钢桁架桥的列车—桥梁耦合振动研究

发布时间：2018-06-03 23:38

本文选题：车桥耦合振动 + 动力响应　；参考：《山东科技大学》2017年硕士论文

【摘要】：近几十年来,随着科学技术水平的不断提高,人类社会快速发展,高速铁路系统得到迅猛发展,铁路线路中的桥梁数量随之增多,车辆的安全运行与桥梁的合理设计逐渐受到重视。当车辆以一定的速度驶过桥梁时,会引起桥梁结构的振动,反之,桥梁的振动作用于车辆,又会影响车辆的振动,这样,桥梁与桥上车辆便构成了一个相互作用的系统,研究这个系统对车、桥的安全性是有必要的。本文分别通过理论研究、缩尺模型试验和数值模型分析,对车桥耦合振动系统,但主要对桥梁子系统做了如下一些研究。(1)在做出一些假设的条件下,建立了 42自由度的列车空间多刚体动力学模型和桥梁的有限元模型,通过线性蠕滑理论和Hertz线性化理论建立了轮轨接触模型,使用Newmark-β法进行计算求解,通过其解的讨论,得出通过减小时间步长的方法使其解收敛的方法;(2)以德龙烟线线路德州至大家洼段铁路中一座64m单线铁路钢桁架桥为原型,自制1:48桥梁缩尺模型,用试验的方法测量了桥梁的弹性模量和固有自振频率。通过桥梁的动力试验,控制列车模型过桥的速度,采集桥梁位移与加速度数据,初步得出桥梁的动力响应随车辆过桥速度的增快而增大的结果;(3)使用有限元ANSYS软件对上述桥梁建立有限元模型,首先与相应的试验数据做比对,得到合理的有限元模型,之后用此模型做一些参数分析,发现桥梁动力响应并非完全随车速的增快而增大,并分析了其原因。接着进行了参数分析,并得到以下结论:在一定范围内,桥梁动力响应随弹性模量的增大而减小,超出此范围时,桥梁动力响应受弹性模量的影响甚微;阻尼比越大,桥梁的动力响应值越小,但阻尼比对桥梁动力响应影响程度较小;在弹性变形范围内,桥梁动力响应与列车荷载呈线性增长趋势;当列车总长度小于桥梁跨度时,桥梁动力响应随列车车厢数量的增加而增大,当列车总长度大于桥梁跨度时,桥梁动力响应增量将趋于平缓。(4)根据参数分析得出的结论,针对这些参数,提出了一些列车安全行驶和保证桥梁结构安全的措施,例如:合理选用钢材,防止列车超载,设置阻尼器等方法,对桥梁实际工程与设计具有一定参考价值。
[Abstract]:In recent decades, with the development of science and technology, the rapid development of human society, the rapid development of high-speed railway system, the number of bridges in railway lines has increased. The safe operation of vehicles and the reasonable design of bridges have been paid more and more attention. When a vehicle passes a bridge at a certain speed, it will cause the vibration of the bridge structure. On the contrary, the vibration of the bridge acts on the vehicle, which will affect the vibration of the vehicle. In this way, the bridge and the vehicle on the bridge will form an interactive system. It is necessary to study the safety of this system for vehicles and bridges. In this paper, through theoretical research, scale model test and numerical model analysis, the vehicle-bridge coupling vibration system is studied respectively, but the bridge subsystem is mainly studied as follows. 1) under some hypothetical conditions, A 42-DOF multi-rigid body dynamics model in train space and a finite element model of bridge are established. The wheel-rail contact model is established by linear creep theory and Hertz linearization theory, and is solved by Newmark- 尾 method. It is concluded that the solution converges by reducing the time step size.) taking a 64m single-track railway steel truss bridge in the Dezhou to Dajiawa railway line as the prototype, the 1:48 bridge scale model is made. The elastic modulus and natural vibration frequency of the bridge are measured by means of experiments. Through the dynamic test of the bridge, the speed of the train model crossing the bridge is controlled, and the displacement and acceleration data of the bridge are collected. The results show that the dynamic response of the bridge increases with the increase of the speed of the vehicle crossing the bridge. The finite element model of the bridge is established by using the finite element ANSYS software. At first, a reasonable finite element model is obtained by comparing with the corresponding experimental data. By using this model, it is found that the dynamic response of the bridge does not increase completely with the increase of speed, and the reasons are analyzed. Then the parameter analysis is carried out, and the following conclusions are obtained: in a certain range, the dynamic response of the bridge decreases with the increase of the elastic modulus, beyond which the dynamic response of the bridge is little affected by the elastic modulus, and the damping ratio is larger. The smaller the dynamic response of the bridge is, the smaller the influence of the damping ratio on the dynamic response of the bridge is. In the elastic deformation range, the dynamic response of the bridge and the train load are linearly increasing; when the total length of the train is less than the span of the bridge, The dynamic response of the bridge increases with the increase of the number of train compartments. When the total length of the train is larger than the span of the bridge, the increment of the dynamic response of the bridge will tend to be flat. Some measures for safe running of trains and safety of bridge structures are put forward, such as reasonable selection of steel, prevention of train overload, installation of dampers and so on, which have certain reference value for practical engineering and design of bridges.
【学位授予单位】：山东科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U441.3;U211.3

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