Material models to study the bauschinger effect on an aluminum shear test specimen

Abstract

Sheet metal forming processes generally involve complex loadings and nonlinear material models. Combinations of drawing, re-drawing and/or reverse drawing operations commonly induce cyclic loads with non-proportional strain paths, leading to Bauschinger effects that can not be predicted by conventional isotropic hardening laws. In order to properly represent this effect, it is also required to accommodate an appropriate kinematic hardening model along with an anisotropic yield function. In this work, two different approaches will be used to predict the Bauschinger effect for an Aluminum shear test specimen: the rate dependent crystal plasticity model of [1, 2] and a new combined isotropic/kinematic hardening model based on the two yield surfaces approach (loading and boundary yield surfaces), as recently proposed by [3].