Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
786193 | International Journal of Plasticity | 2014 | 24 Pages |
•RTM is used to provide the computational efficiency while keeping the physics-based nature of the polycrystalline model.•A new hardening law featuring two hardening matrices for slips systems. Good plasticity modeling for more than 30 loadings.•A novel initial back stress model at slip system level, which is an effective and practical way to describe history effect.•The capability of modeling cross-hardening at the macroscopic level is validated through two non-proportional tests.•The applicability of the present model to large-scale practical problems is demonstrated through structure validations.
This paper works on the macroscopic modeling of the anisotropic plasticity of a 6260-T6 thin-walled aluminum extrusion with a focus on the large strain multi-axial deformation with Strength-Differential Effect (SDE). Based on the framework of the self-consistent polycrystalline plasticity, the recently developed Reduced Texture Methodology (RTM) (Rousselier et al., 2012) is employed to provide the computational efficiency needed for industrial applications while keeping the physically-based nature of the plasticity model. In particular, the new model features a novel hardening law at slip-system level to better capture large strain behaviors, as well as a generic method designed to describe the stress/strain history effect. All model parameters (including texture) are identified from mechanical experiments using a special optimization procedure. An extensive experimental program covering more than 30 distinct multi-axial stress states with both proportional and non-proportional loadings is used to calibrate and validate the present model. Both full- and reduced-thickness specimens are tested to capture the through-thickness heterogeneity of texture and grain size. It is shown that the present model predicts well the stress–strain responses in most of the multi-axial loading conditions which have been tested. Moreover, the model is able to capture various interesting behaviors of the present material during plastic deformation, including anisotropy, through-thickness heterogeneity, SDE of tension/compression or shear, and cross-hardening during non-proportional loadings. Furthermore, successful simulation of two structural level tests including a circular punch indentation and a three-point bending shows the applicability and potential of the new model in industrial practices.