Hi, thanks for your answer.

Yes, the model converge with linear material properties.
The plastic strain is high, but somewhat localized. I show you the regions the following pictures:

Near the contact region:

"Near" the fixed support:

Here is also the unconverged stress plot:

In real life I would expect some plastic strain indeed, especially in the contat region, resulting in something like an inprint of the smaller part on the larger one.

In the solver output I see some warnings of "convergence has been achieved in spite of large penetration" during the substeps 1 and 2 (probably because I reduced the contact stiffness with a factor of 0.1). After that, I see messages of "too much penetration" but not this same "convergence in spite of large penetration" as in substeps 1 an 2.

Than in substep 19 (I set it to 20 this time, but tried with 200 also) I got 2 errors that a couple of elements became highly distorted. And the non converged deformation plot shows the deformed elements exactly where the plastic strain occurs near the radii in the contact region, but not exactly in the radii. Actually where the small part has a radius, the bigger one distorts, and vice-versa.

I'll try a larger radius, even though I believe it would no be possible in the design.

Any other ideas?