Characterisation of force–displacement curve in self-pierce riveting

A systematic study of the force-displacement curve of the self-piercing riveting (SPR) process and associated sample characterisation have been carried out in this work. Carbon steel sheet with three different thicknesses and steel rivets with three different hardness levels have been used to examine their impact on the force-displacement characteristic curve. The force-displacement curve is segmented into four different stages, which give the signature of the quality of the joint depending on different process variables. This study shows that the force-displacement curve can be used to monitor the quality of the joint within the same process parameters (rivet length and hardness, total stack thickness and die geometry).