*HEADING
  - INCOMPRESSIBLE HYPERELASTICITY (YEOH), BIAXIAL TENSION
*NODE,NSET=ALL
1,
2,1.
3,1.,1.,
4,0.,1.,
*ELEMENT,TYPE=CPS4R,ELSET=ONE
1,1,2,3,4
*NSET,NSET=SIDE1
1,2
*NSET,NSET=SIDE2
2,3
*NSET,NSET=SIDE3
3,4
*NSET,NSET=SIDE4
4,1
*SOLID SECTION,ELSET=ONE,MATERIAL=YEOH
*MATERIAL,NAME=YEOH
*HYPERELASTIC, YEOH
100., -1., 0.01
*STEP,NLGEOM,INC=20
BIAXIAL TENSION
*STATIC,DIRECT
1.,20.
*BOUNDARY,OP=NEW
SIDE4,1
SIDE1,2
SIDE2,1,1,5.
SIDE3,2,2,5.
*EL PRINT,F=10
S, 
E, 
*NODE PRINT,F=10
U,RF
*EL FILE,F=10
S,E
*NODE FILE,F=10
U,RF
*END STEP