Hi,
I need some help.
I think there is a possible error in the Strain Energy density computation for Neo Hookean / Mooney Rivlin hyperelastic material models (probably extends to Polynomial too ).
Analytical solution= 0.525 MPa
Result = 0.79 MPa
Nominal stress and Strain curves agree with expected solution but not the final Strain Energy density.
This is an Hyperelastic model and strain energy density is a potential (I would expect solution only depends on final stretch lambda_u and C10 coefficient).
** Generated by Mecway 19.0
*NODE
1,0,0,0.1
2,0,0,0
3,1,0,0.1
4,1,0,0
5,0,-0.1,0.1
6,1,-0.1,0
7,0,-0.1,0
8,1,-0.1,0.1
*ELEMENT,TYPE=C3D8
1,6,8,3,4,7,5,1,2
*ELSET,ELSET=Hexahedral
1
*SURFACE,NAME=Moving_face
1,S1
*SURFACE,NAME=Base
1,S2
*MATERIAL,NAME=Neo_Hook
*HYPERELASTIC,NEO HOOKE
900000,2E-10
*MATERIAL,NAME=Mooney_Rivlin
*HYPERELASTIC,MOONEY-RIVLIN
900000,0,2E-10
*SOLID SECTION,ELSET=Hexahedral,MATERIAL=Mooney_Rivlin
*BOUNDARY
1,1,,0
1,2,,0
2,1,,0
2,2,,0
2,3,,0
3,2,,0
4,2,,0
4,3,,0
5,1,,0
6,3,,0
7,1,,0
7,3,,0
*AMPLITUDE,NAME=A_1
0,0
500,-0.5
*TIME POINTS,NAME=timepointsname
1
*STEP,NLGEOM=YES,INC=110,AMPLITUDE=STEP
*STATIC
5,500,0,5
*BOUNDARY,AMPLITUDE=A_1
3,1,,-1
*BOUNDARY,AMPLITUDE=A_1
4,1,,-1
*BOUNDARY,AMPLITUDE=A_1
6,1,,-1
*BOUNDARY,AMPLITUDE=A_1
8,1,,-1
*NODE FILE,GLOBAL=YES,TIME POINTS=timepointsname
U,RF
*EL FILE,TIME POINTS=timepointsname
S,NOE,ENER,E
*EL FILE
ENER
*EL PRINT, ELSET=Hexahedral
ENER
*END STEP
