钢筋混凝土简支梁桥的振动效应与疲劳特性的研究

发布时间：2018-04-19 15:03

本文选题：疲劳性能 + 结构振动　；参考：《重庆交通大学》2014年硕士论文

【摘要】：随着我国对西部山区的建设和运输的发展，大量的载重货车要通过公路运输，而这些运输荷载远远超过了设计规范标准。再者，现有公路工程上广泛建造的钢筋混凝土梁桥由于长期超负荷营运，再加上其设计时并没有考虑桥梁车致振动对于桥梁寿命的影响，导致近年来桥梁因疲劳损伤而发生事故的惨剧屡见不鲜。因此，公路运输路线上的桥梁是否能满足我国交通运输发展的需要，载重货物车辆通过桥梁后桥梁整体和局部振动对既有桥梁的疲劳性能会产生多大的影响，这都是需要加倍关注的问题。本文旨在通过对钢筋混凝土简支梁桥在货车作用下的振动效应与疲劳性能的分析，提供结构振动加剧疲劳损伤的理论依据，揭示振动与疲劳的内部规律。参考近年来国内外学者在桥梁疲劳方面的研究成果，采用疲劳累积损伤理论对钢筋混凝土简支梁桥进行动力疲劳分析。具体内容有： ①通过静力应力变幅方法找出在汽车荷载作用下，桥梁的纵向的危险截面与应力相对较大的危险点。 ②通过实际交通量进行疲劳车模型的等效，利用统计学手段等效出了符合西部山区交通量的疲劳货车模型；通过车辆横向行驶位置的概率分析，以及各横向位置的桥梁挠度分析，找出最符合实际状态的横向分布特点。 ③本文通过钢筋混凝土桥梁的纵向疲劳车动态加载分析，总结了疲劳车作用下，桥梁动态响应的纵向分布规律与疲劳性能的宏观规律，并在此基础上分析了有限元振动分析的局限性和可参考性。 ④利用通用软件ANSYS实现了钢筋混凝土桥梁在等效疲劳车动力加载情况下的应力响应分析，探究了结构疲劳性能与结构振动的内在关系。 ⑤根据钢筋混凝土桥梁在疲劳车动力加载情况下的动应力响应谱，对钢筋混凝土简支梁桥各个疲劳关键点的疲劳性能进行了计算与评估。
[Abstract]:With the development of the construction and transportation in the western mountainous area of our country, a large number of heavy trucks have to be transported by road, and these transport loads far exceed the standard of design code.Furthermore, the existing reinforced concrete beam bridges, which are widely built on existing highway projects, are operated because of long-term overloading, and their design does not take into account the impact of bridge vehicle-induced vibration on the bridge life.In recent years, bridge accidents caused by fatigue damage are common.Therefore, whether the bridge on the highway transportation route can meet the needs of the development of transportation in our country, how much the whole and local vibration of the bridge after the vehicle passing through the bridge will affect the fatigue performance of the existing bridge?These are issues that require more attention.Through the analysis of the vibration effect and fatigue performance of reinforced concrete simply supported beam bridge under the action of freight car, this paper aims to provide the theoretical basis for the structural vibration to aggravate the fatigue damage, and to reveal the internal law of vibration and fatigue.Referring to the research results of bridge fatigue at home and abroad in recent years, the fatigue cumulative damage theory is used to analyze the dynamic fatigue of reinforced concrete simply supported beam bridge.Specific elements include:The main results are as follows: (1) by means of static stress amplitude variation method, the dangerous cross section of the bridge longitudinal and the dangerous point with relatively large stress are found under the action of automobile load.(2) the fatigue vehicle model is equivalent through the actual traffic volume, the fatigue truck model is equivalent to the traffic volume in the western mountainous area by statistical means, and the probability analysis of the vehicle's lateral driving position is given.And the deflection analysis of each lateral position of the bridge, find out the most suitable for the actual state of the transverse distribution characteristics.Through the dynamic analysis of longitudinal fatigue vehicle of reinforced concrete bridge, the longitudinal distribution law of dynamic response and the macroscopic law of fatigue performance of bridge under the action of fatigue vehicle are summarized in this paper.On this basis, the limitations and referential properties of finite element vibration analysis are analyzed.(4) the stress response analysis of reinforced concrete bridges under the dynamic loading of equivalent fatigue vehicle is realized by using the general software ANSYS, and the internal relationship between the fatigue performance of the structure and the structural vibration is explored.5. According to the dynamic stress response spectrum of reinforced concrete bridge under dynamic loading, the fatigue performance of each fatigue key point of reinforced concrete simply supported beam bridge is calculated and evaluated.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U441.3

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