Non-linear Static Analysis (Elastoplastic, Part 1)

This analysis uses the data of tutorial/05_plastic_cylinder.

Analysis target

The object of analysis is the same round bar 1/8 model as in the Non-linear Static Analysis (Hyperelasticity, Part 1).

Item	Description	Remarks
Type of analysis	Non-linear static analysis (elastoplastic)	!SOLUTION,TYPE=NLSTATIC
Number of nodes	629
Number of elements	432
Element type	Eight node hexahedral element	!ELEMENT,TYPE=361
Material name	MAT1	!MATERICAL,NAME=MAT1
Material property	ELASTIC,PLASTIC	!ELASTIC !PLASTIC
Boundary condition	Restraint, Force displacement
Matrix solver	CG/SSOR	!SOLVER,METHOD=CG,PRECOND=1

Analysis content

The necking phenomenon of a round bar due to plastic deformation is analyzed. The Mises model is used for the yield function. The analytical control data is shown below.

Analysis control data `necking.cnt`

#  Control File for FISTR
## Analysis Control
!VERSION
 3
!SOLUTION, TYPE=NLSTATIC
!WRITE,RESULT,FREQUENCY=10
!WRITE,VISUAL,FREQUENCY=10
## 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=40, CONVERG=1.0e-3
 BOUNDARY, 1
### Material
!MATERIAL, NAME=MAT1
!ELASTIC
 206900.0, 0.29
!PLASTIC, YIELD=MISES, HARDEN=MULTILINEAR
 450.0, 0.0
 608.0, 0.05
 679.0, 0.1
 732.0, 0.2
 752.0, 0.3
 766.0, 0.4
 780.0, 0.5
### Output
!OUTPUT_VIS
 NSTRAIN, ON
!OUTPUT_RES
 ISTRESS, ON
### Solver Setting
!SOLVER,METHOD=CG,PRECOND=1,ITERLOG=NO,TIMELOG=YES
 2000, 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/05_plastic_cylinder
$ fistr1 -t 4
(Runs in 4 threads.)

Analysis results

The results of the 35th substep are shown in Figure 4.5.1. A deformation diagram with the Mises stress contours added is created by REVOCAP_PrePost. A part of the analysis results log file is shown below as numerical data for the analysis results.

Analysis results of deformation and Mises stress

Fig. 4.5.1: Analysis results of deformation and Mises stress

Analysis results 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

Non-linear Static Analysis (Elastoplastic, Part 1)