Research On Residual Strength And Failure Probability Of High Strength X100 Containing Corrosion Defects

The pipeline is an important lifeline in the system and the most important and effective way to transport oil and gas.High-grade steel and large-diameter pipelines are the main development trend of my country's natural gas pipelines.Among them,the SinoRussian Eastern Route is a major project of great strategic significance in my country.By carrying out the analysis of the remaining strength and failure probability of high-grade steel and large-diameter pipelines,it is possible to better judge the pipeline's operating conditions,and to prevent the Sino-Russian east line pipeline from happening after several years of operation.The safety issues during the operation of the pipeline provide theoretical basis for the smooth service and maintenance of the pipeline.The main research content is the study of the remaining strength,failure probability,remaining life,and the number of failures of high-steel X100 pipelines.By investigating the research status of residual strength,failure probability,residual life and fault tree at home and abroad,formulate the research technical route of this article;Use Abaqus finite element software to establish a nonlinear model,and study the influence of different parameters on the residual strength of the X100 pipeline based on the control variable method;Using Matlab software to compile related programs,based on the iterative idea,study the influence of corrosion defect depth,length and corresponding standard deviation on pipeline failure probability;By establishing the fault tree of natural gas pipelines with corrosion defects,the minimum cut set of the pipeline with corrosion defects is calculated,and then the minimum cut set is obtained to calculate the structural importance of each factor.The results show that the depth of corrosion defects in either axial single-point corrosion or axial double-point corrosion has a particularly large impact on it.Like the law of single-point corrosion,the failure pressure decreases as the length of the axial double-point corrosion increases.,And the rate of reduction is not the same,and shows a decreasing trend;Within a certain range,the width of the axial double-point corrosion has a far greater influence on the failure pressure than the single-point corrosion defect,and cannot be ignored;When the distance between the axial double pitting corrosion increases until the failure pressure is consistent with the failure pressure of the single corrosion,the corrosion distance at this time has no effect on the result,and the defect depth,the internal pressure of the pipeline,and the wall are treated as two single corrosions.Thick and radial corrosion rates have a greater impact on the failure probability of X100 high-grade steel pipelines with defects.Based on the relevant content studied above,the corresponding prevention and control measures are proposed to ensure the safe operation of the pipeline during the service period.Provide a theoretical reference for the design of high-grade steel pipeline engineering in the future.