Seal analysis, problem with rigid body motion

[mizzjoey]

Hi everyone.

I'm trying to simulate an axisymmetric model of a brake seal being installed in a gland, and apply pressure afterwards. My problem is of rigid body motion. Occurs when I move the rigid surfaces to close in on the seal. To overcome this, I created a BC on the seal to hold it until the RSes at least touch the seal. In the next step when I resume installation the seal gets compressed as expected, but at 0.7 step time onwards the seal flies off to oblivion.

Can anyone explain what could be the reason for this? I have created the interactions as required.

thanks in advance,
jo

 

[gurmeet2003]

mizzjoey,

Can you apply a small initial displacement in the first step. This will establish initial contact and prevent rigid body motion latter. In the next step this artificial displacement can be removed.

Gurmeet

 

[mizzjoey]

Thank you Gurmeet for your suggestion.

An application of initial displacement was what I tried to achieve by creating a hold BC and releasing it in the next step. It seems that this did prevent the seal from flying about initially, but as the rigid surfaces are about to fully clamp on the seal, the seal goes off - which is really puzzling considering that it should be completely blocked by the RSes representing the caliper and the piston.

I'm currently trying to use *Contact interference, shrink to install the brake seal into the cavity. Can anyone please tell me in which level do I create this card in CAE? Or maybe someone could point me to the proper section in the documentation. Couldn't find the instructions in the manual.

thanks in advance,
jo