Contact and too big plastic deformation

[PoloQ]

Hello everybody,

I want to observe the plastic deformation after a contact between a ball and an other mechanical part.

You can see my model here:

http://imageshack.com/a/img837/379/kgl5.jpg

http://imageshack.com/a/img707/4646/eghb.jpg

I have results of experiences and I want to compare this results with the results of the simulation with Abaqus.

The problem is that these two results are really differents.

In the reality, if I press the ball on the part with 120kN, I have a CPRESS of 3600MPa and the plastic deformation after this press is 15µm.

With Abaqus, the CPRESS is no so bad, but the plastic deformation is very big: 230µm.

I think the problem is the definition of the normal contact in my model, but I can't find a configuration that gives me smaller plastic deformation.

Here is a little summary of my model:

-Elastic plastic material (I have strain-stress curve of it)
-Isotropic hardening
-frictionless tangential behaviour
-normal behaviour -> ? I try different configuration (penalty, lagrange) but it doesn't work

If you have an idea for my problem, it would be helpfull!

Thank you.

Polo.