管道表面焊缝裂纹尖端应力强度因子的数值模拟研究

Numerical Simulation Analysis of Stress Intensity Factor at Tip of Welding Crack on Pipeline Surface

研究了管道表面焊缝裂纹尖端应力强度因子的数值模拟方法。首先利用有限元软件分析一算例，结果和解析解吻合，说明了本文所建模型的合理性。给出了内压作用下轴向表面焊缝裂纹和弯距作用下环向表面焊缝裂纹尖端的张开型应力强度应力因子。以上数值分析给出了焊缝裂纹尖端应力强度因子计算的一般性规律，可以指导不同焊缝裂纹，管道和载荷情况下的应力强度因子计算，为含焊缝裂纹管道的安全评估提供支持。

Welding crack has seriously affected the operation safety of offshore pipeline, and the stress intensity factor （SIF） is an important criterion which is applied＇ to estimating the crack propagation. In this paper the analysis of SIF at tip of pipeline surface ci＇ack is performed with the numerical simulation method （NSM）. Firstly an example which has analytical solution is calculated by NSM, and the comparison between the result of NSM and analytical solution shows that the NSM applied in this paper is effective. Then the SIF of axial surface crack subjected to internal pressure and circular surface crack subjected to bending load are analyzed. The foregoing calculations give the general laws in the analysis of SIF, which can be used to guide the SIF analysis of varying crack type, pipeline and loading. The NSM applied in this paper can provide the support to the safety assessment of pipeline where the welding crack exists.