论文部分内容阅读
钢制输气管道在制造、安装或运行过程中不可避免地会产生表面裂纹缺陷,这些表面裂纹在外力和腐蚀作用下发生扩展造成管道破裂失效,将严重影响高压天然气管道的安全运行,因此,开展了表面裂纹倾角对断裂参数影响规律的研究。采用ANSYS有限元模拟软件,建立了内压作用下含不同表面裂纹的管道的有限元模型,分析了不同倾角表面裂纹的J积分变化规律。研究表明:裂纹尖端J积分值随裂纹倾角近似呈余弦函数规律变化,在相同边界条件下,表面裂纹与管道轴向平行时,J积分值最大,此时表面裂纹最易发生扩展;表面裂纹与管道轴向垂直时,J积分值最小,此时表面裂纹发生扩展的可能性较小。
Steel gas pipelines inevitably generate surface crack defects during manufacture, installation or operation. These surface cracks expand due to external forces and corrosion and cause pipeline rupture failure, which will seriously affect the safe operation of high-pressure natural gas pipelines. Therefore, The influence of surface crack dip on fracture parameters has been studied. The finite element model of pipeline with different surface cracks under internal pressure was established by ANSYS finite element simulation software. The variation law of J integral of cracks with different inclination angles was analyzed. The results show that the J integral value of crack tip changes with the law of cosine function approximately as the crack dip angle. Under the same boundary condition, the J integral value is the maximum when the crack surface is parallel to the axial direction of the pipeline. At this time, the surface crack is most likely to expand. When the pipe is perpendicular to the pipe, the J integral value is the smallest, and the surface crack is less likely to expand at this time.