A dislocation-based hardening model incorporated into an anisotropic hardening approach

The plastic flow behaviors under monotonic and forward-reverse loading were measured and modeled using a simple dislocation density-based model coupled with the homogeneous yield function anisotropic hardening (HAH) approach. The former model captures the effect of dislocation annihilation due to load reversal and the storage of newly generated dislocations that, overall, results in the stagnation of the strain hardening rate. The latter model reproduces the mechanical response of the Bauschinger effect and permanent softening phenomenon. After implementing the constitutive model into a finite element software, a detailed parametric study was performed to clarify the role of each constitutive parameter. In addition, this model was applied for the prediction of the flow curves of three different steel sheet samples under forward-reverse simple shear deformation. It was shown that this approach reasonably well reproduces the complex mechanical behavior of the steel samples. Finally, this physically based constitutive model was used to predict the springback of a realistic part after forming in order to prove its accuracy, robustness and efficiency as compared with another well accepted phenomenological isotropic-kinematic hardening model.