Evaluation of long-term design strength for aluminum alloy SPR joint after aging

Abstract This study systematically investigates the static mechanical properties and failure behavior of self-piercing riveted (SPR) joints in aluminum alloy 5A06 after time aging and temperature aging. The research encompasses five categories of joint specimens: original specimens, 1-year-aged specimens, and corresponding heat-treated samples at 200 °C, 300 °C, and 400 °C. Results confirm that strain aging reduces the peak strength of the joints. Using an efficient predictive model, the joint’s strength decreased by 15% and 40% after 1 and 5 years, respectively. To assess the long-term performance of SPR connections, a design point was proposed, calculated by determining the minimum value between the 5% lower limit, derived statistically, and the sample’s average value multiplied by a safety factor of 0.6. A comparison of results shows that this method is a reliable tool for predicting the long-term performance of 5A06 joints in future applications.