EVALUATION METHOD FOR CONTROLLING FACTORS OF FATIGUE PERFORMANCE BASED ON MULTI-SECTION SHAPE ANALYSIS OF WELDED JOINTS

Abstract

 Stress concentration significantly influences fatigue performance of welded joints. While it is possible to evaluate the stress concentration of arbitrary shapes by FEM analysis of measured data, it requires a considerable computational cost. Therefore, an evaluation formula that allows for a simple estimation of the stress concentration factor has been proposed. A method that facilitates the unified evaluation of all geometry parameters has also been proposed. Some certain issues of a similar method that have been used for multi-section analysis have been pointed out. Consequently, this study aims to develop a technique for evaluating the dominant factors affecting fatigue performance based on multi-sectional shape analysis of welded joints. The study confirmed that the prediction accuracy of crack initiation location was high when the median value was used among the stress concentration factors (𝐾𝑡) of multiple cross-sections. Additionally, through the evaluation of fatigue performance, it was confirmed that the misalignment and angular deformation are two important factors that significantly affect the fatigue performance of welded joints.