Analysis of Stress Intensity Factor due to Surface Crack Propagation by Using Influence Function Method and Inherent Strain Analysis in Residual Stress Fields Caused by Welding

Stress intensity factor due to surface crack propagation was analyzed by using the Influence function method and inherent strain analysis of residual stress fields caused by welding. Initial residual stress in a plate-welded butt-joint was calculated by using inherent strain analysis, and redistributed residual stress and stress intensity factor due to crack propagation were analyzed as changes of structural shape. Stress intensity factor was also calculated by using the 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. And it was validated that both the inherent strain analysis and the influence function method were efficient for analyzing stress intensity factor in residual stress fields caused by welding.溶接残留応力のある応力拡大係数は，影響関数法と固有ひずみ解析法で求めるができる．き裂進展解析の結果と疲労試験の結果と比較することにより影響関数法と固有ひずみ解析法の妥当性を評価する