【作者】 任伟平；

【导师】 强士中；

【作者基本信息】 西南交通大学 ， 桥梁与隧道工程， 2004， 硕士

【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，进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。更多还原

【Abstract】 Integral joint is a new-type structure that has been already adopted in the long span steel truss bridge in the last few years. Integral joints are assembled with thick steel plate by welding. Not only are welding seams dense, but also the types of welding seams are various in the integral joint. There are a lot of factors which affect structural fatigue strength. The fatigue resistance of complicated welded structure subjected to moving vehicle loads needs to be further researched . Taking the fatigue test for connecting reliability of track cross beam and integral joint of Chongqing Caiyuanba Yangtze double-deck Bridge as an instantce, the test load and the fatigue reliability of the integral joint details are studied in this thesis. The main contents are in the followings.First of all, some basic conceptions of steel bridge fatigue are introduced.The main factors causing steel bridge fatigue are analyzed.The advantages and disadvantages of the fatigue damage cumulative rules are discussed.Secondly, fatigue load spectrums of highway and railway are studied, and the presently domestic and international research state to fatigue load spectrum of steel bridge is briefly introduced. The thesis introduces the fatigue load spectrum of British Standards Institution BS5400 and AASHTO bridge design standards, then compares and analyzes the fatigue design methods of the two design standards.At last, the thesis emphatically studies the fatigue load spectrum of double-deck bridge, and provides the fatigue load spectrum of bridges that bear straddle type monorail loads. Based on this, the thesis concludes the fatigue test load of Chongqing Caiyuanba Bridge, and fatigue test model is designed.By using a three dimensional FEM model of the fatigue test model, the factors of stress concentrateion of critical regions are obtained, and the test method is provided.更多还原