*HEADING
  - HYPERFOAM, UNIAXIAL COMPRESSION WITH LINEAR PERTURBATION STEPS
*NODE,NSET=ALL
1,
2,1.
3,1.,1.,
4,0.,1.,
5,0.,0.,1.
6,1.,0.,1.
7,1.,1.,1.
8,0.,1.,1.
*NSET,NSET=FACE1
1,2,3,4
*NSET,NSET=FACE2
5,6,7,8
*NSET,NSET=FACE3
1,2,5,6
*NSET,NSET=FACE4
2,3,6,7
*NSET,NSET=FACE5
3,4,7,8
*NSET,NSET=FACE6
4,1,8,5
*ELEMENT,TYPE=C3D8R,ELSET=ONE
1,1,2,3,4,5,6,7,8
*SOLID SECTION,ELSET=ONE,MATERIAL=FOAM
*MATERIAL,NAME=FOAM
** FROM TEST DATA OF MHFTDO3EUC
*HYPERFOAM,N=2
0.167099,9.00665, 2.153721E-5,-4.86940
*STEP,PERTURBATION
Step 1: Initial MULTIPLE LOAD CASE, uniaxial compression
*STATIC
*LOAD CASE,name= "uniaxial compression 1"
*BOUNDARY
FACE1,3
FACE3,2
FACE6,1
FACE4,1,1,-0.10
*END LOAD CASE
*LOAD CASE,name= "uniaxial compression 2"
*BOUNDARY
FACE1,3
FACE3,2
FACE6,1
FACE4,1,1,-0.20
*END LOAD CASE
*OUTPUT,FIELD
*ELEMENT OUTPUT
S,E
*OUTPUT,FIELD
*NODE OUTPUT
U,RF
*END STEP
*STEP,NLGEOM,INC=20
Step 2: Uniaxial compression, stretch=0.6
*STATIC,DIRECT
1.,10.
*BOUNDARY
FACE1,3
FACE3,2
FACE6,1
FACE4,1,1,-0.40
*EL PRINT,F=100
*NODE PRINT,F=100
*OUTPUT,FIELD,FREQ=100
*ELEMENT OUTPUT
S,E
*OUTPUT,FIELD,FREQ=100
*NODE OUTPUT
U,RF
*END STEP
*STEP,PERTURBATION
Step 3: LOAD CASE, uniaxial compression
*STATIC
*LOAD CASE,name="uniaxial compression 3"
*BOUNDARY
FACE1,3
FACE3,2
FACE6,1
FACE4,1,1,-0.10
*END LOAD CASE
*LOAD CASE,name="uniaxial compression 4"
*BOUNDARY
FACE1,3
FACE3,2
FACE6,1
FACE4,1,1,-0.20
*END LOAD CASE
*OUTPUT,FIELD
*ELEMENT OUTPUT
S,E
*OUTPUT,FIELD
*NODE OUTPUT
U,RF
*END STEP
*STEP,NLGEOM,INC=20
Step 4: Uniaxial compression, stretch=0.2
*STATIC,DIRECT
1.,10.
*BOUNDARY
FACE1,3
FACE3,2
FACE6,1
FACE4,1,1,-0.80
*END STEP
*STEP,PERTURBATION
Step 5: Load case, uniaxial compression
*STATIC
*LOAD CASE,name="uniaxial compression 5"
*BOUNDARY
FACE1,3
FACE3,2
FACE6,1
FACE4,1,1,-0.10
*END LOAD CASE 
*LOAD CASE,name="uniaxial compression 6"
*BOUNDARY
FACE1,3
FACE3,2
FACE6,1
FACE4,1,1,-0.20
*END LOAD CASE 
*OUTPUT,FIELD
*ELEMENT OUTPUT
S,E
*OUTPUT,FIELD
*NODE OUTPUT
U,RF
*END STEP