U肋构造及横隔板开孔形式对正交异性钢桥面板疲劳性能的影响

发布时间：2018-04-02 18:49

本文选题：正交异性钢桥面板疲劳　切入点：构造细节　出处：《西南交通大学》2015年硕士论文

【摘要】：正交异性钢桥面板由于其自重较传统的混凝土面板轻,可有效控制其预制及施工质量,现场拼装方便快速,受力性能较优、行车舒适性好而变得越来越广泛应用于长大跨度桥梁,如悬索桥和斜拉桥等。但是,由于正交异性钢桥面板系统有着纵、横、竖三向通过栓焊连接在一起的复杂板件结构,并相应地导致连接部位结构性应力状况复杂,且由于焊接过程中常常存在残余应力集中,导致部分构造细节处易发生疲劳开裂,直接影响桥梁的安全和性能。文章以其中一个构造细节—纵肋和横隔板连接处,亦即最易发生疲劳损伤破坏的一个细节处为研究对象,对正交异性钢桥面板疲劳开裂的问题进行研究和优化。文章主要工作如下：(1)对正交异性钢桥面板的起源,研究现状,计算理论,焊接工艺等进行了归纳总结。(2)阐述国内外针对U肋和横隔板连接处疲劳试验研究的成果,针对此连接处开裂主要出现的部位,即U肋和横隔板竖向连接焊缝处竖向裂纹、横隔板弧形开口端部横向裂缝、焊趾下部纵肋横向裂缝,分析其各自的成因。(3)为提高正交异性钢桥面板U肋和横隔板连接处的抗疲劳性能,分析此处横隔板和U肋各自的应力组成情况,通过选取AASHTO规范推荐的纵肋和横隔板形式,建立了精细的实体元数值分析模型,加载后得出面内应力和面外应力所占比大小,为此处细节的局部加强和抗疲劳性能优化提供依据。(4)在得出纵肋和横隔板各自面内应力和面外应力所占比例的基础上,从设计构造上对此细节进行优化,研究讨论了此处局部刚度加强的一些措施,包括在纵肋内部焊接纵肋梯形小隔板、内部加劲肋等,在此基础上,分别研究分析了正交异性钢桥未焊接和焊接纵肋小隔板之后,改变顶板厚度、横隔板厚度、U肋厚度等对此细节处受力性能的影响。
[Abstract]:Because the orthotropic steel bridge face plate is lighter than the traditional concrete face slab, it can effectively control its prefabrication and construction quality, and it is convenient and quick to assemble on site, and its mechanical performance is better.Driving comfort has become more and more widely used in long span bridges, such as suspension bridges and cable-stayed bridges.However, the orthotropic steel bridge panel system has a complex plate structure connected by bolting and welding in longitudinal, transverse and vertical directions, which leads to the complex structural stress condition in the connection position.Due to the residual stress concentration in welding process, some structural details are prone to fatigue cracking, which directly affects the safety and performance of the bridge.In this paper, the problem of fatigue cracking of orthotropic steel bridge face slab is studied and optimized by taking one of the structural details, the joint of longitudinal rib and transverse partition, that is, one of the most vulnerable to fatigue damage and failure, as the research object.The main work of this paper is as follows: (1) summarizing the origin, research status, calculation theory and welding process of orthotropic steel bridge panel. (2) expounding the results of fatigue test at the joint of U rib and transverse diaphragm at home and abroad.In view of the main cracks in the joint, that is, the vertical crack in the weld seam between U rib and transverse partition plate, the transverse crack in the arc end of transverse partition plate, the transverse crack in longitudinal rib at the bottom of the weld toe, and the transverse crack in the longitudinal rib at the bottom of the weld toe.In order to improve the fatigue resistance of the joint between U rib and transverse diaphragm of orthotropic steel bridge, the stress composition of transverse diaphragm and U rib is analyzed. The longitudinal rib and transverse partition form recommended by AASHTO code are selected.A fine numerical analysis model of solid element is established. After loading, the ratio of internal stress and out-of-plane stress is obtained.To provide the basis for the local strengthening and fatigue performance optimization of the detail here. (4) on the basis of finding out the proportion of the in-plane stress and the out-of-plane stress of the longitudinal rib and the transverse diaphragm, the detail is optimized from the design and construction.In this paper, some measures to strengthen the local stiffness are studied and discussed, including welding trapezoidal diaphragm and stiffening rib inside longitudinal rib. On the basis of this, the paper studies and analyzes the joint of longitudinal rib small partition without welding or welding longitudinal rib in orthotropic steel bridge.The influence of the thickness of roof and the thickness of U rib on the mechanical performance of this detail.
【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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