Learning Forum

[bauer]

Hello everyone,

I’m currently looking into ways one could implement a contact stiffness that depends on the local contact pressure. Ideally this would be part of the contact formulation itself, but I’d also be open to approaches where this is handled through the material model or some kind of user‑defined behaviour.

Let’s assume we already know a function for the stiffness, for example k(p) = b · p, with b being some factor obtained beforehand. It could also be nonlinear, that’s not the main point.

I think this could be quite interesting for certain contact problems where the pressure distribution is computed anyway, and where small additional deformations have a noticeable influence on the macroscopic stress state of the parts in contact. At the same time, one wouldn’t need to explicitly model the microscopic behaviour that actually governs the real contact stiffness, since that part could be calculated separately and then condensed into such an effective stiffness law.

Does anyone know if there are ways to implement something like this? My experience with such custom implementations in ANSYS Workbench, MAPDL or pyMAPDL is still pretty limited, so any hints or examples would be greatly appreciated.

Many thanks!

[ErKo]

 

 

 

 

Hi

See this example that shows similar (you just need to change the *DIM to be PRESSURE not GAP, and rmodif,cid,3 for FKN contact stiffn. instead of the examples rmodif,cid,14 for TCC – see help manual for real constants)

Thermal Contact Conductance (TCC) & Element Gaps | Ansys WB

3.9. Set the Real Constants and Element KEYOPTS


All the best

Erko