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为评估含腐蚀缺陷的凹陷压力管道的安全性,用有限元弹塑性分析法,建立管道数值计算模型。研究管道缺陷长度、深度、宽度、压头直径、下压深度和初始内压等敏感性参数对含腐蚀凹陷管道极限载荷的影响。基于PCORRC法,推导多因素失效评价公式基本形式。用非线性回归分析法,拟合公式中的待定系数。结果表明,除缺陷宽度外,其余因素对极限内压影响较大;随缺陷深度、下压深度和初始内压的增大,极限内压均呈减小趋势;压头尺寸与缺陷长度相对大小不同,极限内压变化规律存在差异;失效评价公式计算值与数值模拟结果吻合度较高,相对误差较小。
In order to evaluate the safety of the depressed pressure pipeline with corrosion defects, a numerical model of the pipeline was established by using finite element elasto-plastic analysis method. The effects of the length, depth, width, head diameter, depth of depression and initial pressure on the ultimate load of pipeline with corrosion pitting were investigated. Based on the PCORRC method, the basic form of multi-factor failure evaluation formula is deduced. Non-linear regression analysis is used to fit the undetermined coefficients in the formula. The results show that, except for the width of defect, the other factors have a great influence on the ultimate internal pressure. With the increase of defect depth, depressing depth and initial internal pressure, the ultimate internal pressure decreases. The size of the indenter relative to the length of the defect Different, the law of variation of the limit internal pressure is different; the calculated value of the failure evaluation formula is in good agreement with the numerical simulation result, and the relative error is small.