大型压力管道焊接缺陷的强度分析与安全评定
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摘要
如今,压力管道被广泛应用在石油化工、冶金、电力和医药等行业,同时也向大型化、多样化、复杂化发展。但是如何处理带有缺陷的压力管道,是目前工程界所关注的问题。
压力钢管是一种大型压力管道,它是水电工程中输水建筑物的重要组成部分,它承受着较大的内水压力以及自身的重量和水重。压力钢管在生产和安装过程中,容易产生焊接缺陷。这些缺陷一般可以通过补焊等措施进行修复,但是较小的缺陷往往被忽略,而没有引起重视。在这些缺陷处,接头承载截面的几何尺寸发生了突变,产生了较强的应力集中,大大降低了接头的承载能力,对结构的静载强度、疲劳强度、脆性断裂以及抗应力腐蚀开裂都有重大的影响。因此,有必要对含焊接缺陷的压力钢管进行力学分析和安全评定。
咬边和错边都是压力钢管生产和安装过程中常见的焊接缺陷,它们不能用常规的方法进行应力分析。因此,本论文根据某水电站实例,建立咬边和错边的三维有限元模型,并通过有限元分析软件ANSYS9.0,对在不同深度、不同锐度和不同位置条件下的咬边和错边进行了应力计算和分析,并讨论了不同条件下的咬边和错边对焊接接头应力集中的影响。
本文还按照“压力容器缺陷评定规范”CVDA-84和“在用含缺陷压力容器安全评定”标准的规定,对纵缝不同深度咬边缺陷进行了安全评定,并给出了最大允许咬边深度,为咬边缺陷的返修和处理提供了可靠的力学依据,有极大的工程意义。
Now, pressure piping is extensively used in petrochemical、metallurgy、electric power、medicine and so on. It is also developing with large-scale、diversification、and complication. But how to deal with the pressure pipings with defects is an important question in project area.
Penstock is a kind of large pressure piping and is an important constitute of the building of power plant with water-transportation. It takes on bigger inner hydraulic pressure, the weight of itself and the watery weight. During the manufacture and fixing of penstock, it is easily to get welding defects and can be repaired by repair welding, but some shallow defects are usually neglected and don't bring the recognition. Where the defects are, the size of received section could be changed. It results in bigger stress concentration, mostly reduces the bearing power of the welded joint and has an important impact on the static strength, the fatigue strength, the brittle fracture and the resistance to stress erode cracking. So it is necessary to finish the mechanics analysis and safety assessment of the penstocks with welding defects.
Undercut and unfitness are common welding defects in the producing and fixing of penstocks. They are hard to be analyzed by using general methods. In this paper, based on the fact of hydroelectric power station, three-dimensional finite element models of undercut and unfitness are built. And the finite element software ANSYS 9.0 would be used to have a stress account and analysis on the undercut and unfitness with different depth, sharpness, and place. Secondly the affection of the defects in different conditions at the welded joint with stress concentration is discussed.
By using CVDA-84 and "Safety assessment for in-service pressure vessels containing defects", this paper makes safety assessment about the penstocks with longitudinal undercut of different depth and works out the largest depth of undercut allowed. It has large significance for engineering.
压力钢管是一种大型压力管道,它是水电工程中输水建筑物的重要组成部分,它承受着较大的内水压力以及自身的重量和水重。压力钢管在生产和安装过程中,容易产生焊接缺陷。这些缺陷一般可以通过补焊等措施进行修复,但是较小的缺陷往往被忽略,而没有引起重视。在这些缺陷处,接头承载截面的几何尺寸发生了突变,产生了较强的应力集中,大大降低了接头的承载能力,对结构的静载强度、疲劳强度、脆性断裂以及抗应力腐蚀开裂都有重大的影响。因此,有必要对含焊接缺陷的压力钢管进行力学分析和安全评定。
咬边和错边都是压力钢管生产和安装过程中常见的焊接缺陷,它们不能用常规的方法进行应力分析。因此,本论文根据某水电站实例,建立咬边和错边的三维有限元模型,并通过有限元分析软件ANSYS9.0,对在不同深度、不同锐度和不同位置条件下的咬边和错边进行了应力计算和分析,并讨论了不同条件下的咬边和错边对焊接接头应力集中的影响。
本文还按照“压力容器缺陷评定规范”CVDA-84和“在用含缺陷压力容器安全评定”标准的规定,对纵缝不同深度咬边缺陷进行了安全评定,并给出了最大允许咬边深度,为咬边缺陷的返修和处理提供了可靠的力学依据,有极大的工程意义。
Now, pressure piping is extensively used in petrochemical、metallurgy、electric power、medicine and so on. It is also developing with large-scale、diversification、and complication. But how to deal with the pressure pipings with defects is an important question in project area.
Penstock is a kind of large pressure piping and is an important constitute of the building of power plant with water-transportation. It takes on bigger inner hydraulic pressure, the weight of itself and the watery weight. During the manufacture and fixing of penstock, it is easily to get welding defects and can be repaired by repair welding, but some shallow defects are usually neglected and don't bring the recognition. Where the defects are, the size of received section could be changed. It results in bigger stress concentration, mostly reduces the bearing power of the welded joint and has an important impact on the static strength, the fatigue strength, the brittle fracture and the resistance to stress erode cracking. So it is necessary to finish the mechanics analysis and safety assessment of the penstocks with welding defects.
Undercut and unfitness are common welding defects in the producing and fixing of penstocks. They are hard to be analyzed by using general methods. In this paper, based on the fact of hydroelectric power station, three-dimensional finite element models of undercut and unfitness are built. And the finite element software ANSYS 9.0 would be used to have a stress account and analysis on the undercut and unfitness with different depth, sharpness, and place. Secondly the affection of the defects in different conditions at the welded joint with stress concentration is discussed.
By using CVDA-84 and "Safety assessment for in-service pressure vessels containing defects", this paper makes safety assessment about the penstocks with longitudinal undercut of different depth and works out the largest depth of undercut allowed. It has large significance for engineering.
引文
[1]李志安等编著.压力容器断裂理论与缺陷评定[M].大连理工大学出版社.1994.
[2]俞树容,王志文.压力容器安全评定的现代方法[J].化工机械1995,22(3):52-55
[3]Wilkowski G M,Others,Short Cracks in Piping and Piping Welds.Seminnual Reports by Battelle,NUREG/CR-4599,1991,1(1,2);1992,2(1,2);1993,3(1);1994,4(2),U.S.Nuclear Regulatory Commission Washington.D.C.
[4]ASME Nuclear Power Plants Components Code Nc-3658,ASME Section Ⅲ.
[5][美]库默等著,周洪范等译.弹塑性断裂分析工程方法(ERPI报告NP-1931)[M].国防工业出版社,1985.
[6]Wilkowski G M,Others.Degraded Piping Program Phase I Summary of Technical Results and Their Sinificance to Leak-Before-Break and in Service Flaw Acceptance Criteria,March 1984-Jannuary 1989.NUREG/CR-4082,Vol,8tU.S.Nuclear Regulatory Commision,Washington,D.C.March,1989.
[7]R.W.尼柯尔斯[英]主编,李建国等译.压力容器技术进展—5规范和标准.机械工业出版社,1992.
[8]Schulz.The Evalution of the Break Preclusion Concept for Nuclear Power Piant in Germany.Paper,4,Specialist Meeting on Leak Before Break in Reactor Piping and Vessels.Lyon,France,Oct,1995.
[9]李培宁等.国际压力容器缺陷工程评定技术进展[J].压力器,1991,8(2):3-6.
[10]沈士明.在役压力管道安全评定研究的现状与发展[J]中国机械工 程,1997,8(3):101-104.
[11]Hoppar AtMayfieldM,Olson R,et al,Overview of the IPING·I Program Seismic Loaded Creaked Piping System Experiments,SMIRT-13Conference,Parto Ahgre,Brazil,August,1995.
[12]钟群鹏等.中国压力容器安全评定技术的研究应用和发展[J].中国锅炉压力容器安全,1997,13(2):4-9.
[13]钟群鹏等.我国压力容器安全评定技术的现状和发展[J]中国机械工程,1997,8(5):95-100.
[14]压力容器缺陷评定规范编制组.压力容器缺陷评定规范CVDA-1984.
[15]中华人民共和国国家质量监督检验疫总局,中国国家标准化管理委员会.GB/T19624-2004在用含缺陷压力容器安全评定[S].北京:中国标准化出版社,2004.
[16]王文和,沈士明等.含缺陷压力管道安全评定方法研究的现状与发展.管道技术与设备,2007,(2).
[17]Rahman S,Brust F,Ghadiali N et al.Recent Evaluations of crack-Opening-Area in Circumferentiatly Cracked Pipes,Paper 24,3.Specialist Meeting on Leak Before Break in Reactor Piping and Vessels,Lyon,France,Oct,1995.
[18]Ktecker,R.,Brnst,F.,and Wilkowsk,G.M.NRC Leak Before Break (LBB·NRC)Analysis Method for Circumferentlally Through-Wall Cracked Pipes under Axial Plus Bending Loads.NUREG/CR-4572 May 1986.
[19]Metals Handbook,9~(th)ed.vol.11,Failure Analysis and Prevention,ASM,Ohio,1980.
[20]彭在美.国内钢管业的发展方向.管道技术与设备,2005(4):22-23.
[21]田锡唐.焊接结构[M].北京:机械工业出版社,1993.10.
[22]天津大学焊接教研室.金属熔焊原理及工艺[M].北京:机械工业出版社,1981.
[23]周振丰,张文钱.焊接冶金与金属焊接性[M].第2版.北京:机械工业出版社,1988.11
[24]姜换中.电弧焊与电渣焊[M].北京:机械工业出版社,1988.11.
[25]高勇,雷斌隆,高先安.断裂力学和有限元法在工程机械安全评定中的应用.矿山机械,2004(5).
[26]沈成康.断裂力学[M].同济大学出版社,1996:1-7
[27]戴振羽.断裂力学基础教程[M].西南交通大学出版社,2007:2-5.
[28]吴家龙.弹性力学[M].高等教育出版社,2001.
[29]丁桂宝等著.弹塑性力学[M].西南交通大学出版社,2006.
[30]霍立兴.焊接结构的断裂行为及评定[M].机械工业出版社,2000:149-241.
[31]沈士明,赵建平著.压力管道安全评定技术的进展.压力容器[J],2007:58-66.
[32]王志文,李培宁,琚定一等.压力容器断裂评定理论及规范的新发展.石油化工设备,1988,17(3):1-4.
[33]徐宏.压力管道缺陷评定工程方法.华东理工大学博士学位论文.1995.
[34]周剑秋,沈士明.失效评定图在含缺陷压力管道断裂评定中应用.化工机械,1997,24(2):16-29.
[35]王宗杰.焊接工程综合试验技术[M].机械工业出版社,1997.6.
[36]华东化工学院化机所译.有缺陷结构完整性的评定标准R/H/R6[S].第三版.化学工业部设备设计中心站,1998.
[37]李培宁.国外压容器和工业结构缺陷评定规范的新进展[R].华东理工大 学.
[38][美]库默等著,董亚民等译.弹塑性断裂分析进展(ERPI报告NP-3607)[M].清华大学工程力学研究所,1984.
[39]ERPI and Novelech Comporation.Ductile Fracture Handbook.Volumel(R),Research Reports Center Palo Alto.California.1991.
[40]SINrAP.Structure Integrity Assessment Procedure for Europe Industry Project BE 95-1426.Final Procedure[S],British Steel Report,Rotherham 1999.
[41]ASME B&PV Code N-480[S].Examination Requirements for Pipe Well Thinning Due to Single Phase Erosion and Corrosion,Section Ⅺ,Division 1,1990.
[42]李培宁.各国缺陷评定规范的发展.国家质量技术监督局锅炉压力容器检测中心网.
[43]王勖成.有限单元法[M].清华大学出版社,2005:5-8.
[44]朱伯芳.有限单元法原理和应用[M],第2版.中国水利电力出版社.1998.
[45]康国政编著.大型有限元程序的原理、结构与使用[M].西南交通大学出版社,2004.
[46]杜平安,甘娥忠,于亚婷编著.有限元法—原理、建模及应用[M].国防工业出版社,2004.
[47]余伟炜,高炳军等著.ANSYS在机械与化工装备中的应用[M]中国水利水电出版社.2006:1-3.
[48]博弈工作室.ANSYS9.0经典产品基础教程与实例详解[M].中国水利水电出版社,2006:1-4
[49]陈伯蠡.焊接工程缺欠分析与对策[M].机械工业出版社,1997.
[50]张浩,王国安,邓海编著.压力钢管有限元分析[J].四川水利发 电,2004,23:103-105.
[51]赵建平.随机有限元方法及其在压力容器缺陷安全评定中的应用:[学位论文].南京:南京化工大学,1997.
[52]王光钦,雷斌隆.引水压力钢管表面凹坑缺陷应力扩大系数及其估算方法[J].西南交通大学学报,1997,32(2):130-135.
[53]王光钦,雷斌隆.含凹坑缺陷压力钢管的安全评定[J].水力发电,1997(10):55-58.
[2]俞树容,王志文.压力容器安全评定的现代方法[J].化工机械1995,22(3):52-55
[3]Wilkowski G M,Others,Short Cracks in Piping and Piping Welds.Seminnual Reports by Battelle,NUREG/CR-4599,1991,1(1,2);1992,2(1,2);1993,3(1);1994,4(2),U.S.Nuclear Regulatory Commission Washington.D.C.
[4]ASME Nuclear Power Plants Components Code Nc-3658,ASME Section Ⅲ.
[5][美]库默等著,周洪范等译.弹塑性断裂分析工程方法(ERPI报告NP-1931)[M].国防工业出版社,1985.
[6]Wilkowski G M,Others.Degraded Piping Program Phase I Summary of Technical Results and Their Sinificance to Leak-Before-Break and in Service Flaw Acceptance Criteria,March 1984-Jannuary 1989.NUREG/CR-4082,Vol,8tU.S.Nuclear Regulatory Commision,Washington,D.C.March,1989.
[7]R.W.尼柯尔斯[英]主编,李建国等译.压力容器技术进展—5规范和标准.机械工业出版社,1992.
[8]Schulz.The Evalution of the Break Preclusion Concept for Nuclear Power Piant in Germany.Paper,4,Specialist Meeting on Leak Before Break in Reactor Piping and Vessels.Lyon,France,Oct,1995.
[9]李培宁等.国际压力容器缺陷工程评定技术进展[J].压力器,1991,8(2):3-6.
[10]沈士明.在役压力管道安全评定研究的现状与发展[J]中国机械工 程,1997,8(3):101-104.
[11]Hoppar AtMayfieldM,Olson R,et al,Overview of the IPING·I Program Seismic Loaded Creaked Piping System Experiments,SMIRT-13Conference,Parto Ahgre,Brazil,August,1995.
[12]钟群鹏等.中国压力容器安全评定技术的研究应用和发展[J].中国锅炉压力容器安全,1997,13(2):4-9.
[13]钟群鹏等.我国压力容器安全评定技术的现状和发展[J]中国机械工程,1997,8(5):95-100.
[14]压力容器缺陷评定规范编制组.压力容器缺陷评定规范CVDA-1984.
[15]中华人民共和国国家质量监督检验疫总局,中国国家标准化管理委员会.GB/T19624-2004在用含缺陷压力容器安全评定[S].北京:中国标准化出版社,2004.
[16]王文和,沈士明等.含缺陷压力管道安全评定方法研究的现状与发展.管道技术与设备,2007,(2).
[17]Rahman S,Brust F,Ghadiali N et al.Recent Evaluations of crack-Opening-Area in Circumferentiatly Cracked Pipes,Paper 24,3.Specialist Meeting on Leak Before Break in Reactor Piping and Vessels,Lyon,France,Oct,1995.
[18]Ktecker,R.,Brnst,F.,and Wilkowsk,G.M.NRC Leak Before Break (LBB·NRC)Analysis Method for Circumferentlally Through-Wall Cracked Pipes under Axial Plus Bending Loads.NUREG/CR-4572 May 1986.
[19]Metals Handbook,9~(th)ed.vol.11,Failure Analysis and Prevention,ASM,Ohio,1980.
[20]彭在美.国内钢管业的发展方向.管道技术与设备,2005(4):22-23.
[21]田锡唐.焊接结构[M].北京:机械工业出版社,1993.10.
[22]天津大学焊接教研室.金属熔焊原理及工艺[M].北京:机械工业出版社,1981.
[23]周振丰,张文钱.焊接冶金与金属焊接性[M].第2版.北京:机械工业出版社,1988.11
[24]姜换中.电弧焊与电渣焊[M].北京:机械工业出版社,1988.11.
[25]高勇,雷斌隆,高先安.断裂力学和有限元法在工程机械安全评定中的应用.矿山机械,2004(5).
[26]沈成康.断裂力学[M].同济大学出版社,1996:1-7
[27]戴振羽.断裂力学基础教程[M].西南交通大学出版社,2007:2-5.
[28]吴家龙.弹性力学[M].高等教育出版社,2001.
[29]丁桂宝等著.弹塑性力学[M].西南交通大学出版社,2006.
[30]霍立兴.焊接结构的断裂行为及评定[M].机械工业出版社,2000:149-241.
[31]沈士明,赵建平著.压力管道安全评定技术的进展.压力容器[J],2007:58-66.
[32]王志文,李培宁,琚定一等.压力容器断裂评定理论及规范的新发展.石油化工设备,1988,17(3):1-4.
[33]徐宏.压力管道缺陷评定工程方法.华东理工大学博士学位论文.1995.
[34]周剑秋,沈士明.失效评定图在含缺陷压力管道断裂评定中应用.化工机械,1997,24(2):16-29.
[35]王宗杰.焊接工程综合试验技术[M].机械工业出版社,1997.6.
[36]华东化工学院化机所译.有缺陷结构完整性的评定标准R/H/R6[S].第三版.化学工业部设备设计中心站,1998.
[37]李培宁.国外压容器和工业结构缺陷评定规范的新进展[R].华东理工大 学.
[38][美]库默等著,董亚民等译.弹塑性断裂分析进展(ERPI报告NP-3607)[M].清华大学工程力学研究所,1984.
[39]ERPI and Novelech Comporation.Ductile Fracture Handbook.Volumel(R),Research Reports Center Palo Alto.California.1991.
[40]SINrAP.Structure Integrity Assessment Procedure for Europe Industry Project BE 95-1426.Final Procedure[S],British Steel Report,Rotherham 1999.
[41]ASME B&PV Code N-480[S].Examination Requirements for Pipe Well Thinning Due to Single Phase Erosion and Corrosion,Section Ⅺ,Division 1,1990.
[42]李培宁.各国缺陷评定规范的发展.国家质量技术监督局锅炉压力容器检测中心网.
[43]王勖成.有限单元法[M].清华大学出版社,2005:5-8.
[44]朱伯芳.有限单元法原理和应用[M],第2版.中国水利电力出版社.1998.
[45]康国政编著.大型有限元程序的原理、结构与使用[M].西南交通大学出版社,2004.
[46]杜平安,甘娥忠,于亚婷编著.有限元法—原理、建模及应用[M].国防工业出版社,2004.
[47]余伟炜,高炳军等著.ANSYS在机械与化工装备中的应用[M]中国水利水电出版社.2006:1-3.
[48]博弈工作室.ANSYS9.0经典产品基础教程与实例详解[M].中国水利水电出版社,2006:1-4
[49]陈伯蠡.焊接工程缺欠分析与对策[M].机械工业出版社,1997.
[50]张浩,王国安,邓海编著.压力钢管有限元分析[J].四川水利发 电,2004,23:103-105.
[51]赵建平.随机有限元方法及其在压力容器缺陷安全评定中的应用:[学位论文].南京:南京化工大学,1997.
[52]王光钦,雷斌隆.引水压力钢管表面凹坑缺陷应力扩大系数及其估算方法[J].西南交通大学学报,1997,32(2):130-135.
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