Study on GISSMO fracture model of hot-stamped Tailored-Tempering-Properties parts

Abstract To accommodate the varying mechanical demands in different areas of vehicle components, the Tailored-Tempering-Properties technology of hot-stamped parts of high-strength steel came into being. This research crafted a segregated hot and cold partition die system to fabricate U-shaped parts from 22MnB5 with Tailored-Tempering-Properties. The sides and bottom surfaces of the hard and soft zones of the U-shaped parts were sampled, and uniaxial tensile experiments were carried out to obtain the stress-strain curve, tensile strength, and elongation. In addition, notch, shear, and tensile shear sampling were carried out in the soft area at the bottom flange of the U-shaped part, and the force-displacement curve and fracture strain under different stress conditions were determined by tensile test. The GISSMO fracture model was selected to simulate the failure fracture of the material, and the parameters were obtained by Hypermesh pretreatment, LS-DYNA solution calculation, and LS-OPT optimization. Finally, the GISSMO fracture model suit for the soft zone of 22MnB5 U-shaped parts was obtained to characterize and predict its fracture behavior, which is an essential basis for guiding the design and optimization of parts.