Fatigue crack growth of butt welded joints subjected to mixed mode loading and overloading

Abstract

Since welded joints in structures are known to be critical regions for crack initiation and growth, study of fatigue crack growth behavior of welded joints under various loading scenarios are essential. In present study, two groups of experiments were conducted. At first, fatigue crack growth behavior of Al5083 butt welded joint subjected to mixed mode loading with constant amplitude has been studied. Afterwards, fatigue crack growth behavior of butt welded joints subjected to mixed mode single overload has been investigated. The sensitivity of the crack growth retardation behavior to post-welding heat treatments was also studied. Considering the effect of residual stress on fatigue crack growth, a modification to the Wheeler model was proposed to improve the accuracy of retardation prediction after applying a mixed mode overload.