Is Transient Structural Analysis Necessary for Contact Problems in ANSYS 12?

[albipittino]

Hello all!
I'm modeling with ANSYS 12 (workbench) an assembly made up by components which are initially in "gap" condition, going in contact after deformation due to the applied pressure load. I tried in a "static structural" analysis by settings the manual contact regions type "frictionless" and interface treatment "add offset, ramped effect, 0 mm" or even "adjust to touch", but these modeling are both not realistic.
Anyone knows if it is mandatory a "transient structural analysis" for these contacts, or may I use a "static structural analysis" with other settings for contacts? Consider that the material I use are non linear.
Thanks all.

 

[Mech_Engineer]

Hello all!
I'm modeling with ANSYS 12 (workbench) an assembly made up by components which are initially in "gap" condition, going in contact after deformation due to the applied pressure load. I tried in a "static structural" analysis by settings the manual contact regions type "frictionless" and interface treatment "add offset, ramped effect, 0 mm" or even "adjust to touch", but these modeling are both not realistic.
Anyone knows if it is mandatory a "transient structural analysis" for these contacts, or may I use a "static structural analysis" with other settings for contacts? Consider that the material I use are non linear.
Thanks all.

You're setting the problem up incorrectly. You have to define a contact region beteween the two surfaces that will touch, define a "pinball region" length which is smaller than the initial gap, and then use ANSYS's nonlinear solver with sub-steps. It's all pretty straightforward to do in ANSYS Workbench.

Take a look at this thread: https://www.physicsforums.com/showthread.php?t=433240&highlight=ansys+contact

 

[albipittino]

First of all thanks for answering.
Ok. I have done what you suggest:
- non linear analysis (material and transient model);
- many substeps;
- pinball region adequate to gap.

Still no convergence is reached.
I have noticed that the problem is that one component is subject to a rigid motion before contacts with the other.
Avoiding rigid motion (just inserting a zero displacement restraint on one side of the body),
the cvonvergence is reached.
Stay tuned for updates of these problems, thanks!