Analysis of Stress Intensity Factor due to Surface Crack Propagation in Residual Stress Fields Caused by Welding

(Comparison of Influence Function Method and Inherent Strain Analysis)

Abstract

Stress intensity factors due to surface crack propagation were analyzed by using the influence function method and inherent strain analysis of the residual stress fields caused by welding. The initial residual stress in a plate welded-butt joint was calculated by using inherent strain analysis, and the redistribution of residual stress and the stress intensity factor due to crack propagation were analyzed as changes in the structure's shape. Stress intensity factor was also calculated by using an influence function database. The stress intensity factor in the residual stress fields due to crack propagation obtained by using inherent strain analysis completely agreed with that obtained by using the influence function method. The results of the crack propagation analysis were compared with the experimental results of a fatigue test. It was validated that both the inherent strain analysis and the influence function method were efficient for analyzing stress intensity factors in residual stress fields caused by welding.