what is the reason for Large element deformation?

Hi my Friends,

I am doing abaqus run for a copper specimen under hydrostatic pressure. The magnetude of pressure is in order of several Giga Pascals. In my material definition, I have defined stress-strain flow up to strain of 0.4. But as you can see in attached photo, some elements show very large deformation (considerably larger than 0.4). Knowing that I have not defined stress strain behaviour for srain greater than 0.4, how this can be occure? Unfortunately, niether adaptive meshing nor element deletation were not eliminate this issue!!

Best Thanks