Numerical assessment of cyclic J-integral ΔJ for predicting fatigue crack growth rate

The cyclic J-integral is a significant mechanical parameter to describe the elastic-plastic fatigue crack growth rate. A equivalent domain integral method based on finite element method was proposed for evaluating the cyclic J-integral. This numerical method was verified by comparing the results of cyclic J-integral with J-integral evaluated by using the built-in functionality of ABAQUS under monotonic tensile load. Base on this numerical method, the uniqueness of extreme value of cyclic J-integral was studied through a kinked crack and a specific code was also developed to simulate the crack propagation in 304 stainless steel (304SS) compact tension (CT) specimen under mode I loading. The expression of crack growth rate was established based on the cyclic J-integral obtained by the specific code and this expression is found to be in good agreement with the experimental results. The research contents in this paper may contribute to the damage tolerance assessment of components.