Hi, I encounter a difficulty in modeling the nanoindentation using Abaqus FEM. I have a 2D block of 20x20 um, I use a elasto-perfect-plastic material: E = 80 GPa, possion's ratio = 0.17, yield stress = 75 MPa at plastic strain = 0. I use an indenter of angle 77 degree as a rigid body pushes against the block to simulate nanoindentation. 

The test always fails with "too many attempts made for this increment". I understand that this is due to once the stress reaches yield, the deformation becomes too quick and those cause some problems. I did try use pure elastic material, or increase the yield stress, both of them works better. But I really want to know how can I do a successful simulation with my current setting.

I see many papers using elasto-perfect plastic materials with low yield stress and the simulations were all good. Not sure how they managed to do that.

Thanks.