Hybrid Micro‐Macro‐Modeling of Evolving Anisotropies and Length Scales in Finite Plasticity of Polycrystals

Abstract

AbstractThe paper focuses on an efficient multiscale approach to the description of evolving anisotropies in polycrystals. The predictive description of complex overall effects needs multiscale methods, taking into account basic ingredients of the material microstructure by model‐inherent scale‐bridging techniques. Straightforward homogenization‐based multiscale methods, such as FEM2 type two‐scale bridgings, are too time consuming for the solution of real engineering problems. A computationally manageable approach is provided by hybrid micro‐macro‐modeling techniques, which combine a purely macroscopic modeling with selected microstructural bridging techniques. Of particular importance are crystal reorientation mechanisms, which cause texture‐based anisotropies at the macroscale. The coupling is realized by homogenization‐based definitions of macroscopic structural tensors, which account for the evolving orientation texture. A crucial aspect is the combination of this hybrid texture modeling with further anisotropy effects, caused by dislocation‐structures. They are mainly responsible for hardening effects related to changes of the strain path. Furthermore, a particular account is taken on size effects and length scales by embedding the hybrid modeling technique into an extended theory of gradient‐plasticity. This results in a computationally efficient hybrid two‐scale model for polycrystalline plasticity, whose capability is demonstrated by means of representative benchmarks. (© 2011 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)