Skip to content

Non-linear Static Analysis (Hyperelasticity, Part 2)

This analysis uses the data of tutorial/04_hyperelastic_spring.

Analysis target

The spring is the object of the analysis, the geometry is shown in Figure 4.4.1 and the mesh data is shown in Figure 4.4.2.

Item Description Notes Reference
Type of analysis Nonlinear static analysis (hyperelasticity) !SOLUTION,TYPE=NLSTATIC
Number of nodes 78,771
Number of elements 46,454
Element type Ten node tetrahedral quadratic element !ELEMENT,TYPE=342
Material name MAT1 !MATERIAL,NAME=MAT1
Material property HYPERELASTIC !HYPERELASTIC,TYPE=ARRUDA-BOYCE
Boundary conditions Restraint / prescribed displacement
Matrix solution CG/SSOR !SOLVER,METHOD=CG,PRECOND=1

Shape of the spring

Fig. 4.4.1: Shape of the spring

Mesh data of the spring

Fig. 4.4.2: Mesh data of the spring

Analysis content

A stress analysis is performed by constraining the displacement of the constrained surface shown in Figure 4.4.1 and applying a prescribed displacement to the prescribed-displacement surface. The Arruda-Boyce model is used for the hyperelastic material constitutive law. The analysis control data are shown below.

Analysis control data spring.cnt

#  Control File for FISTR
## Analysis Control
!VERSION
 3
!SOLUTION, TYPE=NLSTATIC
!WRITE,RESULT
!WRITE,VISUAL
## Solver Control
### Boundary Conditon
!BOUNDARY, GRPID=1
 LOADS, 2, 2, -5.0
 FIX,   1, 3, 0.0
### STEP
!STEP, SUBSTEPS=1, CONVERG=1.0e-5
 BOUNDARY, 1
### Material
!MATERIAL, NAME=MAT1
!HYPERELASTIC, TYPE=ARRUDA-BOYCE
 0.71, 1.7029, 0.1408
### 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 procedure

Execute the FrontISTR execution command fistr1.

cd FrontISTR/tutorial/04_hyperelastic_spring
fistr1 -t 4

(Runs in 4 threads.)

Analysis results

A deformation diagram with a contoured displacement is created by REVOCAP_PrePost and shown in Figure 4.4.3. A part of the log file is shown below as numerical data for the analysis results.

Analysis results of deformation and displacement

Fig. 4.4.3: Analysis results of deformation and displacement

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=     1
 ##### Local Summary @Node    :Max/IdMax/Min/IdMin####
 //U1    2.6070E-01     42179 -2.4651E-01     44163
 //U2    2.0567E-02     14512 -5.0036E+00     44753
 //U3    6.6559E-02     15443 -6.6862E-01     44664
 //E11   4.1026E-03      1015 -4.5809E-03      3429
 //E22   2.3030E-03     42626 -1.5152E-03     44761
 //E33   4.1949E-03     23553 -5.0169E-03     27938
 //E12   1.3348E-02     55149 -1.3381E-02     56829
 //E23   2.7881E-02     48353 -1.9534E-02     48322
 //E31   1.0861E-02     47938 -8.8803E-03      9493
 //S11   8.4247E-03      8264 -9.1017E-03      8501
 //S22   1.0769E-02     56772 -6.3921E-03     56787
 //S33   1.3881E-02     56764 -1.2778E-02     42632
 //S12   1.2396E-02     55149 -1.2434E-02     56829
 //S23   2.5880E-02     48353 -1.8138E-02     48322
 //S31   1.0081E-02     47938 -8.2435E-03      9493
 //SMS   4.9638E-02     48353  2.8482E-04     66578
 ##### Local Summary @Element :Max/IdMax/Min/IdMin####
 //E11   3.9156E-03     34074 -4.3403E-03     16932
 //E22   1.8391E-03     23282 -1.2721E-03     56220
 //E33   3.9490E-03     45925 -4.4530E-03     34145
 //E12   1.2578E-02     45680 -1.1729E-02     19492
 //E23   2.0534E-02     40739 -1.3512E-02     24172
 //E31   9.4162E-03     32786 -7.6149E-03     44971
 //S11   7.7882E-03     25880 -8.2932E-03     45925
 //S22   6.8884E-03     23275 -6.1373E-03     49821
 //S33   9.9242E-03     59974 -9.5475E-03     31626
 //S12   1.1679E-02     45680 -1.0893E-02     19492
 //S23   1.9071E-02     40739 -1.2534E-02     24172
 //S31   8.7376E-03     32786 -7.0660E-03     44971
 //SMS   3.5586E-02     40739  4.1161E-04     40537
 ##### Global Summary @Node    :Max/IdMax/Min/IdMin####
 //U1    2.6070E-01     42179 -2.4651E-01     44163
 //U2    2.0567E-02     14512 -5.0036E+00     44753
 //U3    6.6559E-02     15443 -6.6862E-01     44664
 //E11   4.1026E-03      1015 -4.5809E-03      3429
 //E22   2.3030E-03     42626 -1.5152E-03     44761
 //E33   4.1949E-03     23553 -5.0169E-03     27938
 //E12   1.3348E-02     55149 -1.3381E-02     56829
 //E23   2.7881E-02     48353 -1.9534E-02     48322
 //E31   1.0861E-02     47938 -8.8803E-03      9493
 //S11   8.4247E-03      8264 -9.1017E-03      8501
 //S22   1.0769E-02     56772 -6.3921E-03     56787
 //S33   1.3881E-02     56764 -1.2778E-02     42632
 //S12   1.2396E-02     55149 -1.2434E-02     56829
 //S23   2.5880E-02     48353 -1.8138E-02     48322
 //S31   1.0081E-02     47938 -8.2435E-03      9493
 //SMS   4.9638E-02     48353  2.8482E-04     66578
 ##### Global Summary @Element :Max/IdMax/Min/IdMin####
 //E11   3.9156E-03     34074 -4.3403E-03     16932
 //E22   1.8391E-03     23282 -1.2721E-03     56220
 //E33   3.9490E-03     45925 -4.4530E-03     34145
 //E12   1.2578E-02     45680 -1.1729E-02     19492
 //E23   2.0534E-02     40739 -1.3512E-02     24172
 //E31   9.4162E-03     32786 -7.6149E-03     44971
 //S11   7.7882E-03     25880 -8.2932E-03     45925
 //S22   6.8884E-03     23275 -6.1373E-03     49821
 //S33   9.9242E-03     59974 -9.5475E-03     31626
 //S12   1.1679E-02     45680 -1.0893E-02     19492
 //S23   1.9071E-02     40739 -1.2534E-02     24172
 //S31   8.7376E-03     32786 -7.0660E-03     44971
 //SMS   3.5586E-02     40739  4.1161E-04     40537