Model Integration for Process Simulation

Funding: German Research Foundation (DFG)
Project: SFB/TRR 188 • Subproject S01
Contact: Alexander Schowtjak M. Sc.

Aim of the SFB/TRR 188 is to understand and predict damage. The identification of different material and model parameters is necessary in order to analyze forming processes in terms of damage.

For their determination an optimization-based software tool for the parameter identification of complex material models is developed. To this end, experimental data is compared with simulations for several basic experiments. Local information like displacement
or strain fields (see figure a), which are determined by digital image correlation software, as well as global information such as load-displacement curves are considered. The individual material parameters serve to describe varying phenomena. Thus, certain parameters are evaluated separately through appropriate experiments and examination methods. The nucleation-related part of the Gurson-Tvergaard-Needleman-model can be identified by fitting the evolution to the experimentally determined voids obtained by microstructural investigations (see figure b).

a) Strain field for a tensile test with notched specimen, b) Void area fraction due to nucleation versus equivalent plastic strain