Damage modeling in the numerical simulation of mechanical joining processes

Mechanical joining processes are increasingly being used as an approach towards multimaterial design concepts to reduce weight of vehicles and thus CO2 emissions. As the requirements of customers in terms of comfort and safety are increasing, the cost pressure is also rising and the product development cycles are steadily decreasing. These aspects make it necessary to use simulation methods to qualify joining processes for new developments in early development phases. In the simulation of mechanical joining processes, it is important to predict the damage and fracture behavior of the material. Due to lack of an accurate damage model, the accuracy of joining process simulation is significantly limited. A precise modeling of process-induced damage accumulation in mechanical joining simulation, enables not only an understanding of the acting mechanisms but also an optimization of the joint with respect to the load-bearing capacity and the energy absorption. The aim of this work is to describe the evolution of ductile damage as well as the failure behavior of upper sheet in the 2D simulation of self-piercing riveting process. Furthermore, it is inteneded to investigate the influence of pre-damage induced by joining process on the strength of the joint.