Determination of Modified Mohr-Coulomb Damage Model Parameters for DH780 Steel in Finite Element Analysis

Abstract

In sheet metal forming processes, tearing problems might be occasionally encountered due to many reasons such as incorrect forming parameters. The trial and error methods that are used to solve such problems, on many occasions, are time-consuming and inefficient in terms of finding the correct forming parameters or die design for the forming process. The finite element analysis method, on the other hand, can be used as a tool that is both time and cost-saving. However, in order to effectively exploit the use of finite element analysis in sheet metal forming operations, the material that is used to be formed needs to be well characterized in terms of its hardening behaviour and failure criteria. In this study, a TRIP-aided DP steel (DH780) has been tensile tested in three different deformation conditions (uniaxial, plane stress and shear) and the parameters of its hardening model (Hollomon) and failure criteria (Modified Mohr-Coulomb) have been determined. According to the simulation results, obtained hardening parameters are able to describe the flow behaviour of the steel and the used failure criterion is able to predict the experimental failure correctly in each deformation condition.