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
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