A crystal plasticity-based constitutive model for ratchetting of cyclic hardening polycrystalline metals

Abstract

A crystal plasticity-based constitutive model is developed by modifying the second item of Armstrong–Frederick (A–F) nonlinear kinematic hardening rule and introducing self-hardening and latent hardening representing the dislocation interaction between slip systems. With the help of β scale-transition rule, the cyclic stress–strain responses of polycrystalline metals can be obtained from the single crystal constitutive model. Then the developed model is applied to describe the cyclic deformation behavior of a face-centered cubic polycrystalline metal, i.e., 316L stainless steel. The predicted results of the model compared with the experiments of 316L stainless steel show that the model can not only simulate the uniaxial and multiaxial ratchetting of the face-centered cubic crystal material during the asymmetrical stress-controlled cyclic loading, but also describe the cyclic hardening characteristics of materials under symmetrical strain-controlled cyclic loading. Meanwhile, the model is capable of predicting uniaxial ratchetting of different orientations at single crystal scale.