ON THE COMPUTATION OF MIXED-MODE K-FACTORS FOR A DYNAMICALLY PROPAGATING CRACK, USING PATH-INDEPENDENT INTEGRALS J'K

The path-independent integral J prime //k is used to numerically obtain the mixed-mode dynamic stress-intensity factors for a crack propagating in a prescribed direction with a prescribed velocity. Moving isoparametric (non-singular) elements are used to model crack propagation. The desirability of using specific coordinate systems to improve the accuracies of the numerical solutions for K-factors is pointed out. Two procedures for extracting the mixed-mode K-factors from the J prime integral for a propagating crack are given. It is found that the component of J prime along the crack-axis, i. e. J//1 prime **0, is always equal to or greater than the product of a crack-velocity-function and the component normal to the crack-axis, J//2 prime **0.