基于Monte-Carlo方法含缺陷管道失效概率计算方法研究

Failure probability calculation method of pipeline containing defects based on Monte-Carlo method

基于应力-强度干涉理论和概率R6失效计算方法,通过Monte-Carlo模拟方法建立管道缺陷特征参数与随机数的对应关系,并建立含缺陷管道的失效概率计算方法:针对表面半椭圆裂纹的管道失效形式,当Monte-Carlo模拟次数达到1000次时,其失效概率基本稳定,Pf=0.0015;应用敏感性分析理论,分析各随机参数的分散性(变异系数)对含缺陷埋地输油管道断裂失效概率的影响。结果表明:断裂韧性的变化对管道断裂失效概率的影响最大,通过敏感性分析发现,屈服强度的影响最小。

Based on the stress-strength interference theory and calculation method of probabilistic R6 failure,the Monte-Carlo simulationmethod was used to establish the relationship of random number and characteristic parameters of defects,and the failure probabilitycalculation method was put forward.Focusing on surface semi-elliptic crack,when simulation times of Monte-Carlo method reaches1000 times,the failure probability Pfbasically keeps constant,which is equal to 0.0015.Based on the theory of sensitivity analysis,the influence of the dispersion(variation coefficient)of random parameters on the fracture failure probability of buried oil pipelineswith defects was analyzed.The results show that the fracture toughness has the greatest influence on the fracture failure probability.At the same time,via sensitivity analysis,it can be seen that the influence of yield strength is the least.