Abstract: The assessment of failure probability for an oil pipeline containing cracks is made in order to assure safety of the pipeline.The probabilistic characteristics of the structural and mechanical parameters of the pipeline are reasonably determined by means of statistical analysis on these parameters.For the surface semi-elliptical crack existing in pipe,some limit state function expressions about pipeline fracture failure are established with the failure assessment diagram technique.The failure probability is solved by Monte-Carlo simulation.The random distribution of the assessment points in failure assessment diagram for oil pipeline is directly demonstrated with random sampling computation.Then failure probabilities of the pipe body and weld seams are determined,and the sensitive factors to failure probability are illustrated.The method presented above can be used in safety assessment of oil and gas pipelines and has a certain reference value in engineering practice.

Key words: oil pipeline, statistical analysis, crack, failure probability, safety assessment, state function

摘要： 为了确保管道的结构完整性,对一条含裂纹输油管道的失效概率进行了评定.分析了这条输油管道的主要结构与力学参数,确定了这些参数的概率特征.对管道上的表面半椭圆裂纹,利用失效评定图方法建立了管道断裂失效的极限状态函数,用Monte Carlo模拟方法求解失效概率.通过随机抽样计算,在失效评定图上直观地显示了评定点的随机分布情况,得到了管道母材和焊缝的失效概率,并表明了影响失效概率的敏感性因素.所提出的方法适用于油气管道的安全评定,具有工程实用价值.

关键词: 输油管道, 裂纹, 失效概率, 统计分析, 安全评定, 状态函数