*HEADING - OGDEN HYPERELASTICITY, UNIAXIAL TENSION 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=C3D8RH,ELSET=ONE 1,1,2,3,4,5,6,7,8 *SOLID SECTION,ELSET=ONE,MATERIAL=MOONEY *MATERIAL,NAME=MOONEY *HYPERELASTIC,OGDEN,N=2 160.,2.,40.,-2. *STEP,PERTURBATION Initial static linear perturbation, uniaxial tension *STATIC *LOAD CASE,name = "uniaxial tension 1" *BOUNDARY FACE1,3 FACE3,2 FACE6,1 FACE4,1,1,.1 *END LOAD CASE *LOAD CASE,name = "uniaxial tension 2" *BOUNDARY FACE1,3 FACE3,2 FACE6,1 FACE4,1,1,.2 *END LOAD CASE *LOAD CASE,name = "uniaxial tension 3" *BOUNDARY FACE1,3 FACE3,2 FACE6,1 FACE4,1,1,.3 *END LOAD CASE *OUTPUT,FIELD,VARIABLE=PRESELECT *END STEP *STEP,NLGEOM,INC=20 Step 2: Uniaxial tension, stretch=3.5 *STATIC,DIRECT 1.,10. *BOUNDARY FACE1,3 FACE3,2 FACE6,1 FACE4,1,1,2.5 *EL PRINT,F=100 *NODE PRINT,F=100 *END STEP *STEP,PERTURBATION Step 3: Static linear perturbation, uniaxial tension *STATIC *BOUNDARY FACE1,3 FACE3,2 FACE6,1 FACE4,1,1,.1 *OUTPUT,FIELD *ELEMENT OUTPUT S,E ENER, *OUTPUT,FIELD *NODE OUTPUT U,RF *END STEP *STEP,NLGEOM,INC=20 Step 4: Uniaxial tension, stretch=6. *STATIC,DIRECT 1.,10. *BOUNDARY FACE4,1,1,5. *END STEP *STEP,PERTURBATION Step 5: Static perturbation, uniaxial tension *STATIC *BOUNDARY FACE1,3 FACE3,2 FACE6,1 FACE4,1,1,.1 *OUTPUT,FIELD *ELEMENT OUTPUT S,E ENER, *OUTPUT,FIELD *NODE OUTPUT U,RF *END STEP