基于ANSYS有限元法的外腐蚀管道剩余强度和剩余寿命的研究

Study on Residual Strength and Remaining Life of Externally-corroded Pipelines Based on Finite Element Analysis

采用ANSYS有限元软件,结合大庆油田采油六厂埋地管道的实际工况,对含外腐蚀缺陷的管道进行了分析,研究了不同形状下缺陷长度、宽度及深度等因素对管道失效的影响,以管道实测缺陷为依据,用ANSYS计算了管道的剩余强度,根据失效准则并结合实测数据,确定了腐蚀管道的剩余寿命。结果表明:对于平底方形缺陷,缺陷长度和深度对失效的影响都有临界值,深度是影响失效的一个重要因素;对于椭圆形缺陷来说,缺陷长度和深度对失效的影响成正比,缺陷宽度对失效的影响成反比关系。ANSYS有限元法为寿命预测提供了必要的保障,对工程应用有重要的参考价值。

Making use of ANSYS and having the actual condition of buried pipelines in oilfield considered,the pipeline with external corrosion defect was analyzed,including the influence of defect length with different shapes,width and depth on the pipeline failure.Based on actually-measured defect of the pipeline and the failure criterion,the pipeline residual strength was calculated with ANSYS and its residual life was determined.The results show that,for the flat square defect,the influence of both defect length and depth on the pipeline failure has a critical value,and the defect depth is one of the important factors that greatly influences the pipeline life; and for elliptic defects,both defect length and depth are in direct proportion to the failure influence,and the defect width is in inverse proportion to the failure influence.The finite element method can provide the safeguard for remaining life prediction and it has reference value in engineering application.