新型正交异性钢桥面板抗疲劳优化设计

发布时间：2018-03-07 03:07

本文选题：正交异性钢桥面板　切入点：新型纵肋　出处：《西南交通大学》2015年硕士论文　论文类型：学位论文

【摘要】：正交异性钢桥面板因具有承载能力大、重量轻、制造加工方便等优点,并广泛应用于大跨度钢桥中。但在使用过程中,结构出现了大量的疲劳裂纹,严重影响桥梁的使用性能。为改善正交异性板钢桥面的疲劳性能,做的主要工作和相应结论如下：(1)通过调研既有正交异性板钢桥的疲劳病害发现,出现疲劳裂纹较多的部位有4个。总结了国内外相关研究成果,为改善结构的疲劳性能,国外有学者提出新型正交异性板结构。(2)分析各疲劳易损部位的损伤机理。针对正交异性板的受力特点,指出疲劳裂纹是荷载和面外变形共同作用的结果,设计参数和构造细节对关键部位的疲劳性能有重要影响。(3)分别建立传统和两种新型正交异性板的有限元模型,沿横向和纵向变换加载位置,对比各疲劳易损部位的名义应力幅和面外变形情况。分析结果表明：新型正交异性板结构在纵肋一顶板焊缝处出现了更大的竖向挠曲变形,进而产生了更大的应力幅,疲劳性能较差,需要进一步优化；对于纵肋—横隔板焊缝和横隔板开槽部位,相应部位的面外变形与应力幅没有明显关系,但400mm纵肋的结构产生的应力幅最小,疲劳性能较优。(4)以应力幅和面外变形为指标,针对纵肋跨度为400mm的新型正交异性板结构,进行设计参数优化和构造细节优化,同时讨论了应力与面外变形的关系。分析结果表明：顶板的竖向挠曲变形和D1、D2、D3点的应力幅随顶板厚度的增加而减小,横隔板厚度对面外变形和应力幅的影响不大,增加纵肋的厚度是有利的,横隔板间距从4m增加到8m,跨中挠度增加了2倍；加入顶部小隔板后明显减小了顶板的竖向挠度,也使应力幅减小了72.4%。最后给出一种疲劳性能较优的正交异性板结构方案。
[Abstract]:Orthotropic steel bridge face plate is widely used in long span steel bridge due to its advantages of large bearing capacity, light weight, convenient manufacturing and processing. However, a large number of fatigue cracks appear in the structure during the process of use. In order to improve the fatigue performance of orthotropic steel deck, the main work and corresponding conclusions are as follows: 1. In order to improve the fatigue performance of the structure, there are 4 parts where there are more fatigue cracks. The related research results at home and abroad are summarized in order to improve the fatigue performance of the structure. According to the stress characteristics of orthotropic plate, it is pointed out that the fatigue crack is the result of the joint action of load and out-of-plane deformation. The design parameters and construction details have important influence on the fatigue performance of key parts.) respectively, the finite element models of traditional and two new orthotropic plates are established, and the loading positions are transformed along the transverse and longitudinal directions. By comparing the nominal stress amplitude and the out-of-plane deformation of the fatigue vulnerable parts, the results show that the new orthotropic plate structure has a larger vertical flexural deformation at the weld seam of longitudinal rib-roof plate, and then produces a larger stress amplitude. The fatigue performance is poor and needs to be further optimized. For the weld seam of longitudinal rib-transverse partition and slotted transverse diaphragm, the out-of-plane deformation of the corresponding part has no obvious relationship with the stress amplitude, but the stress amplitude of the 400mm longitudinal rib is the smallest. For a new orthotropic plate structure with a longitudinal rib span of 400mm, the design parameters and construction details are optimized, taking the stress amplitude and out-of-plane deformation as the indexes. At the same time, the relationship between stress and out-of-plane deformation is discussed. The results show that the vertical flexural deformation of the roof and the stress amplitude at D1D2D3 decrease with the increase of the thickness of the roof, but the influence of the thickness of the transverse partition on the outside deformation and stress amplitude is not significant. It is advantageous to increase the thickness of longitudinal rib, the distance of transverse diaphragm is increased from 4m to 8m, the deflection of span increases by 2 times, and the vertical deflection of roof is obviously reduced with the addition of small partition at the top. The stress amplitude is also reduced by 72.4. Finally, an orthotropic plate structure with better fatigue performance is proposed.
【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】：U443.31

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