含表面裂纹X80管道的失效控制参量及计算

Failure Control Parameters and Calculation of X80 Pipeline with Surface Crack

采用有限元(FEA)方法对高屈强比X80管线管在含表面裂纹情况下的服役行为进行了模拟分析。计算结果表明,表面轴向裂纹的存在使得钢管环向变形急剧增加,且裂纹尺寸越大,影响效果越明显。材料的失效取决于环向变形与裂纹尖端J积分两个影响参量的竞争关系,通过绘制该两个影响参量之间的竞争图谱可以把服役过程分为三个区域,分别是安全区域、J积分控制失效区域和环向变形控制失效区域。该失效图谱对于深入理解X80管线管在实际服役下的失效行为及其控制参量将具有借鉴作用。

In this article, the service behaviors of high yield ratio X80 line pipe with surface crack were simulated by adopting FEA. The calculation results indicated that the axial cracks make toroidal deformation greatly increase. Further, the bigger crack size is the greater influence effect is. The failure of material depends on the competition relationship between the circumferential deformation and J integral ahead of the crack. The competition diagram of the above two parameters can divide the service process into three regions, including safety region, J integrate control failure region and circumferential deformation control failure region. This competition diagram will provide reference for deep understanding the failure behaviors of X80 line pipe under practical service conditions as well as its control measurements.