Fatigue Crack Growth on Double Butt Weld with Toe Crack of Pipelines Steel

Abstract

The welded structures have a broad applicability (car industry, aeronautical, marine, pipelines, etc.). The welding being an assembled process, presents both advantages and disadvantages. A simple existing defect after welding can generate a catastrophic fracture. This work studies the fatigue crack growth of double butt weld with toe crack. Two types of pipeline material are studied with knowing API 5L grades X60 and X70 where tension form of loading is applied. In order to predict the fatigue behavior of the welded structure, a constant amplitude loading is applied where the influence of the stress ratio over the fatigue life is presented