Calibrating a homogenized polycrystal model from large scale FE computations of polycrystalline aggregates

Homogenization-based estimates of the effective behaviour of elastoviscopla stic polycrystals usually resort to approximations like that of an inclusio n embedded in the homogeneous equivalent medium in the case of the self-con sistent scheme. We propose here to replace this idealized intermediate prob lem by the actual computation of a polycrystalline representative volume el ement. Computations of a cube made of 200 zinc grains are presented and use d to calibrate the scale transition rule of a simplified homogenized polycr ystal model. A coupled identification procedure is presented to determine b oth intragranular material parameters and scale transition parameters from experimental tension, creep and relaxation tests.