基于3D-VCCT的多裂纹输气管道断裂分析方法
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摘要
现行的国家标准因不能准确反映含缺陷输气管道多裂纹干涉效应,从而使得评定结果偏于保守。为了提高含缺陷输气管道安全评估的准确性,在对比奇异单元法和三维虚拟裂纹闭合技术(Three-Dimensional Virtual Crack Closure Technology,3D-VCCT)的基础上,优选3D-VCCT建立输气管道多裂纹干涉模型,并通过分析裂纹相互干涉作用因子的变化,研究了附属裂纹对主裂纹前缘各点的干涉影响。研究结果表明:①随附属裂纹尺寸的变化,平行共线裂纹的最强干涉效应发生在裂纹近表面点并表现为增强效应;②一定条件下,平行共轴裂纹的干涉效应在裂纹最深点和表面点较为显著,并且最深点表现为增强效应,而表面点则表现为减弱效应;③当裂纹间的水平间距大于主裂纹长半轴的6倍时,平行共线裂纹与平行偏置裂纹的干涉效应微乎其微,可将多裂纹简化为单裂纹进行分析。结论认为,该研究成果不仅可以为多裂纹输气管道的断裂分析提供技术参考,而且还可以为输气管道多裂纹的安全评定提供理论依据。
The current national criteria with more conservative evaluation results can not accurately reflect the interference effect of multiple cracks on the safety assessment of gas line pipes. In view of this, we compared the singular element method with the three-dimensional virtual crack closure technology(3D-VCCT). Based on this, the 3D-VCCT was selected to establish a multi-crack interference model of gas line pipes. Finally, the interference effect of subsidiary cracks on the front points of the main crack was studied by analyzing the variation of the interference factors between cracks. And the following research results were obtained. First, as the subsidiary crack size changes, the strongest interference effect of a parallel collinear crack occurs near the surface and manifests as enhancement effect.Second, under certain conditions, the interference effect of a parallel collinear crack is more significant at the deepest point and the surface point of the crack, and it presents as an enhancement effect at the deepest point and as a weakening effect at the surface point. Third,when the horizontal spacing between cracks is greater than 6 times of the long half axis of the main crack, the interference effect between the parallel collinear crack and the parallel offset crack is negligible, and multiple cracks can be simplified as a single crack in the process of analysis. This research can provide a technical reference for fracture analysis on multi-crack gas line pipes and the theoretical basis for their safety assessment.
The current national criteria with more conservative evaluation results can not accurately reflect the interference effect of multiple cracks on the safety assessment of gas line pipes. In view of this, we compared the singular element method with the three-dimensional virtual crack closure technology(3D-VCCT). Based on this, the 3D-VCCT was selected to establish a multi-crack interference model of gas line pipes. Finally, the interference effect of subsidiary cracks on the front points of the main crack was studied by analyzing the variation of the interference factors between cracks. And the following research results were obtained. First, as the subsidiary crack size changes, the strongest interference effect of a parallel collinear crack occurs near the surface and manifests as enhancement effect.Second, under certain conditions, the interference effect of a parallel collinear crack is more significant at the deepest point and the surface point of the crack, and it presents as an enhancement effect at the deepest point and as a weakening effect at the surface point. Third,when the horizontal spacing between cracks is greater than 6 times of the long half axis of the main crack, the interference effect between the parallel collinear crack and the parallel offset crack is negligible, and multiple cracks can be simplified as a single crack in the process of analysis. This research can provide a technical reference for fracture analysis on multi-crack gas line pipes and the theoretical basis for their safety assessment.
引文
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[3]Kumar SS,Murugan M,Kalimuthu S&Balaji N.Mixed mode stress intensity factor determination of multiple cracks in hollow circular pipe[J].Journal of Failure Analysis&Prevention,2016,16(4):1-7.
[4]Jacquemin T,Kartal ME,Suau GD&Hertz-Clemens S.Contribution of finite element analyses to crack-like flaw assessments in a gas pipeline[J].International Journal of Pressure Vessels&Piping,2018,161(3):41-49.
[5]Arafah D,Madia M,Zerbst U,Beretta S&Cristea ME.Instability analysis of pressurized pipes with longitudinal surface cracks[J].International Journal of Pressure Vessels&Piping,2015,127(3):48-57.
[6]宋汉成,张海亮,王学力,冯庆善,林逸汉.基于应力投影的油气管道螺旋裂纹评估方法[J].天然气工业,2012,32(4):79-82.Song Hancheng,Zhang Hailiang,Wang Xueli,Feng Qingshan&Lin Yihan.Assessment methods of oil&gas pipeline screwy cracks based on stress projection[J].Natural Gas Industry,2012,32(4):79-82.
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[8]何雪,秦晓峰,谢里阳,钱文学.管道轴向双裂纹夹角对尖端应力强度因子的影响[J].东北大学学报(自然科学版),2011,32(11):1623-1626.He Xue,Qin Xiaofeng,Xie Liyang&Qian Wenxue.Influence of double axial cracks'angle on stress intensity factors of crack tip[J].Journal of Northeastern University(Natural Science Edition),2011,32(11):1623-1626.
[9]王元清,廖小伟,周晖,石永久,陈建陵,叶国平.基于SIN-TAP-FAD方法的含裂纹缺陷钢结构构件安全性评定研究[J].工程力学,2017,34(5):42-51.Wang Yuanqing,Liao Xiaowei,Zhou Hui,Shi Yongjiu,Chen Jianling&Ye Guoping.Safety assessment of steel structure component with crack defects using SINTAP FAD method[J].Engineering Mechanics,2017,34(5):42-51.
[10]Kumar SS,Murugan M&Kailmuthu S.Mixed mode stress intensity factor determination of multiple cracks in hollow circular pipe[J].Journal of Failure Analysis and Prevention,2016,16(4):555-561.
[11]Irwin GR.Plastic zone near a crack tip and fracture toughness[C].New York:Proceedings of the Seventh Sagamore Ordnance Material Conference,1960.
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[13]Fawaz SA.Application of the virtual crack closure technique to calculate stress intensity factors for through cracks with an elliptical crack front[J].Engineering Fracture Mechanics,1996,59(3):327-342.
[14]Henshell RD&Shaw KG.Crack tip finite elements are unnecessary[J].International Journal for Numerical Methods in Engineering,2010,9(3):495-507.
[15]Shih CF,Lorenzi HGD&German MD.Crack extension modeling with singular quadratic isoparametric elements[J].International Journal of Fracture,1976,12(4):647-651.
[16]姚安林,徐涛龙,郑健,曾祥国,陈华燕.河流穿越高压输气管道临界悬空长度的数值模拟研究[J].工程力学,2013,30(3):152-158.Yao Anlin,Xu Taolong,Zheng Jian,Zeng Xiangguo&Chen Huayan.Study on numerical simulation of critical suspended length of high-pressure gas pipeline crossing riverbed[J].Engineering Mechanics,2013,30(3):152-158.
[17]齐桂营.具有倾斜裂纹的CTS试样三维断裂行为研究[D].哈尔滨:哈尔滨工程大学,2011.Qi Guiying.3-D fracture behavior of CTS specimens with inclined cracks[D].Harbin:Harbin Engineering University,2011.
[18]中国航空研究院.应力强度因子手册[M].增订版.北京:科学出版社,1993.Chinese Aeronautical Establishment.Stress intensity factor handbook[M].Revised edition.Beijing:Science Press,1993.
[2]刘晓宇.关于裂纹安全评定及TOFD检测标准的研究[D].北京:北京化工大学,2012.Liu Xiaoyu.Research on crack safety assessment and TOFD testing standards[D].Beijing:Beijing University of Chemical Technology,2012.
[3]Kumar SS,Murugan M,Kalimuthu S&Balaji N.Mixed mode stress intensity factor determination of multiple cracks in hollow circular pipe[J].Journal of Failure Analysis&Prevention,2016,16(4):1-7.
[4]Jacquemin T,Kartal ME,Suau GD&Hertz-Clemens S.Contribution of finite element analyses to crack-like flaw assessments in a gas pipeline[J].International Journal of Pressure Vessels&Piping,2018,161(3):41-49.
[5]Arafah D,Madia M,Zerbst U,Beretta S&Cristea ME.Instability analysis of pressurized pipes with longitudinal surface cracks[J].International Journal of Pressure Vessels&Piping,2015,127(3):48-57.
[6]宋汉成,张海亮,王学力,冯庆善,林逸汉.基于应力投影的油气管道螺旋裂纹评估方法[J].天然气工业,2012,32(4):79-82.Song Hancheng,Zhang Hailiang,Wang Xueli,Feng Qingshan&Lin Yihan.Assessment methods of oil&gas pipeline screwy cracks based on stress projection[J].Natural Gas Industry,2012,32(4):79-82.
[7]白永强,帅健,许葵,孙亮,陈钢.输气管道裂纹动态扩展的影响因素分析[J].天然气工业,2006,26(5):122-124.Bai Yongqiang,Shuai Jian,Xu Kui,Sun Liang&Chen Gang.Determinants for crack dynamic propagation of gas transmission line[J].Natural Gas Industry,2006,26(5):122-124.
[8]何雪,秦晓峰,谢里阳,钱文学.管道轴向双裂纹夹角对尖端应力强度因子的影响[J].东北大学学报(自然科学版),2011,32(11):1623-1626.He Xue,Qin Xiaofeng,Xie Liyang&Qian Wenxue.Influence of double axial cracks'angle on stress intensity factors of crack tip[J].Journal of Northeastern University(Natural Science Edition),2011,32(11):1623-1626.
[9]王元清,廖小伟,周晖,石永久,陈建陵,叶国平.基于SIN-TAP-FAD方法的含裂纹缺陷钢结构构件安全性评定研究[J].工程力学,2017,34(5):42-51.Wang Yuanqing,Liao Xiaowei,Zhou Hui,Shi Yongjiu,Chen Jianling&Ye Guoping.Safety assessment of steel structure component with crack defects using SINTAP FAD method[J].Engineering Mechanics,2017,34(5):42-51.
[10]Kumar SS,Murugan M&Kailmuthu S.Mixed mode stress intensity factor determination of multiple cracks in hollow circular pipe[J].Journal of Failure Analysis and Prevention,2016,16(4):555-561.
[11]Irwin GR.Plastic zone near a crack tip and fracture toughness[C].New York:Proceedings of the Seventh Sagamore Ordnance Material Conference,1960.
[12]解德.断裂力学中的数值计算方法及工程应用[M].北京:科学出版社,2009.Xie De.Numerical calculation method and engineering application in fracture mechanics[M].Beijing:Science Press,2009.
[13]Fawaz SA.Application of the virtual crack closure technique to calculate stress intensity factors for through cracks with an elliptical crack front[J].Engineering Fracture Mechanics,1996,59(3):327-342.
[14]Henshell RD&Shaw KG.Crack tip finite elements are unnecessary[J].International Journal for Numerical Methods in Engineering,2010,9(3):495-507.
[15]Shih CF,Lorenzi HGD&German MD.Crack extension modeling with singular quadratic isoparametric elements[J].International Journal of Fracture,1976,12(4):647-651.
[16]姚安林,徐涛龙,郑健,曾祥国,陈华燕.河流穿越高压输气管道临界悬空长度的数值模拟研究[J].工程力学,2013,30(3):152-158.Yao Anlin,Xu Taolong,Zheng Jian,Zeng Xiangguo&Chen Huayan.Study on numerical simulation of critical suspended length of high-pressure gas pipeline crossing riverbed[J].Engineering Mechanics,2013,30(3):152-158.
[17]齐桂营.具有倾斜裂纹的CTS试样三维断裂行为研究[D].哈尔滨:哈尔滨工程大学,2011.Qi Guiying.3-D fracture behavior of CTS specimens with inclined cracks[D].Harbin:Harbin Engineering University,2011.
[18]中国航空研究院.应力强度因子手册[M].增订版.北京:科学出版社,1993.Chinese Aeronautical Establishment.Stress intensity factor handbook[M].Revised edition.Beijing:Science Press,1993.