Multiaxial fracture of DP600

The stress state dependent fracture behavior of DP600 steel at the continuum level was investigated through a combined experimental and computational approach. A range of specimen geometries were used to probe the fracture behavior of the material under different stress states. Using an isotropic J2 plasticity framework, finite element simulations of all experiments captured the experimental force displacement curves, and provided information on the evolution of equivalent plastic strain, stress triaxiality, and Lode angle parameter with applied deformation at the location of eventual fracture initiation. The calculated local failure strain as a function of stress state was used to calibrate the modified Mohr-Coulomb (MMC) fracture model. A comparison of the calibrated MMC model with previously reported results in literature highlights the importance of calibrating the fracture model over a wide stress state range to fully and accurately describe the fracture behavior of the material.