Compression of rubber seal

I am trying to compress a rubber seal in a cavity using a non-linear FEA. I set up three bodies, assigned contact to the relevant faces and tried to constrain the ‘fixed’ side and move the third part up to the rubber seal to simulate the crush using a fixed value table to set the start and end position.

Symmetry applied to try to stabilise the analysis.

Continues to crash as unstable.

Anyone care to take a look a see if you can resolve it?


Hi @gmorwood,

I took a quick look at your model and I have a few thoughts.

The sliding mate is typically for linear analysis only as it assumes small displacements. You might need to change this to a physical contact.

Your Rubber material is defined as linear elastic and it should probably be Hyperelastic.

I would remove the Symmetry boundary conditions until you get the model to working and I am not really sure they are needed in the first place. I would just constrain those faces to have no out of plane motion.

Finally, you displacement table has a displacement of 0 at T=0 and -1.39 METERS at T=1. I think you may have a unit mismatch here.

Let me know if any of these help or not. If not I will take a more detailed look at your model.

Good Luck,

1 Like

Hi @gmorwood,

I had a little time to take a look at your model. Check out this copy of your project.

I changed the time steps, contact definitions, and a few of the boundary conditions. Please take a look and let me know if you have any questions.

Take Care!


Wow, Thanks so much for your quick responses - I’ve got the hang of it now.