Abstract: Crack was one of the most dangerous pressure piping flaws. Beyond that, it was the main cause of pressure pipeline accidents. Based on related concepts of fracture mechanics, the 3-D models of pressure pipeline subjected to internal pressure and its surface oblique cracks under different Angles were established according to the ANSYS finite element software. In addition to that, the stress intensity factor of crack tip was calculated and analyzed by the finite element and the change rules between the stress intensity factor and crack Angles were concluded. According to that, the crack tip stress field strength was analyzed quantitatively. At the same time, it also provided some data supports for the study of inclined crack on the surface of pressure pipeline.

Key words: Pressure pipe, Oblique crack, Finite element, Stress intensity factor

摘要： 裂纹是压力管道最危险的一种缺陷，是导致压力管道各种事故的主要原因。因此，依据断裂力学的相关概念，运用ANSYS有限元软件，建立了受内压作用的压力管道及其表面具有不同周向夹角的斜裂纹的三维模型，并对裂纹尖端的应力强度因子进行有限元计算及分析，得出了裂纹的应力强度因子随裂纹角度的变化而变化的规律。定量分析了裂纹尖端应力场的强弱，为压力管道表面斜裂纹的研究提供了一定的数据支持。

关键词: 压力管道, 斜裂纹, 有限元, 应力强度因子