*HEADING
PRESSURIZING OF A FLAT RUBBER PLATE (CAX6H) - OGDEN HYPERELASTICITY   
WITH UNIFORM PRESTRESS (RADIAL AND CIRCUMFERENTIAL)
*NODE
1,0.,0.,0.
11,7.5,0.0,0.0
21,0.0,.25,0.0
31,7.5,.25,0.0
41,0.0,.50,0.0
51,7.5,.50,0.0
*NGEN,LINE=P
1,11,1,,2.142857143
21,31,1,,2.142857143,.25
41,51,1,,2.142857143,.50,.0
*NSET,NSET=CENTER
1,21,41
*ELEMENT,TYPE=CAX6H,ELSET=ONE
1,1,3,43,2,23,22
2,1,43,41,22,42,21
*ELGEN,ELSET=ALL
1,5,2,2
2,5,2,2
*ELSET,ELSET=BOT,GENERATE
1,9,2
*BOUNDARY
31,1,2
CENTER,XSYMM
*EQUATION
2, 
51,1,1.0,11,1,1.0
2, 
51,2,1.0,11,2,1.0
*ELSET,ELSET=ONE
1, 
*SOLID SECTION,MATERIAL=A1,ELSET=ALL
*MATERIAL,NAME=A1
*HYPERELASTIC,OGDEN,N=2
160.,2.,40.,-2.
*INITIAL CONDITIONS,TYPE=STRESS
ALL, 50.,0.,50.
*RESTART,WRITE,FREQUENCY=2
*STEP,NLGEOM, UNSYMM=YES
 MAINTAIN PRESTRESS - THIS STEP IS FOR VERIFICATION PURPOSES OF INITIAL
 STRESSES IN HYPERELASTICITY
*STATIC
*BOUNDARY
CENTER,XSYMM
31,1,2
*EL PRINT,FREQUENCY=5,ELSET=ALL
COORD , E
DG, 
LOADS, 
S,MISES
ENER, 
*EL PRINT,FREQUENCY=1,ELSET=ONE,SUMMARY=NO
COORD , E
DG, 
LOADS, 
S,MISES
ENER, 
*NODE FILE,NSET=CENTER
U ,RF
*OUTPUT,FIELD
*NODE OUTPUT,NSET=CENTER
U,RF
*EL FILE,FREQUENCY=2,ELSET=ONE
S, 
LOADS, 
*OUTPUT,FIELD,FREQ=2
*ELEMENT OUTPUT,ELSET=ONE
S,
LOADS,
*NODE PRINT
U,RF
*END STEP
*STEP,NLGEOM,INC=12, UNSYMM=YES
 APPLY PRESSURE TO RUBBER PLATE
*STATIC,RIKS
.01,1.0,.00001,1.0,1.0,1,1,10000.
CENTER,XSYMM
*DLOAD
ALL,P1,2.E+2
*MONITOR,NODE=21,DOF=2
*END STEP