Nonlinear Static Analysis (Hyperelasticity, Part 1)¶
This analysis uses the data in tutorial/03_hyperelastic_cylinder.
Analysis Model¶
The analysis model is a one-eighth model of a round bar. Its geometry is shown in Figure 4.3.1, and its mesh data are shown in Figure 4.3.2.
| Item | Description | Remarks | Reference |
|---|---|---|---|
| Analysis type | Nonlinear static analysis (hyperelasticity) | !SOLUTION,TYPE=NLSTATIC | |
| Number of nodes | 629 | ||
| Number of elements | 432 | ||
| Element type | 8-node linear hexahedral element | !ELEMENT,TYPE=361 | |
| Material name | MAT1 | !MATERIAL,NAME=MAT1 | |
| Material property | HYPERELASTIC | !HYPERELASTIC,TYPE=MOONEY-RIVLIN | |
| Boundary conditions | Constraints, prescribed displacement | ||
| Matrix solver | CG/SSOR | !SOLVER,METHOD=CG,PRECOND=1 |
Figure 4.3.1 Geometry of the round bar (1/8 model)
Figure 4.3.2 Mesh data for the round bar (1/8 model)
Analysis Description¶
A stress analysis is performed by applying an axial tensile displacement to the round bar. The Mooney-Rivlin model is used as the constitutive model for the hyperelastic material. The analysis control data are shown below.
Analysis Control Data cylinder.cnt¶
# Control File for FISTR
## Analysis Control
!VERSION
3
!SOLUTION, TYPE=NLSTATIC
!WRITE,RESULT
!WRITE,VISUAL
## Solver Control
### Boundary Conditon
!BOUNDARY, GRPID=1
LOADS, 3, 3, -7.0
FIX, 3, 3, 0.0
XSYMM, 1, 1, 0.0
YSYMM, 2, 2, 0.0
### STEP
!STEP, SUBSTEPS=5, CONVERG=1.0e-5
BOUNDARY, 1
### Material
!MATERIAL, NAME=MAT1
!HYPERELASTIC, TYPE=MOONEY-RIVLIN
0.1486, 0.4849, 0.0789
### Solver Setting
!SOLVER,METHOD=CG,PRECOND=1,ITERLOG=YES,TIMELOG=YES
10000, 1
1.0e-8, 1.0, 0.0
## Post Control
!VISUAL,metod=PSR
!surface_num=1
!surface 1
!output_type=VTK
!END
Analysis Results¶
For the results at the fifth substep, Figure 4.3.3 shows a deformed-shape plot with Mises stress contours created using REVOCAP_PrePost. As numerical data for the analysis results, an excerpt from the analysis result log file is also shown below.
Figure 4.3.3 Analysis results for deformation and Mises stress
Analysis Result Log 0.log¶
fstr_setup: OK
#### Result step= 0
##### Local Summary @Node :Max/IdMax/Min/IdMin####
//U1 0.0000E+00 1 0.0000E+00 1
//U2 0.0000E+00 1 0.0000E+00 1
//U3 0.0000E+00 1 0.0000E+00 1
//E11 0.0000E+00 1 0.0000E+00 1
//E22 0.0000E+00 1 0.0000E+00 1
//E33 0.0000E+00 1 0.0000E+00 1
//E12 0.0000E+00 1 0.0000E+00 1
//E23 0.0000E+00 1 0.0000E+00 1
//E31 0.0000E+00 1 0.0000E+00 1
//S11 0.0000E+00 1 0.0000E+00 1
//S22 0.0000E+00 1 0.0000E+00 1
//S33 0.0000E+00 1 0.0000E+00 1
//S12 0.0000E+00 1 0.0000E+00 1
//S23 0.0000E+00 1 0.0000E+00 1
//S31 0.0000E+00 1 0.0000E+00 1
//SMS 0.0000E+00 1 0.0000E+00 1
##### Local Summary @Element :Max/IdMax/Min/IdMin####
//E11 0.0000E+00 1 0.0000E+00 1
//E22 0.0000E+00 1 0.0000E+00 1
//E33 0.0000E+00 1 0.0000E+00 1
//E12 0.0000E+00 1 0.0000E+00 1
//E23 0.0000E+00 1 0.0000E+00 1
//E31 0.0000E+00 1 0.0000E+00 1
//S11 0.0000E+00 1 0.0000E+00 1
//S22 0.0000E+00 1 0.0000E+00 1
//S33 0.0000E+00 1 0.0000E+00 1
//S12 0.0000E+00 1 0.0000E+00 1
//S23 0.0000E+00 1 0.0000E+00 1
//S31 0.0000E+00 1 0.0000E+00 1
//SMS 0.0000E+00 1 0.0000E+00 1
##### Global Summary @Node :Max/IdMax/Min/IdMin####
//U1 0.0000E+00 1 0.0000E+00 1
//U2 0.0000E+00 1 0.0000E+00 1
//U3 0.0000E+00 1 0.0000E+00 1
//E11 0.0000E+00 1 0.0000E+00 1
//E22 0.0000E+00 1 0.0000E+00 1
//E33 0.0000E+00 1 0.0000E+00 1
//E12 0.0000E+00 1 0.0000E+00 1
//E23 0.0000E+00 1 0.0000E+00 1
//E31 0.0000E+00 1 0.0000E+00 1
//S11 0.0000E+00 1 0.0000E+00 1
//S22 0.0000E+00 1 0.0000E+00 1
//S33 0.0000E+00 1 0.0000E+00 1
//S12 0.0000E+00 1 0.0000E+00 1
//S23 0.0000E+00 1 0.0000E+00 1
//S31 0.0000E+00 1 0.0000E+00 1
//SMS 0.0000E+00 1 0.0000E+00 1
##### Global Summary @Element :Max/IdMax/Min/IdMin####
//E11 0.0000E+00 1 0.0000E+00 1
//E22 0.0000E+00 1 0.0000E+00 1
//E33 0.0000E+00 1 0.0000E+00 1
//E12 0.0000E+00 1 0.0000E+00 1
//E23 0.0000E+00 1 0.0000E+00 1
//E31 0.0000E+00 1 0.0000E+00 1
//S11 0.0000E+00 1 0.0000E+00 1
//S22 0.0000E+00 1 0.0000E+00 1
//S33 0.0000E+00 1 0.0000E+00 1
//S12 0.0000E+00 1 0.0000E+00 1
//S23 0.0000E+00 1 0.0000E+00 1
//S31 0.0000E+00 1 0.0000E+00 1
//SMS 0.0000E+00 1 0.0000E+00 1
...
#### Result step= 5
##### Local Summary @Node :Max/IdMax/Min/IdMin####
//U1 0.0000E+00 1 -6.7543E-01 90
//U2 0.0000E+00 1 -6.7543E-01 89
//U3 0.0000E+00 1 -7.0000E+00 38
//E11 -1.0781E-01 38 -1.1448E-01 7
//E22 -1.0781E-01 50 -1.1448E-01 13
//E33 2.3916E-01 7 2.2715E-01 50
//E12 8.9609E-04 53 -9.2501E-04 10
//E23 1.0074E-07 38 -2.6232E-03 86
//E31 1.0074E-07 50 -2.6232E-03 93
//S11 2.7292E-03 14 -2.6468E-03 49
//S22 2.7292E-03 6 -2.6468E-03 39
//S33 8.5422E-01 7 8.1021E-01 50
//S12 1.2861E-03 53 -1.3373E-03 10
//S23 1.4289E-07 38 -3.1695E-03 86
//S31 1.4289E-07 50 -3.1695E-03 93
//SMS 8.5307E-01 7 8.1134E-01 50
##### Local Summary @Element :Max/IdMax/Min/IdMin####
//E11 -1.0817E-01 759 -1.1410E-01 354
//E22 -1.0817E-01 768 -1.1410E-01 363
//E33 2.3863E-01 354 2.2766E-01 759
//E12 7.4078E-04 766 -7.5734E-04 360
//E23 -2.5376E-05 753 -2.4790E-03 471
//E31 -2.5376E-05 749 -2.4790E-03 462
//S11 2.8994E-03 363 -2.8080E-03 768
//S22 2.8994E-03 354 -2.8080E-03 759
//S33 8.5295E-01 354 8.1143E-01 759
//S12 1.0634E-03 766 -1.0947E-03 360
//S23 -3.0682E-05 753 -2.9954E-03 471
//S31 -3.0682E-05 749 -2.9954E-03 462
//SMS 8.5118E-01 354 8.1315E-01 759
##### Global Summary @Node :Max/IdMax/Min/IdMin####
//U1 0.0000E+00 1 -6.7543E-01 90
//U2 0.0000E+00 1 -6.7543E-01 89
//U3 0.0000E+00 1 -7.0000E+00 38
//E11 -1.0781E-01 38 -1.1448E-01 7
//E22 -1.0781E-01 50 -1.1448E-01 13
//E33 2.3916E-01 7 2.2715E-01 50
//E12 8.9609E-04 53 -9.2501E-04 10
//E23 1.0074E-07 38 -2.6232E-03 86
//E31 1.0074E-07 50 -2.6232E-03 93
//S11 2.7292E-03 14 -2.6468E-03 49
//S22 2.7292E-03 6 -2.6468E-03 39
//S33 8.5422E-01 7 8.1021E-01 50
//S12 1.2861E-03 53 -1.3373E-03 10
//S23 1.4289E-07 38 -3.1695E-03 86
//S31 1.4289E-07 50 -3.1695E-03 93
//SMS 8.5307E-01 7 8.1134E-01 50
##### Global Summary @Element :Max/IdMax/Min/IdMin####
//E11 -1.0817E-01 759 -1.1410E-01 354
//E22 -1.0817E-01 768 -1.1410E-01 363
//E33 2.3863E-01 354 2.2766E-01 759
//E12 7.4078E-04 766 -7.5734E-04 360
//E23 -2.5376E-05 753 -2.4790E-03 471
//E31 -2.5376E-05 749 -2.4790E-03 462
//S11 2.8994E-03 363 -2.8080E-03 768
//S22 2.8994E-03 354 -2.8080E-03 759
//S33 8.5295E-01 354 8.1143E-01 759
//S12 1.0634E-03 766 -1.0947E-03 360
//S23 -3.0682E-05 753 -2.9954E-03 471
//S31 -3.0682E-05 749 -2.9954E-03 462
//SMS 8.5118E-01 354 8.1315E-01 759