A novel method for evaluation of welding residual stress redistribution during fatigue crack growth

A novel methodology for evaluation of welding residual stress (WRS) redistribution during fatigue crack growth (FCG) was proposed in this paper and some necessary equations were derived. By using strain gauge rosettes (with three strain gauges of different directions manufactured on one substrate) attached to the surface of the sample along the potential crack propagation path, the amounts of strain change were collected by a dynamic strain testing system and the corresponding amounts of WRS redistribution were calculated following our equations, which were used to characterize the WRS redistribution thereafter. Experimental tests were carried out to determine the redistribution of WRS during FCG of a high strength steel welded joint employing our proposed methodology. It turned out that this straightforward methodology was capable of accurately capturing the WRS redistribution during FCG relative to an analytical method proposed previously in the literature.