Analytical Rigid Contact Problems

[mmmbordo643]

I am simulating a compaction process with a die/punch assembly. It is 2d axisymmetric. The die wall and top and bottom punches are analytical rigid bodies. I have added reference nodes to the rigid bodies and have assigned all boundary conditions to thses nodes. I have also defined a friction penalty interaction between analytical surfaces (surface-surface contact, explicit) created under rigid body constraints. These interaction properties are between the die/punch and the elastic plastic material. When i run the explicit dynamic analysis, the elastic plastic material moves (actually moves through the rigid bodies) and the top and bottom punch (supposed to evenly compact from initial height of 10mm to final height of 3mm) do not move. Can anyone offer help?

Thanks,
Chris

 

[koetue]

Hello Chris,
have you checked the normal of the die surfaces? this is usualy the reason for moving through rigid bodies.

 

[Newuser2006]

Hallo koetue can you please explain more about the checking of the normals,since this is important for me also.

 

[koetue]

hello newuser2006,
the surface normal must show in the direction of the contact partner. If you're modelling in CAE you'll be able to chose the right surface of the rigid body during the surface definition. You can also import the input file in CAE and control the normals of the rigid body surface with TOOLS==>QUERY, but then I'm not so sure whether this works for 2D-rigid bodys. For the input file (and for CAE) you'll find a detailed description for diffrent types of analytical surfaces in "2.3.4 Defining analytical rigid surfaces" in the ABAQUS Analysis Users Manual.
koe