Static and Fatigue Strength Evaluation of Clinched Joints in an Aluminum Alloy

This paper presents the static and fatigue strength evaluation of clinched joints in 6111-T4 aluminum alloy sheets. Clinched joints are mechanical joints produced a cold forming technique using a small die-punch combination. A design of experiments approach is used to determine the optimum die-punch combination that produces the least variation in the static pull-out load in single lap shear tests. Fatigue S-N curves are determined for several different clinched joints in load-controlled fatigue tests with the load ratio equal to 0.1. The effect of heat exposure, typically experienced in paint ovens, on the static strength as well as fatigue S-N behavior are also examined.