Three-Dimensional Analysis of Crack Driving Force in Simulated Weld Residual Stress Fields

摘要

Recent attention has focused on the applicability of using load-controlled crack driving force solutions in fitness-for-service (FFS) assessments of flaws subject to weld residual stresses. To help facilitate increased understanding, three-dimensional (3D) weld residual stress (WRS) finite element simulation using the current state of the art and 3D explicit flaw modeling considering the WRS as an initial stress in the J-integral are performed for a simple plate. Stress redistribution and crack driving force are quantitatively characterized over a flaw range of 0.1 < a/t < 0.75. A discussion of crack driving force, including comparison of contour integral and crack tip opening displacement (CTOD) methods, is also made. Results show that stress redistribution/relaxation is not present for smaller flaw ratios, where numerical results compare well with standard load-controlled stress intensity factor solutions. Recommendations for further work are also presented.