横向多迹线加载对正交异性钢桥面板疲劳行为的影响

发布时间：2019-03-04 18:03

【摘要】：正交异性钢桥面板的疲劳问题较为突出,疲劳破坏已成为钢桥面板结构的主要破坏形式之一,因此进行合理的抗疲劳设计尤为重要,而抗疲劳设计的核心问题之一是准确计算疲劳应力谱。目前计算易损细节的疲劳应力谱时一般采用车道面内单迹线加载的方式,不考虑轮迹横向分布概率的影响,致使计算应力谱与真实应力谱之间存在一定差异。论文以港珠澳大桥正交异性钢桥面板中三种典型疲劳易损细节为研究对象,系统研究了国内外三种典型的轮迹横向分布概率模型对易损细节疲劳应力幅的影响。主要工作如下：(1)简要介绍了正交异性钢桥面板在国内外的发展应用,对正交异性钢桥面板疲劳问题及其产生原因、研究现状进行了简要阐述。介绍了正交异性钢桥面板疲劳研究的基础理论,包括钢桥疲劳的定义,与疲劳研究相关的几个重要基本概念,着重介绍了三种疲劳累积损伤理论及其推导过程,变幅疲劳与常幅疲劳的等效换算以及抗疲劳设计方法的几种基本设计理念。(2)系统梳理并对比分析了国内外轮迹横向分布研究,分析发现国内外车辆轮迹存在一定差异,我国车辆中心线横向分布的分散程度相对较大。(3)以港珠澳大桥前期系统研究为背景,确定了易损细节研究对象,根据对比分析选取了三种典型轮迹横向分布概率模型,参考三种计算方法所得结果最终确定了标准疲劳车,采用通用有限元软件ANSYS建立了实桥疲劳控制梁段的三维板壳元分析模型,通过系统横向加载确定了易损细节所处位置。(4)按照车道面内横向多迹线加载的方法计算了各轮迹的应力历程,对其进行了系统的对比分析；分析计算了横向各轮迹的车辆加载对等效应力幅的贡献,对其贡献大小进行了对比分析；分析计算了各横向分布概率模型对应的单迹线加载应力幅折减系数,并对折减系数的波动程度和变化规律进行了对比分析。(5)给出了论文的主要研究结论,并对轮迹横向分布影响的后续研究进行了展望。
[Abstract]:The fatigue problem of orthotropic steel bridge deck is more prominent, fatigue failure has become one of the main failure forms of steel bridge slab structure, so it is very important to carry out reasonable anti-fatigue design. One of the key problems in anti-fatigue design is the accurate calculation of fatigue stress spectrum. At present, the fatigue stress spectrum of vulnerable details is usually calculated by single trace loading mode in the lane plane, without considering the influence of the lateral distribution probability of the track, so there is a certain difference between the calculated stress spectrum and the real stress spectrum. Taking three typical fatigue vulnerable details in orthotropic steel deck of Hong Kong-Zhuhai-Macao Bridge as the research object, the effects of three typical lateral distribution probability models of wheel tracks at home and abroad on fatigue stress amplitude of vulnerable details are systematically studied in this paper. The main work is as follows: (1) the development and application of orthotropic steel bridge deck at home and abroad are briefly introduced. The fatigue problem of orthotropic steel bridge deck and its causes are briefly described. This paper introduces the basic theory of fatigue research of orthotropic steel bridge deck, including the definition of fatigue of steel bridge, several important basic concepts related to fatigue research, and emphatically introduces three kinds of fatigue cumulative damage theory and its derivation process. The equivalent conversion between variable amplitude fatigue and constant amplitude fatigue as well as several basic design concepts of anti-fatigue design methods are presented. (2) the lateral distribution of wheel tracks at home and abroad is systematically combed and analyzed, and it is found that there are some differences in vehicle tracks at home and abroad. The dispersion degree of transverse distribution of vehicle centerline is relatively large in China. (3) based on the previous system research of Hong Kong-Zhuhai-Macao Bridge, the research object of vulnerable detail is determined, and three kinds of typical lateral distribution probability models of wheel tracks are selected according to the comparative analysis. The standard fatigue vehicle is finally determined according to the results of three calculation methods. The three-dimensional plate-shell element analysis model of the fatigue control beam segment of the real bridge is established by using the general finite element software ANSYS. The location of vulnerable details is determined by lateral loading of the system. (4) the stress history of each wheel track is calculated according to the method of lateral multi-trace loading in the lane plane, and the comparative analysis is carried out. The contribution of the load equivalent force amplitude of each wheel track is analyzed and analyzed, and the contribution size of the vehicle load equivalent force amplitude is compared and analyzed. The single trace loading stress amplitude reduction coefficient corresponding to each lateral distribution probability model is analyzed and calculated, and the fluctuation degree and variation rule of the reduction coefficient are compared and analyzed. (5) the main research conclusions of the paper are given. The future research on the influence of the lateral distribution of the wheel track is prospected.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U441.4;U443.31

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