Overview of Fatigue Research of Spot Welded Joints

Abstract

：The research on fatigue of spot welded joints in recent decades is summarized comprehensively. The achievements of research on fatigue of the spot welded joints are described systematically from 4 aspects, including numerical analysis, experimental analysis, finite element analysis, and fatigue assessment methods. The numerical analysis methods of spot welding such as static theory, local stress, structural stress and fracture mechanics are summarized. The failure mode, failure mechanism and fatigue life of spot welded joints are studied by test methods such as static test, tensile-shear fatigue test, peel test and notch test. The characteristics, modeling methods and applicable scopes of 8 kinds of finite element models of spot welding joints are compared and summarized, and the C_WELD model and C_BAR mode are considered to be suitable for large spot welding structures. The applicable conditions, applicable objects, and evaluation effect of various fatigue assessment methods for spot welded joints such as load-life method, nominal stress method, hot spot stress method, and equivalent structural stress method are summarized, and it is believed that the equivalent structural stress method is worthy of popularization and application in the field of engineering. Finally, the existing problems and further research directions are reviewed and discussed, which would provide some guidance and assistance for further research on fatigue of spot welded joints.