管道内表面裂纹角度对裂纹扩展的影响分析

Effect of Inner-surface Crack Angle of Pipeline on Crack Propagation

压力管道内表面裂纹的扩展是管道断裂失效的主要形式之一。以AP1000型核电站一回路主管道为例,利用扩展有限元法（XFEM）建立了内压作用下的管道内表面裂纹扩展模型,分析了不同角度内表面裂纹的扩展情况。结果显示,裂纹扩展速率与内表面裂纹和管道轴线方向的夹角有很大的关系,夹角在30°～60°间更易形成穿透裂纹。

The crack propagation in the inner surface of the pressure pipe is one of the main forms of pipe fracture failure. Taking the primary circuit main pipeline of AP 1000 nuclear power station as an example, the crack propagation model of the inner surface of the pipe was established by XFEM model. The propagation situation of the inner surface crack from different angles was analyzed. The results show that the crack growth rate has a close relationship with the angle between inner surface crack and axial direction of the pipe, and the penetrated crack is more easily formed at an angle between 30° to 60°