Brake disc coupled temp-disp help?

[Tom690]

Hi all! I’m trying to model a rigid brake disc with a rigid pad applied. I have made a version with a simple disc and symmetry so only one pad is applied which works (although it takes a very long time due to warning: ‘displacement increment is too big’ if anyone can advice how to precent this?). However, when i change the geometry to be a full disc model and add a second pad i get the ‘too many attempts’ error. I have the parts modelled as deformable, with rigid body constraints applied linking them each to a RP. I have then got a BC on the pad RPs to limit all by y displacement, and a BC on the disc RP limiting all but the correct rotation. These are active in the initial step. The i have a coupled temp-disp step where the pad force is applied (on their RPs) and a BC for the disc rotation (also on its RP). Can anyone please help me make this run? I’m very confused since the simple version is set up the same way and works. Thanks!

 

[FEA way]

To avoid rigid body motions, you can replace the force on the pad with prescribed displacement. Or enable automatic/contact stabilization.

 

[Tom690]

Hi FEA Way, thanks for the reply! Unfortunately the force on the pad is something i need to set a value for so i don’t think I’d be able to change it for a displacement. Could you please explain what you mean about automatic/ contact stabilisation and how it can help? Thanks again!

 

[FEA way]

You could measure it as a reaction force when displacement is prescribed and figure out the right magnitude of the displacement to achieve the expected force.

Automatic stabilization is enabled in step settings, contact stabilization is a separate feature for contact pairs or general contact. They add some numerical damping to help with initial rigid body motions before contact is established.