A New Crystal Plasticity Based Constitutive Model Incorporating Backstress for FCC Polycrystals

To overcome the current limitations of phenomenological models of predicting material response under complex strain path deformation a new hardening law is proposed. The model is calibrated with experimentally measured microstructural features during deformation. The new hardening law, in contrast to existing laws, can be completely determined from observations with very few free parameters. The model accounts for hardening due to interactions with forest dislocations as well as with dislocation cells. The interaction with dislocation cells is estimated by using backstress effect. The new model is calibrated with experimental uniaxial tension data for the aluminum alloy 5754. This model allows us to examine the inhomogeneous distribution of slip arising from microstructural features and provides a powerful tool to investigate formability in FCC polycrystals.