Assignment 5-RADIOSS Interfaces & Study of Effect of Notches Challenge

AIM

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• Create the mesh on the Bumper model
• Run the crash tube model as the instruction.
  • Run the crash tube model as it is.
  • Change the inacti =6 and then run.
  • Create the Type 11 contact and then run.
  • Remove both the notches and boundary conditions of rigid body node and run.
  • Create the notches on the middle of model and then run.
  • Create the nodes on the middle of model but only in 2 opposite faces and then run.

OBJECTIVE

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• Get knowledge about different type of contact definition in Radioss.
• Get knowledge about parameters of defining contacts.

THEORY

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Contact modeling/ Interface modeling refers to the behavior of two different models when they come into contact with each other.

Different types of contacts are in table below:

Sl no	Interface Type	Description	Purpose
1	Type 7	General node to surface	Crash structure applications
2	Type 11	Edge to Edge	Crash structure applications
3	Type 24	General node and surface to surface	Crash structure applications

Parameters:

• I_gap: Determines how the size of the gap is calculated.
• Gap_min: Minimum gap for activation of interface.
• Inacti: Action to take if initial penetration exist.
• I_stf: Affects how the stiffness of interface is calculated.
• I_form: Frictional formulation.
• St_min: Minimum stiffness to use in the interface.
• I_del: What to do with the slave nodes and master segments if element fails.

PROCEDURE

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Meshing of Bumper model

1. Crash tube model run

Analysis < Radioss < Radioss

2. Change inacti =6

For changing the inacti

Solver Browser < INTER < TYPE 7 < Self contact < inacti =6

After altering inacti run again

3. Create TYPE 11

Open the previous model and create the TYPE 11 contact.

Right click on solver browser < Create < INTER < Type 11

After creating components are selected

Solver < INTER < TYPE 11 < New Inter3 < Line_id(S) < Component < Select all

Solver < INTER < TYPE 11 < New Inter3 < Line_id(M) < Component < Select all

Here the both the surfaces are same because contact is defined as self contact.

Parameters are filled as followed

4. Remove the notches and boundary conditions

For removing the notches Align nodes are used

Geometry < Nodes edit < Align node

Final model looks like

Now boundary condition is removed .To remove the boundary condition simply delete the BCS card.

Now the analysis is done

5. Notches at the middle of model

Again the notches are formed at the middle of model and model was run again.

6. Notches at the opposite side of model in middle

Here also notches are created by the align node method in opposite side.

CONCLUSION

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Sl no	Description	Plot
1	Type 7 basic
2	Type 11
3	Type 7 Inacti=6
4	No notches and boundary conditions
5	Notches at middle
6	Opposite notches

From the above plot it is evident that for Type 11 contact energy is maximum and when boundary condition and notches are removed it is minimum.