Summary of research on fatigue life assessment of welded joints

Abstract

In order to deepen the understanding of the fatigue problem of welded joints, this paper compares the research principles and limitations of four commonly used welding fatigue life prediction methods, including nominal stress method, hot spot stress method, notched stress method and fracture mechanics method. The nominal stress method is the most widely used in the four fatigue prediction methods, but it is too conservative. The hot spot stress method has high calculation accuracy, but it cannot fully reflect the fatigue behavior of the joint details. The notch stress method includes all sources of stress concentration, but the S-N curve recommended by IIW does not apply to the fatigue evaluation of butt joints. The fracture mechanics method is applicable to the crack propagation stage of joints. Through the analysis and research on the fatigue life assessment methods of four welded joints, it lays a theoretical foundation for the fatigue life prediction of welded joints.