文档介绍：西南交通大学硕士研究生学位论文第1页摘要整体节点是近年来在大跨度钢桁桥中采用的一种新型结构型式。整体节点属于厚板焊接,不仅焊缝密集,而且焊缝类型多样。在车辆移动荷载作用下,这种复杂焊接结构的疲劳可靠性有待于进一步研究。本文结合重庆菜园坝公轨两用长江大桥轨道横梁与整体节点连接可靠性疲劳试验,重点研究了疲劳试验荷载的取值,同时分析了该桥整体节点构造细节的疲劳性能。首先,本文介绍了钢桥疲劳的一些基本概念;分析了影响钢桥疲劳的主要因素;比较各种疲劳损伤累积理论计算方法的优缺点。其次,简要介绍了目前国内外对钢桥疲劳荷载谱的研究状况,分别讨论了公路和铁路钢桥疲劳荷载谱的制定方法,具体给出了英国、美国等国家桥梁设计规范中对钢桥疲劳荷载谱的两种计算方法,迸一步对比分析这两个规范公路疲劳荷载谱计算方法的优缺点。最后,以重庆菜园坝长江大桥为背景,重点研究了公轨两用钢桁桥疲劳荷载谱的制定方法,提出了重庆跨座式轨道交通荷载作用下的桥梁荷载谱。在此基础上,给出该桥轨道横梁与整体节点连接可靠性疲劳试验的试验荷载, 设计了本次疲劳试验的试验模型。通过对疲劳试验模型的有限元分析,计算出试验模型的应力分布,并制定出疲劳试验方案。关键词钢桥疲劳;整体节点;疲劳试验:荷载谱;疲劳损伤累积理论西南交通大学硕士研究生学位论文第||页 Abstract Integraljoint is anew—type structure thathas been already adopted inthelong span steel truss bridge inthelastfew are assembled withthick steelplate only arewelding seams dense,but also thetypes of welding seams are various are alotoffactors which affect jtmctural fatigue fatigueresistance plicated welded s仃uctLlre subjected tomoving vehicle loadsneeds thefatigue testforconnecting reliability oftrack cross beam and integraljoint ofChongqing Caiyuanba Yangtze double—deck Bridge as aninstantce,the testload andthefatigue reliability of theintegraljoint details are studiedinthis contents are inthefollowings. onceptions ofsteelbridge fatigue are main factors causing steel bridge fatigue are advantages and disadvantages ofthefatiguedamage cumulative rules arediscussed. Secondly,fatigue loadspectrums ofhighway and railway arestudied,and the presently domestic and international research statetofatigue loadspectrum ofsteel bridge isbriefly thesisintroduces thefatigue load spectrum of BritishStandards/nstitution BS5400 and AASHTO bridge design andanalyzes thefatiguedesign methods ofthetwodesign standards. Atlast,the thesisemphatically studiesthefatigue loadspectrum ofdouble-deck bridge,and provides thefatigue load spectrum ofbridges th