Non-Linear Static Analysis (Hyperelasticity, Part 1)
Non-Linear Static Analysis (Hyperelasticity, Part 1)
This analysis uses the data of tutorial/03_hyperelastic_cylinder.
Analysis target
The analysis target is a 1/8th model of a round bar. The geometry is shown in Figure 4.3.1 and the mesh data is shown in Figure 4.3.2.
| Item | Description | Remarks | Reference |
|---|---|---|---|
| Type of analysis | Non-linear static analysis (hyperelasticity) | !SOLUTION,TYPE=NLSTATIC | |
| Number of nodes | 629 | ||
| Number of elements | 432 | ||
| Element type | Eight node hexahedral element | !ELEMENT,TYPE=361 | |
| Material name | MAT1 | !MATERIAL,NAME=MAT1 | |
| Material property | ELASTIC | !ELASTIC | |
| Boundary condition | Restraint, Forced displacement | ||
| Matrix solver | CG/SSOR | !SOLVER,METHOD=CG,PRECOND=1 |
Fig. 4.3.1 : Shape of the round bar (1/8 model)
Fig. 4.3.2: Shape of the round bar (1/8 model)
Analysis content
In this stress analysis, an axial tensile displacement is given to a round bar. The Mooney–Rivlin model was used in the material constitutive equation of hyperelasticity. The analysis control data are presented 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
The results of the fifth substep are shown in Figure 4.3.3. A deformation diagram with Mises stress contours is created by REVOCAP_PrePost. A part of the analysis results log file is shown below as numerical data for the analysis results.
Fig. 4.3.3: Analysis results of deformation and Mises stress
Log file 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