1.,1601,1,-1.
*MATERIAL,NAME=BIDERMAN
*HYPERELASTIC,N=3,MODULI=INSTANTANEOUS
27.02,1.42,-0.27,0.,0.,0.00654,0.,0.
0.,0.
*VISCOELASTIC,TIME=PRONY
0.25,,5.
0.25,,10.
*SOLID SECTION,MATERIAL=BIDERMAN,ELSET=ALLE
0.079, 
*STEP,NLGEOM,INC=100
*STATIC,STABILIZE,ALLSDTOL
.05,1.
*BOUNDARY
1601,1,,20.
*EL PRINT,ELSET=TOPE,FREQUENCY=1
S,E
*EL PRINT,ELSET=LEFTE,FREQUENCY=5
S,E
*NODE PRINT,NSET=ONE,FREQUENCY=1
U1,RF1
*NODE PRINT,NSET=LEFT,FREQUENCY=1
U2,RF1
*NODE PRINT,NSET=BOTTOM,FREQUENCY=1
U1,RF2
*NODE FILE,NSET=ONE,FREQUENCY=1
U,RF
*EL FILE,FREQUENCY=99
S,E
*ENERGY FILE
ALLSE
*END STEP
*STEP,NLGEOM,INC=120
*VISCO,CETOL=0.1
1.,100.
*BOUNDARY
1601,1,,20.
*EL PRINT,ELSET=TOPE,FREQUENCY=10
S,E
*EL PRINT,ELSET=LEFTE,FREQUENCY=10
S,E
*NODE PRINT,NSET=ONE,FREQUENCY=10
U1,RF1
*NODE PRINT,NSET=LEFT,FREQUENCY=10
U2,RF1
*NODE PRINT,NSET=BOTTOM,FREQUENCY=10
U1,RF2
*NODE FILE,NSET=ONE,FREQUENCY=10
U,RF
*EL FILE,FREQUENCY=20
S,E,CE
*ENERGY FILE,FREQUENCY=10
ALLSE
*END STEP