风和列车荷载作用下大跨桥梁动力分析

发布时间：2018-07-09 18:33

本文选题：大跨度桥梁 + 风荷载　；参考：《湘潭大学》2014年硕士论文

【摘要】：随着经济的快速发展，我国铁路建设也迎来了建设高峰期，大跨度的铁路桥梁也出现得越来越多，这其中不乏建设在较深的江河湖海和山区峡谷当中。因大跨度桥梁属于比较柔的结构，故此时必须考虑风和列车荷载对桥梁的共同作用来保障桥梁的稳定性和列车行驶过程中的安全性。本文即是针对此复杂的风-车-桥系统，采取自主编程加有限元软件的方法来求解此耦合振动的系统，得出风和列车荷载共同作用下大跨度桥梁的动力响应。本文主要工作如下： 1.概述了国内外大跨度桥梁的发展情况，统计了当前不同类型的主跨前十的大跨度桥梁。分别概述了风致桥梁振动的发展、列车空气动力学的研究成果以及车桥耦合振动的研究。最后总结风荷载作用下车桥系统研究，即对风-车-桥系统耦合振动研究的特点，从中引出本文的选题依据及研究思路。 2.介绍风-车-桥系统的三个组成部分。自然风的平均成分和脉动成分的基本特性；建立考虑车体、转向架、轮对各方向自由度的车辆动力学模型；简单总结了桥梁有限元分析的基本理论和常用的桥梁有限元模型。 3.根据随机振动理论并结合matlab进行自主编程来模拟自然风的脉动特性，得出模拟点的脉动风速时程曲线并进行相关验证，然后将其转换成桥梁的风荷载。根据蠕滑理论并结合matlab进行自主编程，将行驶在桥梁上的不同类型的动车组通过轮轨相互作用关系求解转换成为桥梁的外荷载，并与相关实验结果进行对比来验证轮轨力程序的准确性。 4.首先考虑在无风荷载的情况下，将模拟的轮轨力输入到采用midas Civil建立的桥梁有限元分析模型中来求解桥梁的动力响应，并验证此种求解车桥系统耦合振动的分析方法的可行性。其次再将模拟的风荷载作为外部荷载输入至车桥系统中，建立风-车-桥系统模型，推导此系统的振动运动方程并介绍其求解方法。 5.以大跨度连续刚构桥、拱桥和斜拉-悬索桥作为算例，求解计算桥梁结构在风荷载和和谐号CRH1、CRH2、CRH3和CRH5型电力动车组等列车荷载同时作用的情况下的动力响应曲线。其主要的研究内容有桥梁特征值的分析、风速、风攻角及车速变化对桥梁振动响应的影响等内容。结果表明： (a)风荷载对大跨度桥梁的的横向位移和横向加速度有较大影响，对竖向位移和竖向加速度影响不大； (b)大跨度桥梁跨中的竖向位移和竖向加速度随风荷载的增加而增加，但是其时程曲线的变化趋势基本不变； (c)当无风荷载时，，随着车速的变化，大跨度桥梁的各向位移及加速度均有一定影响，但其对横向位移和横向加速度的影响幅度远不如风荷载明显。 (d)当车速、风速或风攻角变化时，桥梁跨中截面的动力响应值较其他截面的值大。
[Abstract]:With the rapid development of economy, railway construction in our country has ushered in the peak period of construction, and there are more and more long-span railway bridges, many of which are built in deep rivers, lakes, seas and mountain canyons. Because the long-span bridge belongs to the softer structure, it is necessary to consider the joint action of wind and train load on the bridge to ensure the stability of the bridge and the safety during the train running. In this paper, for this complicated wind-vehicle-bridge system, the method of self-programming and finite element software is adopted to solve the coupled vibration system, and the dynamic response of the long-span bridge under the combined action of wind and train load is obtained. The main work of this paper is as follows: 1. The development of long span bridges at home and abroad is summarized, and different types of long span bridges with the top ten main spans are counted. The development of wind-induced bridge vibration, the research results of train aerodynamics and the research of vehicle-bridge coupling vibration are summarized respectively. Finally, the paper summarizes the characteristics of the research on the wind-bridge system under the wind load, which is the characteristics of the wind-vehicle-bridge system coupling vibration research, and leads to the basis and research ideas of this paper. 2. This paper introduces three components of wind-vehicle-bridge system. The basic characteristics of the average component and pulsating component of natural wind, the vehicle dynamics model considering the freedom of vehicle body, bogie and wheelset is established. The basic theory of bridge finite element analysis and the commonly used bridge finite element model are briefly summarized. Based on the random vibration theory and matlab, the pulsation characteristic of natural wind is simulated, and the time history curve of the wind velocity at the simulation point is obtained and verified. Then it is converted into the wind load of the bridge. According to creep theory and matlab, the different types of EMU running on the bridge are solved by wheel-rail interaction relationship and converted into the external load of the bridge. And compared with the experimental results to verify the accuracy of wheel-rail force program. 4. Firstly, in the case of no wind load, the simulated wheel-rail force is input into the bridge finite element analysis model established by midas Civil to solve the dynamic response of the bridge, and the feasibility of this method for solving the coupled vibration of the vehicle-bridge system is verified. Secondly, the simulated wind load is input into the vehicle-bridge system as the external load, the model of the wind-vehicle-bridge system is established, the vibration equation of the system is deduced and the solution method is introduced. Taking long-span continuous rigid frame bridge, arch bridge and cable-stayed suspension bridge as examples, the dynamic response curves of bridge structure under wind load and train loads such as CRH1 / CRH2 / CRH3 and CRH5 electric EMU are calculated. The main research contents include the analysis of bridge eigenvalue, the influence of wind speed, wind attack angle and speed on the bridge vibration response. The results show that the (a) wind load has great influence on the lateral displacement and lateral acceleration of the long-span bridge, but has little effect on the vertical displacement and the vertical acceleration. The vertical displacement and acceleration in the span of (b) long-span bridge increase with the increase of wind load, but the change trend of time-history curve is basically unchanged when there is no wind load,; (c) changes with the speed of the bridge. Each direction displacement and acceleration of long-span bridge have certain influence, but its influence amplitude on transverse displacement and transverse acceleration is far less than. (d) when speed, wind speed or wind attack angle change obviously. The dynamic response of the middle section of the bridge is larger than that of the other sections.
【学位授予单位】：湘潭大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U441.3

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