Modeling of component failure due to notch effects in press-hardened steel caused by mechanical and thermo-mechanical joints under crash load

The increasing application of press-hardened steel in combination with aluminum sheets in the construction of car bodies results in the use of mechanical joining techniques such as self-piercing riveting and thermo-mechanical joining techniques such as resistance element welding. These joints generally represent a notch within the component. The cause of the notch effect is different for the investigated joining techniques and can be distinguished in a geometrical notch and a metallurgical notch. Riveted joints result in a pierced hole with high plastic strains at the edge and thus represent a geometrical notch. Thermo-mechanical joints in press-hardened steel result in a softened heat affected zone (SHAZ) around the weld due to the applied heat during the joining process.