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Abstract

In order to model the mechanical performance of heterogeneous (multiphase) materials on microstructural length scales we need to have three-dimensional (3D) representations of realistic microstructures. Based on representative volume elements (RVE) describing such microstructures and the knowledge of the mechanical properties of all individual phases, micromechanical modeling can predict changes of mechanical properties of materials with changes in their microstructures. While experimental characterization and advanced reconstruction methods can give us detailed insight into real 3D microstructures, artificial microstructures can be used to identify the influence of certain microstructural components on the global mechanical behavior by parametric studies. Such artificial microstructures can for example be obtained by Voronoi constructions or by phase field simulations. Of course any artificial microstructures must be statistically equivalent to their real counterparts in aspects like volume fraction and size and shape distributions of the individual phases. On the example of martensitic steels, which posses a hierarchical microstructure over several length scales, it will be demonstrated how RVE-based micromechanical simulations and homogenization methods can be applied to make predictions on macroscopic mechanical properties. Furthermore, it will be shown that microstructures are evolving with time, which must be taken into account for many applications.