ABAQUS CAE simulation of indentation

Dear All,

I have the following problem. I simulate an indentation in two steps. At first step the indenter penetrate to the material. At the second step it withdraws from it. The problem, at the second step force simply drops, although the behaviour of material is elasto-plastic.. What could be the reason? Incorrect boundary conditions, very soft behaviour of material??? Specialists, please help.

Best regards

ABAgirl