Self-piercing riveting process: An experimental and numerical investigation

The self-piercing riveting is a young technology for joining sheet metals in automotive structures. In this paper, the riveting process has been simulated numerically using the finite element code LS-Dyna. A 2D axisymmetric model was generated including two sheets to be joined, rivet and tools. The rivet and tools geometries are based on the Böllhoff standards. An implicit solution technique with r-adaptivity has been used. The advantages and the limits of using r-adaptivity in this class of metal forming process are discussed. In addition, parametric studies on important parameters for the forming process, i.e. friction, mesh size and failure criteria are presented. In order to validate the numerical simulation of the riveting process, a new test device was developed in order to record the force applied on the rivet during the riveting process. An extensive experimental program on specimens made of aluminium alloy 6060 in two different tempers, T4 and T6, has been used as a database for the validation of the numerical simulations. The results show the capability to simulate the riveting process for different combination of plate material and rivet geometries.