Initiating contact by applying force to rigid body

[rm447]

Hi,

I am modeling creep indentation of a material with a rigid flat punch modeled as a rigid analytical surface, and the analysis doesn't converge if I apply the load right away (as also discussed in thread799-293302). Instead I tried displacing the indenter by a small amount (step 1) to bring the two bodies in contact and then apply the force (step 2) by ramping it up to a maximum value and then keep it constant, but the problem is maintaining the correct displacement boundary conditions and forces simultaneously. The problem is the following:

In step one, I apply the small displacement by defining a displacement BC.If I remove this BC in the second step, that just ramps the displacement back to zero over the length of the step, and wouldn't let me see any displacement due to creep under the applied force. If I don't remove it, then it will just keep the value it had in the previous step.

I don't know how to get around this issue! Any ideas?

Thanks,
Kacy

 

[portliner]

You may continue the loading by specifying the displacement only. Displace the rigid surface until you reach the desired force, can be plotted as reaction force on the reference point "RF1" if in the x-direction