Abstract
This study aims to compare the influence of residual tensile and compressive stresses resulting from welding on fatigue crack propagation. The development of fatigue fractures within zones characterized by residual tensile and compressive stresses is investigated using numerical simulations. A quantitative evaluation of the impact of residual stresses on crack propagation is conducted by comparing the crack opening loads in cases with and without residual stresses. And a series of comparative analyses of crack closure parameters is performed to examine the effects of changes in load level (e.g., load ratio, maximum load, and overload ratio) on the release and redistribution of welding residual stresses. The research findings indicate that the influence coefficients for residual tensile stress and compressive stress on fatigue crack propagation are 0.65 and 1.5, respectively. Increasing cyclic loading amplitude and overloading are beneficial for reducing the difference in crack closure parameters between cases with residual stress and those without, weakening the influence of welding residual stress on crack growth.
