Effect of stress state on the failure behavior of a dual phase steel

The failure strain of metallic materials depends on the stress state. In this work a dual phase steel (DP600) was investigated both experimentally and numerically. To study the dependence of damage behavior on stress triaxiality and Lode parameter, experiments on bar and flat tensile specimens (smooth and notched with various notch radii), on plane strain specimens with various radii, on torsion specimens and on Nakazima specimens were performed. A general damage model based on a critical failure strain was developed. FE simulations were performed to determine the local values of triaxiality and Lode parameter for each specimen type.