【摘要】 为研究表面环向裂纹缺陷对管道的影响，基于扩展有限元法(XFEM),运用有限元软件ABAQUS,针对含环向圆形表面裂纹的X60钢管道的裂纹扩展规律进行了数值模拟研究，并探讨了裂纹所处位置、内压以及裂纹初始大小不同的情况下对表面裂纹环向扩展的影响，对仅在内压作用下含裂纹缺陷管道的最大应力、管道裂纹扩展启裂及穿透时的拉伸位移进行分析。结果表明：管道所受最大应力处于裂纹尖端位置，裂纹扩展后该处应力有所下降；仅在内压作用下，内压越大则含环向裂纹管道的最大应力呈线性增长，裂纹初始大小及裂纹所处位置对仅内压条件下含环向裂纹管道的最大应力的影响较小；在轴向位移作用下，裂纹初始大小对裂纹扩展时的位移有显著影响，裂纹启裂及穿透管壁时管道的轴向位移随裂纹增大而迅速下降，裂纹在一定大小范围内，内壁裂纹启裂及穿透管壁时的管道轴向位移小于外壁裂纹，此时内壁裂纹更为危险，当裂纹增大至一定程度后，外壁裂纹更危险。更多还原

【Abstract】 In order to study the influence of surface circumferential crack defects on pipelines, based on the extended finite element method(XFEM), a numerical simulation study was carried out on the crack propagation law of the X60 steel pipeline with circumferential circular surface cracks using the finite element software ABAQUS. Furthermore, the effects of crack location, internal pressure and initial crack size on the circumferential propagation of surface crack were discussed, and the maximum stress of the pipeline with cracked defects only under the action of internal pressure as well as the tensile displacement of the pipeline when the crack expands and penetrates the pipeline wall were analyzed. Results showed that the maximum stress on the pipeline was at the tip of the crack, and the stress there decreased after the crack expanded. When only under the action of internal pressure, the maximum stress of the pipe with circumferential cracks increased linearly with the rising of internal pressure, and the initial size and location of the crack had little effect on the maximum stress of the pipeline with circumferential cracks. Under the effect of axial displacement, the initial size of the crack had a significant influence on the displacement when the crack propagated. The axial displacement of the pipeline when the crack expands and penetrates the pipeline wall decreased rapidly with the rising of the crack size. When the crack size was in a certain range, the axial displacement of the pipeline when the inner wall crack expands and penetrates the pipe wall was smaller than the outer wall crack, which indicated that the crack on the inner wall was more dangerous. After the cracks increased to a certain size, the outer wall cracks became more dangerous.更多还原