Design of Helical Self-Piercing Rivet for Joints in Variable Sheets

A self-piercing rivet (SPR) is a mechanical component for joining two or more dissimilar materials such as aluminum alloy and steel. The SPR directly pierces the upper sheet and joins with the lower sheet without the piercing process. Use of advanced high-strength steel is being tried to reduce weight of the vehicle. A steel sheet with a tensile strength 590 MPa grade form a 1470 MPa grade is applied to the automotive body. The helical SPR is required to pierce steel sheets having tensile strength greater than 1180 MPa. Each type of SPR requires different parameters such as for anvil and punch unit. Considering the convenience of operation in production line, it is desirable to use one type of SPR. In this study, simulations on helical SPR and variable steel sheets were carried out to determine the optimal riveting conditions using the commercial FEM code, DEFORM-3D.