Case 3 Case with elastic contact

 

The data files for the project are in directory: Cont_001\Exercises\Case 3\Data. Look for ! TODO  text in the datafile and follow the instructions.

 

In this tutorial exercise the tangential contact model will be set as elastic with no slip.  Taking Case2 datafile as starting point the Contact_property is modified as shown below. The displacement load 1 (lateral displacement) is activated back again and its magnitude is decreased to prevent model failure.

 

 

Contact_property

Data File

 

 

* Contact_property                  NUM=1

! ----------------------------------------

 Name                 "Block_friction"

 Compression_model      1                  

 Compression_properties IDM=1

  /"Normal Penalty"/             500

 Tangential_model       1                

 Tangential_properties IDM=1

  /"Tangential Penalty"/        1000          

 Adhesion_model         1

 Adhesion_properties   IDM=1

  /"Normal Penalty"/            1000

 

1The compression properties are left unchanged.

2Tangential model is set as elastic with no slip (model 1). Only tangential penalty stiffness property should be specified for this model

3The adhesion normal penalty stiffness is increased to 1000 MPa to prevent separation due to high shear.

 

 

 

 

Load data

Data File

 

 

* Global_loads               NUM=1

! ---------------------------------

 Prescribed_displacement IDM=3 JDM=1

  /Set1/   1 0 0

 Pres_displacement_geom_set   IDM=1

   "Top_Block"

 Pres_displacement_geom_ass   IDM=1

   1

 

 

* Time_curve_data                NUM=1

! ---------------------------------

 Time_curve                     IDM=3

   1.0  2.0   3.0

 Load_factor                    IDM=3

   0.0  0.2  -0.2

 

 

* Global_loads               NUM=2

! ---------------------------------

 Prescribed_displacement IDM=3 JDM=1

  /Set1/   0 0 1

 Pres_displacement_geom_set   IDM=1

   "Top_Block"

 Pres_displacement_geom_ass   IDM=1

   1

 

 

* Time_curve_data                NUM=2

! ---------------------------------

 Time_curve                     IDM=2

   0.0  1.0

 Load_factor                    IDM=2

   0.0  -0.05

 

 

* Load_case_control_data                

! ---------------------------------

 Loadcases                      IDM=2

  1  2

 Active_load_flags              IDM=2

  2  2

 

1The time curve for load 1 is modified in such a way that only 0.2 m of tangential (lateral) displacement is applied on the top surface of the top cube.

2Time curve for load case 2 is set to impose 0.05 m of downward displacement as in Case1.

3Both load cases 1 (lateral displacement) and 2 (downward compression) are set as active in Load_case_control_data.

 

 

 

Results

The result files for the project are in directory: Cont_001\Exercises\Case 3\Results.  Note how the elastic contact prevents slip and high shear and high stresses are generated.

 

Cont_001_Case3_Results

 

Glyph plot of contact stress vectors at the end of stage 3