在役油气管道管体凹陷深度检测数据差异性原因分析
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摘要
在实际工程检测中,发现油气管道管体凹陷内检测数据与开挖后测量数据间有时存在一定差异,这导致在决定该凹陷管体是否需要修复时存在争议。运用ABAQUS有限元软件,对X80、D 1 219 mm×18.4 mm管体凹陷形成、回弹进行了模拟,得到管道内压和约束状态对凹陷深度变化及应力应变的影响规律。研究表明:开挖检测过程中,由于凹陷的约束状态改变,在管道内压和凹陷残余应力的作用下,凹陷会产生一定量的回弹;对于约束型凹陷,管体凹陷内检测深度与开挖检测深度差值很大;对于非约束凹陷,由于土壤对凹陷的约束作用有限,管体凹陷内检测深度与开挖检测深度差值较小。
In practical engineering detection, the difference between the detection and excavation results for pipeline internal dents is often existed,which causes the dispute on pipeline repair. By using the finite element method, the dynamic/static elastoplastic finite element model is established by ABAQUS. The formation and rebound of D 1 219 mm×18.4 mm X80 pipeline dent are simulated,and the influence of internal pressure and constraint state on the depth variation and stress-strain of the pipeline is analyzed. Research shows that during excavation testing,because of the change of the restraint state of the dent,the dent produces a certain amount of springback under the actions of the internal pressure of the pipeline and the residual stress of the dent; The difference between the detection and excavation results for the constraint type dent depth is greater; But the difference is smaller for the unconstraint type dent depth due to limit constraint action of soil.
In practical engineering detection, the difference between the detection and excavation results for pipeline internal dents is often existed,which causes the dispute on pipeline repair. By using the finite element method, the dynamic/static elastoplastic finite element model is established by ABAQUS. The formation and rebound of D 1 219 mm×18.4 mm X80 pipeline dent are simulated,and the influence of internal pressure and constraint state on the depth variation and stress-strain of the pipeline is analyzed. Research shows that during excavation testing,because of the change of the restraint state of the dent,the dent produces a certain amount of springback under the actions of the internal pressure of the pipeline and the residual stress of the dent; The difference between the detection and excavation results for the constraint type dent depth is greater; But the difference is smaller for the unconstraint type dent depth due to limit constraint action of soil.
引文
[1] COSHAM A,HOPKINS P. The effect of dents in pipelines—Guidance in the pipeline defect assessment manual[J].International Journal of Pressure Vessels and Piping,2004,81(2):127-139.
[2] RICK W,RICHARD K. Study of a plastic strain limit damage criterion for pipeline mechanical damage using FEA and full-scale denting tests[C]//Proceedings of the 2016 11th International Pipeline Conference. Calgary,Alberta:IPC,2016:IPC 64548.
[3] HANIF W,KENNY S. Mechanical damage and fatigue assessment of dented pipelines using FEA[C]//Proceedings of the 2014 10th International Pipeline Conference.Calgary,Alberta:IPC,2014:IPC33445.
[4] DAWSON S J,RUSSELL A,PATTERSON A. Emerging techniques for enhanced assessment and analysis of dents[C]//2006 International Pipeline Conference.Calgary,Alberta:IPC,2006:IPC10264.
[5]焦中良,帅健.含凹陷管道的完整性评价[J].西南石油大学学报(自然科学版),2011,33(4):157-164.
[6]祝悫智,吴超,李秋扬,等.全球油气管道发展现状及未来趋势[J].油气储运,2017,36(4):375-380.
[7] ASME B31.4-2014,Pipeline transportation systems for liquids and slurries[S].
[8] ASME B31.8-2014,Gas transmission and distribution piping systems[S].
[9]曾攀.有限元分析及应用[M].北京:清华大学出版社,2004.
[10]庄卓. ABAQUS非线性有限元分析与实例[M].北京:科学出版社,2005.
[11] WILLIAM D. CALLISTER Jr. Fundamentals of materials science and engineering[M].Hoboken,New Jersey:Wiley,2005:160-168.
[12] API PUBL 1156-1997,Effects of smooth and rock dents on liquid petroleum pipelines(phase II),first edition[S].
[2] RICK W,RICHARD K. Study of a plastic strain limit damage criterion for pipeline mechanical damage using FEA and full-scale denting tests[C]//Proceedings of the 2016 11th International Pipeline Conference. Calgary,Alberta:IPC,2016:IPC 64548.
[3] HANIF W,KENNY S. Mechanical damage and fatigue assessment of dented pipelines using FEA[C]//Proceedings of the 2014 10th International Pipeline Conference.Calgary,Alberta:IPC,2014:IPC33445.
[4] DAWSON S J,RUSSELL A,PATTERSON A. Emerging techniques for enhanced assessment and analysis of dents[C]//2006 International Pipeline Conference.Calgary,Alberta:IPC,2006:IPC10264.
[5]焦中良,帅健.含凹陷管道的完整性评价[J].西南石油大学学报(自然科学版),2011,33(4):157-164.
[6]祝悫智,吴超,李秋扬,等.全球油气管道发展现状及未来趋势[J].油气储运,2017,36(4):375-380.
[7] ASME B31.4-2014,Pipeline transportation systems for liquids and slurries[S].
[8] ASME B31.8-2014,Gas transmission and distribution piping systems[S].
[9]曾攀.有限元分析及应用[M].北京:清华大学出版社,2004.
[10]庄卓. ABAQUS非线性有限元分析与实例[M].北京:科学出版社,2005.
[11] WILLIAM D. CALLISTER Jr. Fundamentals of materials science and engineering[M].Hoboken,New Jersey:Wiley,2005:160-168.
[12] API PUBL 1156-1997,Effects of smooth and rock dents on liquid petroleum pipelines(phase II),first edition[S].