I've been trying to figure out difference between isotropic and kinematic hardening (modeling plasticity in metals). As I see,kinematic hardening can model reversible nbehaviour of metals (Bauschinger effect). In isotropic hardening, the yield surface increase in size, but remain the same shape, as a result of plastic straining. That is, if the yield surface is represented by a cylinder of radius "A" then an increase in the radius denotes an increase in the yield stress as a result of plastic straining. However,this cannot capture Bauschinger effect as when unloaded and reloaded in compression (if earlier was loaded in tension) there is no sign of reduction in palstic limit. As I see, in kinematic hardening there the yield surface translates from its original position (thus there being a change in center of cylinder) which makes the difference. Can anyone explain this more clearly (or correct me)-with a physical intuition?