*HEADING
 TEST OF DEFORMATION GRADIENT, C3D8, TEST F23 ---
*RESTART,WRITE
*NODE,NSET=ALLN
*ELEMENT,TYPE=C3D8,ELSET=UHYP
*ELEMENT,TYPE=C3D8,ELSET=UMAT
*ELEMENT,TYPE=C3D8,ELSET=HYPE
*SOLID SECTION,ELSET=UHYP,MATERIAL=UHYP
*SOLID SECTION,ELSET=UMAT,MATERIAL=UMAT
*SOLID SECTION,ELSET=HYPE,MATERIAL=HYPE
*MATERIAL,NAME=UHYP
*HYPERELASTIC,USER,TYPE=COMPRESSIBLE
*MATERIAL,NAME=UMAT
*USER MATERIAL,CONSTANTS=3
*MATERIAL,NAME=HYPE
*HYPERELASTIC,N=1
80.,0.,2.013423E-4
*BOUNDARY
1,PINNED
2,PINNED
3,PINNED
4,PINNED
5,1
5,3
6,1
6,3
7,1
7,3
8,1
8,3
*STEP,NLGEOM
*STATIC,DIRECT
.1,1.
*BOUNDARY
5,2,,.1
6,2,,.1
7,2,,.1
8,2,,.1
*EL PRINT,FREQ=5
S,
DG,
*EL FILE,FREQ=5
S,DG
*NODE PRINT,FREQ=5
*END STEP