Modelling Metals At Finite Deformation

Abstract

AbstractDuring metal forming processes, substantial microstructural changes occur in the material due to large plastic deformations leading to different mechanical properties. It is of great interest to predict the behaviour of these materials at different fabriction stages and of the final product.At first glance, the behaviour of metals can be approached by an elastoplastic isotropic material model with a volumetric‐deviatoric split and isotropic hardening. In order to perform the calculations, a logarithmic strain is considered in the principal directions of stress and strain space, allowing to make predictions even at finite deformations.Because of the actual nature of metals, the crystalline structure, the deformation at the microstructural level is much more complex. Due to the mathematically algorithmic form of an elastic predictor and a plastic corrector, the elastoplastic model can be extended to crystal plasticity which is similarly handled in terms of a critical resolved shear stress on defined slip planes in the crystal. Hardening can be modelled through a viscoplastic power law. (© 2010 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)