Interface error - why?

[rrakos]

Dear Simulate Users,

I often detect a problem when I use "contact" interfaces. The surfaces (under the interface) are in slippage with each other. The contact is OK for some timesteps but the surfaces start to overlap after a certain displacement. See the pictures:

In the last step, the full overlapping is one cell thickness which is very important in terms of the investigated process.

How can I avoid this error? (I think, the time step size and the mesh size is OK)

Thanks

Roland

[SweetPeasHub]

it seems to me like its the penalty formulation for contact is too soft initially so it doesn’t work correctly as the contact area and stiffness becomes much higher. I might try the config options to increase contact iterations and accuracy as well as decreasing the contact penetration depth config option. ( Creo 5 has changes making these options more up front and adds a penetration depth override for each interface feature.)I would give the correct configuration option names involved but am using my phone to respond and might not get on my Creo machine for a couple days.

I might also vary one side of the mesh with about half the element size of the other and then even flip which side is smaller. since the mesh sizes are so similar maybe it makes some trouble and I now see in your image that the part that works is less similar in mesh size like I am talking about

[skunks]

[rrakos]

I changed the mesh from fully structured hexa to unstructured hexa (like in your model). Based on results, the interface is ok, there is no overlapping. I think, my structured haxe mesh included too large size ratio between elements.