A constitutive model for uniaxial/multiaxial ratcheting behavior of a duplex stainless steel

Abstract

In the framework of rate-independent plasticity theory, a constitutive model capable of simulating the uniaxial strain cycling and the uniaxial/multiaxial ratcheting responses of a super duplex stainless steel (S32750) which has cyclic hardening characteristics under strain-controlled cyclic loading is derived. In the developed constitutive model, the steady cyclic flow was reflected by the nonlinear evolution of the proposed kinematic hardening rule based on the Chaboche model and the Burlet and Cailletaud model; the cyclic hardening was modeled by the evolution of isotropic hardening; the strain memory effect was also considered through the asymptotic value of the isotropic hardening variable. Verification of the proposed constitutive model was achieved by simulating the uniaxial/multiaxial strain- and stress-controlled cyclic loading tests and comparing the predicted results with the experimental measurements.