Computational homogenisation of polycrystalline elastoplastic microstructures at finite deformation

This dissertation presents a methodology to develop effective constitutive models for materials with microstructures at large deformations based on a concept of computational homogenization. The examined microstructure is of body-centered cubic polycrystalline nature and consists of Voronoi cell shaped grains. Experimental pole figures and Schmid factors from SEM and EBSD measurements of pre-textured DC04 serve as validation criteria for the pre-textured deformed microstructures. The numerical simulations are carried out on an irregularly shaped RVE. Specific measures are considered to get a reliable and statistically representative response, and with optimization techniques, material parameter sets can be determined for an assumed effective material model. The effective model is validated with results from uniaxial and biaxial experimental tests in monotone and cyclic loading with DC04 sheet metals.