A non-linear kinematic hardening function

Based on the classical theory of plasticity and accepting the von Mises criterion as the initial yield criterion, a non-linear kinematic hardening function applicable
both to Melan-Prager's and to Ziegler's hardening rule is proposed. This non-linear hardening function is determined by means of the uniaxial stress-strain curve, and any such curve is applicable. Tne proposed hardening function considers both the problem of general reversed loading, and a smooth change in the behaviour from one plastic state to another nearLying plastic state is obtained. A review of both the kinematic hardening theory and the corresponding non-linear hardening assumptions is given, and it is shown that material behaviour is identical whether Nelan-Prager's or Ziegler's hardening rule is applied, provided that the von Mises yield criterion is adopted.