Introduction of a large-strain texture-based finite element method

This Max-Planck project report presents a time efficient and at the same time physically based approach for including and simulating elastic-plastic crystalline anisotropy during complex forming operations of metal polycrystals. The novel procedure is based on the direct integration of spherical crystallographic texture components into a commercial non-linear finite element program package. The method has been developed to perform very fast simulations of large strain industry-scale metal forming operations of textured polycrystalline materials including complete texture update during forming. Instead of using the yield surface concept or large sets of discrete crystalline orientations the method proceeds from a small though physically based set of discrete and mathematically compact Bessel-type Gaussian texture components which are used to map the orientation distribution function directly and in a discrete fashion onto the integration points of a viscoplastic crystal plasticity finite element model. The method merges approaches from crystallography, crystal plasticity, and variational mathematics. It increases the computational efficiency of microstructurebased anisotropy calculations dramatically and thus represents a feasible approach to incorporate and predict anisotropic behavior at the industrial scale. Applications of the new method are particularly in the field of predicting shape-sensitive anisotropic large strain - large scale forming operations such as encountered in the automotive and aerospace industry. This progress report gives an overview of existing anisotropy concepts which are commonly used in conjunction with finite element methods, provides an introduction to the new crystallographic texture component crystal plasticity finite element method, and gives examples of its application