基于缺口应力法的焊接接头疲劳分析
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摘要
等效缺口应力法作为焊接疲劳分析的一种局部方法,不仅克服了焊接结构名义应力难以确定和焊根结构应力无法定义的困难,而且能够反映焊接局部后处理对焊接接头疲劳强度的影响,因此近年来备受关注。该文建立了典型焊接接头的三维缺口应力模型,对焊趾根部的缺口应力集中系数进行了求解;通过对对接接头和纵向角接头在焊后未处理(AS-weld)和超声喷丸处理(UPT)两种状态下的疲劳试验数据进行分析处理,获得了两种焊接接头在缺口应力系统下统一的S-N曲线,并与目前国际焊接学会所推荐的具有相同存活率的疲劳寿命曲线(IIW:m=3,FAT=225)进行比较,结果表明,该曲线具有更高的疲劳等级和更低的斜度。
The notch stress method(NSM) is a local method of welding fatigue analysis, which has attracted much attention in recent years. Traditionally, the nominal stresses in welded structures are difficult to determine and the weld root stress cannot be defined, but NSM can not only successfully overcome these problems but also assess the effects of welded joint fatigue strength with local welding post-processing. In this paper, 3D notch stress models of typical welded joints are presented to solve the notch stress concentration factors(n SCF) in a weld toe. Some fatigue test data from butt joints and longitudinal fillet joints are referenced from literature, which include two conditions: As-weld and ultrasonic peening treatment(UPT); then unified S-N curves under notch stress system are obtained by combining the n SCF and fatigue data. Compared to the referenced fatigue-life curve of International Institute of Welding(IIW: m=3, FAT=225) at the same survival probability, it shows that these fitting curves have higher fatigue classes and shallower slopes.
The notch stress method(NSM) is a local method of welding fatigue analysis, which has attracted much attention in recent years. Traditionally, the nominal stresses in welded structures are difficult to determine and the weld root stress cannot be defined, but NSM can not only successfully overcome these problems but also assess the effects of welded joint fatigue strength with local welding post-processing. In this paper, 3D notch stress models of typical welded joints are presented to solve the notch stress concentration factors(n SCF) in a weld toe. Some fatigue test data from butt joints and longitudinal fillet joints are referenced from literature, which include two conditions: As-weld and ultrasonic peening treatment(UPT); then unified S-N curves under notch stress system are obtained by combining the n SCF and fatigue data. Compared to the referenced fatigue-life curve of International Institute of Welding(IIW: m=3, FAT=225) at the same survival probability, it shows that these fitting curves have higher fatigue classes and shallower slopes.
引文
[1]张彦华.焊接结构疲劳强度分析[M].北京:化学工业出版社,2013:118―122.Zhang Yanhua.Fatigue strength analysis of welded structure[M].Beijing:Chemical Industry Press,2013:118―122.(in Chinese)
[2]Radaj D,Sonsino C M,Fricke W.Fatigue Assessment of welded joints by local approaches[M].Cambridge:Woodhead Publishing and Maney Publishing,2006:92―99.
[3]Sonsino C M.Notch stress concepts for the fatigue assessment of welded joints-Background and applications[J].International Journal of Fatigue,2012,34(1):2―16.
[4]邱宝象,高增梁,王效贵,冯淼林.基于有限元法的16Mn R缺口件疲劳寿命预测方法[J].工程力学,2010,27(8):21―27.Qiu Baoxiang,Gao Zengliang,Wang Xiaogui,Feng Miaolin.A fatigue life prediction method for 16mnr steel notched components based on the finite element method[J].Engineering Mechanics,2010,27(8):21―27.(in Chinese)
[5]吴志荣,胡绪腾,宋迎东.多轴载荷下缺口件的疲劳寿命估算方法[J].工程力学,2014,31(10):216―221.Wu Zhirong,Hu Xuteng,Song Yingdong.Estimation method for fatigue life of notched specimen under multiaxial loading[J].Engineering Mechanics,2014,31(10):216―221.(in Chinese)
[6]Radaj D,Vormwald M.Advanced methods of fatigue assessment[M].Berlin:Springer,2013:12―15.
[7]Radaj D,Lazzarin P,Berto F.Generalized Neuber concept of fictitious notch rounding[J].International Journal of Fatigue,2013,51(6):105―115.
[8]IIW-Doc XIII-2240rl-08/XV-1289rl-08,Guideline for the fatigue assessment by notch stress analysis for welded structures[S].Cambridge:Woodhead Publishing,2012.
[9]IIW doc.XIII2151r1/XV-1254r1-07,Fatigue design of welded joints and components[S].Cambridge:Abington Publishing,2007.
[10]Pedersen M M.Re-analysis of fatigue data for welded joints using the notch stress approach[J].International Journal of Fatigue,2010,32(10):1620―1626.
[11]Wang Ting,Wang Dongpo,Huo Lixing.Discussion on fatigue design of welded joints enhanced by ultrasonic peening treatment(UPT)[J].International Journal of Fatigue,2009,31(4):644―650.
[12]拉达伊.焊接结构疲劳强度[M].郑朝云,张式成,译.北京:机械工业出版社,1994:9―20.Radaj D.Fatigue strength of welded structure[M].Translated by Zheng Chaoyun,Zhang Shicheng.Beijing:China Machine Press,1994:9―20.(in Chinese)
[13]王东坡,田瑞莹,霍立兴.超声冲击处理焊接接头疲劳设计若干问题的探讨[J].机械工程学报,2006,11(42):173―178.Wang Dongpo,Tian Ruiying,Huo Lixing.Discussion about improving fatigue performance of welded joint by ultrasonic peening[J].Journal of Mechanical Engineering,2006,11(42):173―178.(in Chinese)
[14]Halid Can Yildirim,Gary B.Marquis.Fatigue strength improvement factors for high strength steel welded joints treated by high frequency mechanical impact[J].International Journal of Fatigue,2012,44(11):168―176.
[15]Sonsino C M.A consideration of allowable equivalent stresses for fatigue design of welded joints according to the notch stress concept with the reference radii ref=1.00and 0.05 mm[J].Welding in the World,2009,53(3/4):R64―R74.
[2]Radaj D,Sonsino C M,Fricke W.Fatigue Assessment of welded joints by local approaches[M].Cambridge:Woodhead Publishing and Maney Publishing,2006:92―99.
[3]Sonsino C M.Notch stress concepts for the fatigue assessment of welded joints-Background and applications[J].International Journal of Fatigue,2012,34(1):2―16.
[4]邱宝象,高增梁,王效贵,冯淼林.基于有限元法的16Mn R缺口件疲劳寿命预测方法[J].工程力学,2010,27(8):21―27.Qiu Baoxiang,Gao Zengliang,Wang Xiaogui,Feng Miaolin.A fatigue life prediction method for 16mnr steel notched components based on the finite element method[J].Engineering Mechanics,2010,27(8):21―27.(in Chinese)
[5]吴志荣,胡绪腾,宋迎东.多轴载荷下缺口件的疲劳寿命估算方法[J].工程力学,2014,31(10):216―221.Wu Zhirong,Hu Xuteng,Song Yingdong.Estimation method for fatigue life of notched specimen under multiaxial loading[J].Engineering Mechanics,2014,31(10):216―221.(in Chinese)
[6]Radaj D,Vormwald M.Advanced methods of fatigue assessment[M].Berlin:Springer,2013:12―15.
[7]Radaj D,Lazzarin P,Berto F.Generalized Neuber concept of fictitious notch rounding[J].International Journal of Fatigue,2013,51(6):105―115.
[8]IIW-Doc XIII-2240rl-08/XV-1289rl-08,Guideline for the fatigue assessment by notch stress analysis for welded structures[S].Cambridge:Woodhead Publishing,2012.
[9]IIW doc.XIII2151r1/XV-1254r1-07,Fatigue design of welded joints and components[S].Cambridge:Abington Publishing,2007.
[10]Pedersen M M.Re-analysis of fatigue data for welded joints using the notch stress approach[J].International Journal of Fatigue,2010,32(10):1620―1626.
[11]Wang Ting,Wang Dongpo,Huo Lixing.Discussion on fatigue design of welded joints enhanced by ultrasonic peening treatment(UPT)[J].International Journal of Fatigue,2009,31(4):644―650.
[12]拉达伊.焊接结构疲劳强度[M].郑朝云,张式成,译.北京:机械工业出版社,1994:9―20.Radaj D.Fatigue strength of welded structure[M].Translated by Zheng Chaoyun,Zhang Shicheng.Beijing:China Machine Press,1994:9―20.(in Chinese)
[13]王东坡,田瑞莹,霍立兴.超声冲击处理焊接接头疲劳设计若干问题的探讨[J].机械工程学报,2006,11(42):173―178.Wang Dongpo,Tian Ruiying,Huo Lixing.Discussion about improving fatigue performance of welded joint by ultrasonic peening[J].Journal of Mechanical Engineering,2006,11(42):173―178.(in Chinese)
[14]Halid Can Yildirim,Gary B.Marquis.Fatigue strength improvement factors for high strength steel welded joints treated by high frequency mechanical impact[J].International Journal of Fatigue,2012,44(11):168―176.
[15]Sonsino C M.A consideration of allowable equivalent stresses for fatigue design of welded joints according to the notch stress concept with the reference radii ref=1.00and 0.05 mm[J].Welding in the World,2009,53(3/4):R64―R74.