Determination of mechanical properties of polycrystals by using crystal plasticity and numerical homogenization schemes

The modeling and simulation of metal forming processes is typically based on experimental data. Unfortunately, the experimental investigation of the mechanical behavior and the related properties of polycrystalline materials is a difficult task, because only limited stress and strain states can be investigated experimentally. For example, the testing of sheet metals is simple under tension, complex under compression due to buckling, and costly under biaxial load. In order reduce these drawbacks, a virtual testing concept is applied. In this concept, the behavior of single crystals is modeled by crystal plasticity and the behavior of polycrystalline microstructures is represented by using finite element solutions of periodic microstructures. The success of the strategy is validated on the mild steel DC04. In order to calibrate the virtual testing, only a small number of experimental information like crystallographic and morphologic texture and tension test data will be incorporated. Other quantities, like the tension behavior in other directions, the multi-axial material behavior, as well as the Lankford coefficients and the initial yield behavior will be predicted by virtual testing and compared to experimental data for validation. The demonstrated approach for calibrating the virtual testing and for predicting key material values is successful and leads to valuable contributions to the modeling and simulation of sheet metals.