Fast estimates of evolving orientation microstructures in textured bcc polycrystals at finite plastic strains

The paper presents a framework for a fast computational estimate of the texture evolution in bcc polycrystals. The underlying basis is a Taylor-type approach to rigid plasticity in bcc crystals, where the decision of slip activity is based on a purely geometric argument in terms of the rate of total deformation. The core part of the method is a new algorithm for rate-independent rigid crystal plasticity, which uses lattice rotations parametrized by Rodrigues vectors as history variables. We show that such a geometric estimate of the orientation microstructure provides very good approximations when compared with experimental results of bcc crystals. It is shown for several deformation modes of polycrystalline aggregates, that the geometric approach predicts the texture evolution very well at large strains. In contrast to standard approaches for the analysis of texture, the proposed new method is extremely robust and fast even for a high number of discrete grain orientations. As a consequence, such an approach provides a perfect base for large scale computations of texture development in polycrystals.