Bauschinger effect

Summary

The Bauschinger effect is the drop of the yield stress in the reverse direction after a material has been plastically deformed in one direction. Stretch a metal beyond yield and then compress it. It yields again in compression at a stress of smaller size than the tensile stress it reached. It shows that work hardening is not just a growth of the elastic range but also a shift of it. In plasticity theory it is modelled by kinematic hardening, a translation of the yield surface described by a back stress.