含腐蚀缺陷海底管道压溃压力计算方法

A method for calculating collapse pressure of submarine pipelines with corrosion defects

腐蚀是海底管道最常见的缺陷形式,明确腐蚀缺陷对海底管道压溃压力的影响规律,建立可靠的压溃压力计算方法对评估海底管道的安全运行具有重要意义。考虑几何非线性和材料非线性,建立了含腐蚀缺陷的海底管道数值仿真模型,通过与文献试验数据对比验证了其可靠性。在此基础上,开展了腐蚀参数敏感性分析,得到了腐蚀深度、长度和宽度对海底管道压溃压力的影响规律:腐蚀长度、宽度和深度对海底管道的压溃压力影响效果依次递增,相对于轴向短腐蚀管道,腐蚀深度和腐蚀宽度对长腐蚀管道压溃压力的影响更大。基于敏感性分析和大量数值计算结果,采用非线性回归方法得到了含腐蚀缺陷海底管道压溃压力的计算公式,将该公式计算结果与文献试验结果和现有方法计算结果进行了对比,本文回归公式与试验值的误差小于10%,与现有计算方法的误差小于3%,证明本文回归公式能较为准确地预测含腐蚀缺陷海底管道的压溃压力。相关成果为含腐蚀缺陷海底管道的完整性评价提供了参考。

Corrosion is the most common form of defects in submarine pipelines.It is important to reveal the influence law of corrosion defects on collapse pressure of the submarine pipelines and establish a reliable collapse pressure calculation method to evaluate the safe operation of submarine pipelines.Considering geometric nonlinearity and material nonlinearity,a numerical simulation model of submarine pipeline containing corrosion defects is established,and its reliability is verified by comparing with the test data in literature.On this basis,the sensitivity analysis of corrosion parameters is carried out,and the influence law of corrosion depth,length and width on the collapse pressure of submarine pipeline is obtained:i.e.,the influence of corrosion length,width and depth on the collapse pressure of submarine pipeline increases successively.Compared with the axial short corroded pipeline,the corrosion depth and width have a greater inference on the collapse pressure of long corroded pipeline.Based on the sensitivity analysis and a large number of numerical calculation results,the calculation formula of collapse pressure of submarine pipeline with corrosion defects is obtained by nonlinear regression method.The formula results are compared with the test results in literature and by existing method,the error between the regression formula and the test value in literature is less than 10%,and the error between the regression formula and the existing calculation method is less than 3%,which prove that the regression formula of this paper can predict the collapse pressure of submarine pipeline with corrosion defects more accurately.The study results of this paper provide a reference for the integrity evaluation of submarine pipelines with corrosion defects.