I use a predefined field to simulate a residual stress state in a part. My predefined field does not exactly leave the part in equilibrium, so I include a simulation step to allow equilibrium to be achieved. When I examine the stress state of the part after the equilibrium step, I've noticed that the component of stress near the free surfaces of the part is nonzero! This obviously doesn't match reality. Is this a known convergence issue? Is there some way to better simulate the process of finding a stress state which leaves the part in equilibrium?

Abaqus ​​​​​​​