Modeling and Parameterization for a 3D Simulation of Clinching with an Extensible Die

Lightweight construction is a powerful tool for reducing energy consumption in modern automotive engineering. Mechanical joining technology such as clinching is increasingly being used to implement different types of lightweight materials in the body-in-white. In addition, numerical dimensioning is gaining in importance in the development process. While clinching with a rigid die can be simulated realistically using a 2D axisymmetric simulation, it is not feasible for extensible dies due to geometry and kinematics of the die-intern lamellae, which do not fulfill the assumption of axial symmetry. Therefore, a 3D simulation is necessary. Clinching with extensible die creates a joint, which has a varying neck thickness - undercut profile depending on the microsection direction. To predict the joint geometry, a comprehensive experimental parameterization is necessary for clinching with a rigid die, as recent studies have shown. The aim of this investigation is to parameterize the joining process in terms of friction and to develop a predictive 3D-simulation. Two novel friction test beds are used to investigate the tribological conditions in the process. On the one hand, a rotational test bed is used to identify the friction conditions between tools and joining parts, on the other hand, a translational friction test bed is used to parameterize the die-internal contact between lamella and die running surface. Based on the experimental friction investigations a 3D joining process simulation is carried out and compared to experimental joints. For this purpose, process curves and microsections are used as comparative instruments. The investigations are providing the basis for the process chain simulation of clinching with extensible die.