Microscale modeling of damage mechanisms in dual‐phase steel DP800

Abstract

Dual-phase steels are very popular in the automotive industry due to their high strength while maintaining good formability. The macroscopic formability of this polycrystalline material is governed by deformations and damage mechanisms at the microscale. To describe the mechanical properties associated with these mechanisms, a crystal plasticity theory is coupled with interface models and integrated into representative volume elements (RVEs) of DP800 in a thermodynamically consistent manner. The interface models capture decohesion at the grain boundaries via a cohesive interface model as well as the initiation and propagation of micro-cracks (damage) within the quasi-brittle martensite phase via a phase-field approach. In this contribution, the focus lies on the conceptual framework combining above models in a finite element setting. Furthermore, the interaction and activation of the different (damage) mechanisms will be shown in order to highlight the predictive capabilities of the presented framework.