After that , we make with CDF drawing by interrelated formula and simulate the model of X56 pipeline with surface crack by finite element software ANSYS, then, we compute J integral of crack tip .

• R阻力曲线确定热影响区和焊缝金属分别具有的断裂韧度,根据相关的公式做出CDF评定图,应用有限元软件ANSYS模拟含表面裂纹的X56海底管线模型,并计算裂纹尖端的二维J积分值。