Effects of residual stress distribution and geometry of components on stress intensity factor and crack growth behavior of surface crack. Evaluation of SCC growth under residual stress field. Report 2

Stress intensity factor estimated by using an appropriate modeling of components is essential for evaluation of crack growth behavior in stress corrosion cracking. For the appropriate modeling of welded components with a surface crack, it is important to understand the effects of residual stress distribution and the geometry of component on the stress intensity factor of the crack. In this study, stress intensity factors of surface crack under two assumed residual stress fields were calculated. As the residual stress fields, bending type stress field (tension-compression) and self-equilibrating stress field (tension-compression-tension) through the thickness were assumed. The geometries of welded components were set to plate and piping. The assumed surface cracks for evaluations were long crack in the surface direction and semi-elliptical surface crack. Furthermore, the crack growth evaluations were conducted to understand the effects of residual stress distribution and the geometry of component. From the comparison of stress intensity factors and crack growth evaluation for surface crack under residual stress fields, the effects of residual stress distribution and the geometry of component on the stress intensity factor of surface crack and on the appropriate modeling of cracked components were discussed. (author)