Fatigue Life Prediction of Butt Weld Joints with Weld Defects at Multiple Locations

Abstract

A numerical model developed using finite element software is used to determine the fatigue life of an arc-welded butt joint with weld defects: lack of penetration, lack of fusion, and undercut, which occur predominantly in welded structures. High-strength, tempered, and quenched fine grain ASTM A517 grade F structural steel, widely used in welded structures, is selected as the base material. The finite element analysis approach adopted in the present work is validated using the experimental and analytical results by performing a benchmark study. The validated numerical approach is then used to generate datasets for developing an empirical model for predicting the fatigue life of a butt joint with defects, modelled as cracks at specific locations, subjected to bending and/or membrane stresses. An experimental investigation was undertaken to validate the empirical model. The influencing parameters are ranked based on their severity on the fatigue life of butt joint.