# Contact Analysis (Part 1)

## Contact Analysis (Part 1)

This analysis uses the data of tutorial/09_contact_hertz.

### Analysis target

The analysis is a Hertz contact problem and the geometry to be analyzed is shown in Figure 4.9.1 and the mesh data is shown in Figure 4.9.2.

Item Description Notes Reference
Typo of analysis Non-linear static analysis(elastic,contact) !SOLUTION,TYPE=NLSTATIC !CONTACT
Number of nodes 408
Number of elements 168
Element type Eight node hexahedral element !ELEMENT,TYPE=361
Material name MAT1 !MATERIAL,NAME=MAT1
Material property ELASTIC !ELASTIC
Boundary conditions Restraint,Forced displacement
Matrix solution CG/SSOR !SOLVER,METHOD=CG,PRECOND=1

Fig. 4.9.1: Shape of the analysis target

Fig. 4.9.2: Mesh data of the analysis target

### Analysis content

The extended Lagrangian multiplier method is used to perform a contact analysis in which a forced displacement in the compressive direction is applied to the upper surface of a 1/4 disc model. The analytical control data are shown below.

#### Analysis control data cgs3.cnt.

#  Control File for FISTR
## Analysis Control
!VERSION
3
!SOLUTION, TYPE=NLSTATIC
!WRITE,RESULT
!WRITE,VISUAL
## Solver Control
### Boundary Conditon
!BOUNDARY, GRPID=1
ALL, 3, 3, 0.0
BOTTOM, 2, 2, 0.0
CENTER, 1, 1, 0.0
UPPER,  2, 2, -0.306
!CONTACT_ALGO, TYPE=ALAGRANGE
!CONTACT, GRPID=1
CP1, 0.0
### STEP
!STEP, SUBSTEPS=5, CONVERG=1.0e-5
BOUNDARY, 1
CONTACT,  1
### Material
!MATERIAL, NAME=MAT1
!ELASTIC
1100.0, 0.0
### Solver Setting
!SOLVER,METHOD=CG,PRECOND=1,ITERLOG=YES,TIMELOG=YES
1000, 1
1.0e-10, 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.

$cd FrontISTR/tutorial/09_contact_hertz$ fistr1 -t 4


### Analysis results

The results of the 5th substep are shown in Figure 4.9.3. A deformation diagram with contours of the y-direction displacement is created by REVOCAP_PrePost. A part of the analysis results log file is shown below as numerical data for the analysis results.

Fig. 4.9.3: Analysis results of deformation and y-direction displacement

#### 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