钢-UHPC轻型组合桥面板中短栓钉的静力及疲劳性能研究

发布时间：2018-01-15 21:02

本文关键词：钢-UHPC轻型组合桥面板中短栓钉的静力及疲劳性能研究　出处：《西南交通大学》2017年硕士论文　论文类型：学位论文

【摘要】：钢-UHPC轻型组合桥板通过栓钉将钢结构和UHPC层组合成一个整体,在提高钢桥面板刚度的同时自重也得到了很好地控制,可以有效的解决钢结构和铺装层疲劳病害的问题。UHPC层的厚度一般在50mm左右,为了满足保护层厚度的要求,栓钉的高度受到了严格的限制,其长径比通常小于4,属于典型的短栓钉。同时,由于UHPC的力学性能与普通混凝土存在显著差异,其破坏模式、承载力及疲劳特性均区别于普通混凝土组合结构中的传统栓钉,但当前相关研究仍较为欠缺。为研究短栓钉在轻型组合桥面板中的静力和疲劳性能,进行了以下研究工作:(1)回顾总结了正交异性刚桥面板的疲劳病害和成因以及传统铺装层的病害和原因,介绍了 UHPC的力学参数、钢-UHPC轻型组合桥面板的概念与研究现状以及其中适用的剪力连接件。(2)借助ABAQUS软件,对短栓钉进行了非线性有限元分析。通过对短栓钉的变形和应力分布的分析表明栓钉并非是纯剪状态,而是处于受弯、受剪、受拉的复杂应力状态。另外,通过与普通栓钉作对比得出结论:短栓钉的变形与应力分布和普通栓钉基本一致,但是抗剪效率更高,承载力满足要求。(3)通过对短栓钉承载力影响因素的分析,研究表明栓钉的直径、混凝土强度是影响其承载力和抗剪刚度的关键因素,而栓钉的高度对其承载力和抗剪刚度影响较小。同时,钢UHPC之间的界面摩擦对承载力有一定影响,但是对抗剪刚度影响显著,界面摩擦可以使得抗剪刚度提高16%左右。(4)对于短栓钉的疲劳试验数据进行了统计分析,并与规范以及其他经典疲劳计算公式进行了对比研究。研究结果表明:现有的疲劳公式对短栓钉不再适用,基于此,文章提出了基于主应力而非剪应力的指标来评价短栓钉的疲劳性能,并确定了其疲劳抗力为FAT90。(5)建立梁式有限元模型并确定短栓钉结构的疲劳易损位置和细节,通过名义应力法评价其疲劳性能。研究表明短栓钉的疲劳寿命满足设计要求。
[Abstract]:Steel-UHPC light composite bridge plate combines steel structure and UHPC layer into a whole through studs, which can improve the stiffness of steel bridge panel and control the weight of the steel bridge panel at the same time. The thickness of UHPC layer is generally about 50mm, in order to meet the requirements of the thickness of the protective layer, the height of the bolt is strictly restricted. The ratio of length to diameter is usually less than 4, which is a typical short bolt. At the same time, the failure mode of UHPC is due to the obvious difference between the mechanical properties of UHPC and ordinary concrete. The bearing capacity and fatigue characteristics are different from the traditional bolt in the ordinary concrete composite structure, but the related research is still relatively lacking. In order to study the static and fatigue performance of the short bolt in the light composite deck slab. The following research work is done: 1) the fatigue diseases and causes of orthotropic rigid bridge deck and the diseases and causes of traditional pavement are summarized, and the mechanical parameters of UHPC are introduced. The concept and research status of steel-UHPC light composite deck slab and the suitable shear connector. 2) with the help of ABAQUS software. Through the analysis of deformation and stress distribution of the bolt, it is shown that the bolt is not a pure shear state, but is in the complex stress state of bending, shear and tension. By comparing with the common bolt, it is concluded that the deformation and stress distribution of the bolt are basically the same as that of the common bolt, but the shear efficiency is higher. Through the analysis of the factors affecting the bearing capacity of the studs, the research shows that the diameter of the studs and the strength of concrete are the key factors affecting the bearing capacity and shear stiffness of the studs. However, the height of bolt has little effect on the bearing capacity and shear stiffness. At the same time, the interface friction between steel UHPC has a certain effect on the bearing capacity, but the impact of anti-shear stiffness is significant. The interface friction can increase the shear stiffness by about 16%.) the fatigue test data of the studs are statistically analyzed. The results show that the existing fatigue formula is no longer applicable to the stud, and based on this, the fatigue calculation formula is compared with the code and other classical fatigue calculation formulas, and the results show that the existing fatigue formula is no longer applicable to the stud. In this paper, the index of principal stress rather than shear stress is proposed to evaluate the fatigue performance of the stud. The fatigue resistance of FAT90. 5) the beam finite element model is established and the fatigue vulnerability position and details of the short bolt structure are determined. The fatigue performance was evaluated by the nominal stress method. The results show that the fatigue life of the stud meets the design requirements.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U441;U443.31

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