Evolution of yield surface in the 2D and 3D stress spaces

摘要: Abstract Initial and subsequent yield surfaces for 6061 aluminum, determined by a method of automated stress probing, are presented in the 2D (σzz − σθz) 3D (σθθ − σzz − σθz) spaces. In space, at small pre-strains show noses unapparent cross effect. At larger pre-strains, they become ellipses with positive initial surface is not well described von Mises criterion due to material anisotropy. The various torsional obvious rotation around σzz axis but do rotate when subjected axial pre-strains. Therefore, behavior pre-strain path dependent. space emphasis present paper. Coupled axial–torsional torsion after also same that used determine surfaces. This information useful verification constitutive models.