Assignment 5

COMPARING DIFFERENCE CONTACT INTERFACE LAWS IN RADIOSS

OBJECTIVES:

• To Create the mesh for bumper assembly, mesh size should be 6mm.
• We have to compare the contact interface laws by the following case.

1. Run the crash tube model as it is.
2. Change the Inacti=6 and run.
3. Create the type 11 contact and run.
4. Remove both notches and remove boundary condition on rigid body node then run.
5. Create a new notch in the middle, select the whole section and run.
6. Create a new notch with nodes only from opposing 2 faces and run.

PROCEDURE:

• We have to import the bumper model .hm files into the hypermesh.
• Then go to 2D – automesh – select the surface to mesh – elem size – elem type – automesh.
• Then go to 2D – connectors – seam – give spacing and tolerance – define the type of weld as spring to connect different component of the bumper via connectors.

CASE1:

• In this case we have to run the model as it’s without any change in radios.
• Import .0000 file into hypermesh.
• Then click analysis – radioss and locate the file location where it should be saved.
• Then plot contact energy, time step and internal energy.

The internal energy is constant after 26 ms.

The rigid wall force is max at 26.5ms and sudden drop in the force after that.

CASE2:

• In this case we have to change the contact interface type 7 inacti = 6.

• Open hypercrash by application – hypercrash and import the file into hypercrash.
• Then change the inacti value in type 7 contact interface and export it.
• Then Import .0000 file into hypermesh.
• Then click analysis – radioss and locate the file location where it should be saved.
• Then plot contact energy, time step and internal energy.

The rigid wall force is max at 26ms and sudden drop in the force after that.

CASE3:

• In this case we have to change the contact interface as type 11 and run.
• Open hypercrash by application – hypercrash and import the file into hypercrash.
• Then create new contact interface as type 11 in the browser the assign slave and master then export it.

• Then Import .0000 file into hypermesh.
• Then click analysis – radioss and locate the file location where it should be saved.
• Then plot contact energy, time step and internal energy.
• Both type 7 and type 11 are assigned due to that the run time will be more whene compare to other cases.

The internal energy is constant after 26 ms.

The rigid wall force is max at 26.16ms and sudden drop in the force after that.

CASE4:

• In this case we have to Remove both notches and remove boundary condition on rigid body node then run.

• Then Import .0000 file into hypermesh.
• Using geom – node edit – assign node we can assign the nodes and remove the notches.
• Then delete the boundary conditions in the solver browser.
• Then click analysis – radioss and locate the file location where it should be saved.
• Then plot contact energy, time step and internal energy.

The internal energy is constant after 26.8 ms.

The rigid wall force is max at 27.25ms and sudden drop in the force after that.

CASE5:

• In this case Create a new notch in the middle, select the whole section and run.

• Then Import .0000 file into hypermesh.
• Using geom – node edit – assign node we can assign the nodes and create the notch in the middle.
• Then delete the boundary conditions in the solver browser.
• Then click analysis – radioss and locate the file location where it should be saved.
• Then plot contact energy, time step and internal energy.

The internal energy is constant after 26.8 ms.

The rigid wall force is max at 27ms and sudden drop in the force after that.

CASE6:

• Create a new notch with nodes only from opposing 2 faces and run.

• Then Import .0000 file into hypermesh.
• Using geom – node edit – assign node we can assign the nodes and create the notch in the middle.
• Then delete the boundary conditions in the solver browser.
• Then click analysis – radioss and locate the file location where it should be saved.
• Then plot contact energy, time step and internal energy.

The internal energy is constant after 27.2 ms.

The rigid wall force is max at 27ms and sudden drop in the force after that.

CASE	MODIFICATION	NO.OF. CYCLE	ENERGY ERROR %	TIME (S)	CONTACT ENERGY KN	RIGID WALL ENERGY (J)
1	No modification	83600	-0.38% to -0.1	231.79 s	9.345e+01	1340
2	Inacti=6	83600	-0.46% to -0 %	234.32 s	9.345e+01	1340
3	Type 11	81800	-0.46% to -0 %	310.68 s	9.884e+01	1357
4	Remove notch & boundary conditions	76100	-0.36% to -0 %	274.66 s	8.094e+01	1128
5	Notch in middle	69900	-0.38% to -0 %	232.23 s	5.933e+01	1122.5
6	Notch in opp faces	79100	-0.37% to -0 %	267.48 s	1.525e+02	1250

RESULT AND CONCLUSION:

In this assignment learnt about the types of contact interface and how to assign them in RADIOSS and hupercrash.

https://drive.google.com/file/d/1uKvqt8EA5KHIobi7QwRcmf9Mu2_LW5Jh/view?usp=sharing