Finite element modeling of crystal plasticity with grains shaped as truncated octahedrons

Different modeling strategies are tested for the prediction of texture development and microscopic strain heterogeneity in cold-rolled ULC steel and in multiphase steel under uniaxial tension. The polycrystalline aggregate is represented by a finite element mesh that is loaded under periodic boundary conditions. Grains are shaped as cubes or as truncated octahedrons, defining three levels of mesh refinement. Simulations rely on a simplified implementation of crystal plasticity, in which elastic strains are considered infinitesimal. The constitutive law is integrated fully implicitly in a reference frame bounded to the crystal lattice. Accuracy of the time-integration procedure is assessed by referring to some predictions of the crystal plasticity algorithm developed by Kalidindi et al. [Crystallographic texture evolution in bulk deformation processing of FCC metals. J. Mech. Phys. Solid 40 (1992) 537–569]. Then, results of the micro–macro modeling are compared to experimental data. It is found that the simulations with truncated octahedral grains yield improved predictions compared to those with cuboidal grains.