Finite-Element Simulation and Experimental Validation of a Plasticity Model of Texture and Strain-Induced Anisotropy

The objective of this study is to present a new constitutive model of plastic behaviour of metal sheet, which takes into account variables that may influence single and especially multistage operations. This new approach is based in models of texture and strain-path induced anisotropy that captures the influence of the microscopic physical mechanism, which governs the macroscopic plastic behaviour, i.e. crystallographic texture and dislocation structures. The obtained model is of vital importance for the development of an accurate finite element tool for virtual product development of all kinds of sheet metal parts. Such constitutive model has been integrated into a general-purpose finite element code. Two industrial relevant metal sheets of deep-drawing quality are considered in the present study: a low carbon steel and an aluminium sheet 5182. Detailed experimental studies have been performed to fully characterize their crystallographic texture and hardening behaviour upon strain path change. A simple test case for basic verification and experimental validation is defined. This test consists of a two-stage operation: a biaxial stretch followed by a uniaxial tension. Strain distributions and tensile curves have been experimentally assessed and they are compared to FE predictions.