Influence of Rivet Tip Geometry on the Joint Quality and Mechanical Strengths of Self-Piercing Riveted Aluminium Joints

Abstract

Due to the drive from legislations, fuel efficiency, and CO2 emission, the application of aluminium lightweight structures in automotive industry have been increased significantly. Self piercing riveting (SPR) has been one of the major joining technologies for aluminium structures due to its advantages to some traditional joining technologies. There are some standard parameters that will influence the joint quality and mechanical strengths of an SPR joint. However, even for the same parameters used, sometimes the joint quality and mechanical strengths of SPR joints could still be significantly different, which may cause joint failure or strength reduction. One reason found is the variation of rivet specifications between different batches. In this paper, the influence of rivet tip geometry on the joint quality and mechanical strengths was studied. The results showed that rivets with sharper tips flared more during riveting process, and joints with sharper rivets had higher lap shear strength; however, the influence of rivet geometry on T peel strength could be different for different rivets, and rivet tip geometry did not have an obvious influence on joint fatigue strengths.