Research advances in fatigue performance of spot joining technology for lightweight materials

The advancement of lightweight automotive technologies has necessitated the adoption of various lightweight materials, leading to the development and investigation of numerous joining techniques. Among these researches, spot joining technology plays a critical role in the automotive sector, as its fatigue performance significantly influences vehicle safety and durability while maintaining structural integrity. Research focused on this technology is essential for enhancing automotive lightweighting initiatives. This article comprehensively reviews the fatigue performance associated with spot joining technologies. It examines key factors influencing fatigue performance and outlines various methods for predicting fatigue life. The discussion encompasses the spot joining technologies currently employed in automotive lightweight sheet materials, concisely evaluating their application status and developmental trends. The fatigue testing of spot joining joints is analyzed from four distinct perspectives: environmental factors, residual stress, loading conditions, and other aspects, all of which impact the fatigue performance of the joints. Moreover, five primary methods for predicting fatigue life in spot joining technology are detailed. Finally, the article concludes by offering insights into potential future research avenues aimed at enhancing the understanding of fatigue performance in spot joining technologies.