Effects of Residual Stresses on Fatigue Crack Propagation of T-Joint Using Extended Finite Element Method (XFEM)

The welds of T-joints are prone to fatigue cracking owing to stress concentrations and welding residual stresses. Previous studies investigated the crack propagation rate using numerical simulations; however, most employed two-dimensional models and ignored the effect of residual stresses. In this study, reliable temperature and residual stress fields were obtained through numerical simulations and verified experimentally. The effects of residual stresses on crack propagation were then investigated under different loading conditions. The residual stress field caused the direction of crack propagation to shift towards the web and accelerated the crack propagation speed with increasing displacement loading.