Abstract: Based on limited available fully plastic FEM solutions of J integral, a comprehensive and unified numerical solution is proposed. Various crack configurations and combined loads are taken into account in the present plastic solution of J integral. A technique to perform crack growth stability analysis for combined tension and bending load series is also presented in the paper. The G-Factor table for typical structural materials is established, which characterizes different fracture modes in defective pipes. The present work will provide important guideline in the actual application of the LBB assessmeflt technology.