Fatigue analysis of post-weld fatigue improvement treatments using a strain-based fracture mechanics model

Untreated and post-weld treated (peened) fatigue details common to welded steel structures are analyzed herein using a strain-based fracture mechanics model. The model is first described and then evaluated by comparison with data from several test-based studies as well as analytical results obtained using two linear elastic fracture mechanics (LEFM) models. The strain-based model is then used to perform several parametric studies. Based on the results of these studies, loading conditions are identified for which ignoring the nonlinear material behaviour may lead to overestimation of the post-weld treatment benefit measured as in increase in the fatigue life of the weld.