高墩大跨桥梁车—桥耦合振动研究

发布时间：2018-04-07 19:03

本文选题：高墩大跨桥梁　切入点：车-桥耦合　出处：《兰州交通大学》2014年硕士论文

【摘要】：高墩大跨桥梁车-桥系统耦合振动主要体现在两个方面：一是高墩大跨铁路桥梁在高速、重载列车作用下的动力响应问题,二是桥上列车运行的安全性与平稳性问题。本文以纵目沟特大桥为工程背景进行高墩大跨桥梁车-桥耦合振动分析研究。该桥主跨结构形式为(78+2×136+78)m预应力混凝土变截面连续刚构,4#、6#墩采用双薄壁墩,墩高均为48m；5#墩采用新型柱板式空心高墩,墩高为105m。在搜集、整理高墩大跨桥梁车-桥耦合振动研究的相关资料和文献的基础上,建立了31个自由度的四轴车辆动力分析模型,利用达朗贝尔原理推导了车辆的动力学方程。借助ANSYS软件建立了纵目沟特大桥的三维空间有限元分析模型,采用模态综合法对其动力特性(频率和振型)进行分析计算,并结合相应规范对其自振频率计算结果进行评估。结合国内外车辆系统、桥梁结构相关规范以及试验研究成果,建立了车-桥耦合系统动力响应分析评价体系。通过ANSYS-UM.EXE程序将ANSYS建立的三维桥梁模型导入UM(Universal Mechanism)软件,并与UM软件建立的车辆模型进行恰当连接,以轨道不平顺和轮对蛇形波作为车-桥耦合振动系统的激励源,建立了纵目沟特大桥车-桥耦合振动仿真分析整体模型,通过联合仿真技术实现了高墩大跨桥梁车-桥耦合振动研究。对不同车辆(机车、客车以及货车)的运行稳定性进行了分析,求解了非线性临界速度；分析了单个机车、编组客车以及编组货车(重载)在设计时速下通过桥梁时,桥梁结构以及车辆系统的动力响应；并在此基础上探讨了桥梁结构刚度、行车速度、轨道不平顺以及货车编组情况等因素对高墩大跨桥梁车-桥耦合系统振动的影响。由本文研究成果可以得出：纵目沟特大桥的前10阶振型以横桥向贡献为主,说明桥梁横向刚度相对较小；客车以及重载货车以设计时速过桥时,车辆系统和桥梁结构的各项动力响应指标均在规范限值以内；桥梁横向刚度(主梁横向刚度以及桥墩横向刚度)的减小对车-桥耦合系统的横向振动影响比较明显,对其竖向振动影响较小；主梁竖向刚度的改变对车-桥耦合系统的竖向振动影响较为显著,对其横向振动影响较小；车辆以及桥梁结构的各项动力响应指标总体上随着行车速度的增加而增大；轨道不平顺的增加导致车-桥耦合系统振动明显加剧,说明轨道不平顺是车-桥耦合系统的主要激励源之一；空载货车的横向稳定性较重载货车的横向稳定性弱,易发生脱轨事故。
[Abstract]:The coupling vibration of vehicle-bridge system with high piers and long span bridges is mainly reflected in two aspects: one is the dynamic response of railway bridges with high piers and long span under the action of high-speed and heavy haul trains, the other is the safety and stability of train running on the bridge.In this paper, the vehicle-bridge coupling vibration analysis of long span bridge with high piers is carried out under the background of Longmugou Bridge.The main span structure of the bridge is composed of two thin-walled piers with continuous rigid frame with variable cross-section and continuous rigid frame with variable cross-section. The height of piers is 48m, and the height of piers is 105m.On the basis of collecting and arranging the related data and literature of the vehicle-bridge coupling vibration research of long-span bridges with high piers, a dynamic analysis model of 31 degrees of freedom four-axis vehicles is established, and the dynamic equations of the vehicles are derived by using the Darembert principle.The three-dimensional finite element analysis model of Longmugou Bridge is established with the help of ANSYS software. The dynamic characteristics (frequency and mode shape) of the bridge are analyzed and calculated by modal synthesis method, and the calculation results of the natural vibration frequency are evaluated with the corresponding specifications.The dynamic response analysis and evaluation system of vehicle-bridge coupling system is established based on the related codes of vehicle system, bridge structure and experimental research results at home and abroad.The 3D bridge model established by ANSYS is imported into UM(Universal Mechanism software by ANSYS-UM.EXE program, and it is properly connected with the vehicle model established by UM software. The track irregularity and the serpentine wave of wheelset are used as the excitation source of the vehicle-bridge coupling vibration system.The whole model of vehicle-bridge coupling vibration analysis for Longmugou large bridge is established, and the vehicle-bridge coupling vibration of long span bridge with high piers is studied by combined simulation technology.The operation stability of different rolling stock (locomotives, passenger cars and freight cars) is analyzed, and the nonlinear critical velocity is solved.Based on the dynamic response of bridge structure and vehicle system, the effects of stiffness of bridge structure, driving speed, track irregularity and truck marshalling on the vibration of vehicle-bridge coupling system with high piers and large span bridges are discussed.From the research results of this paper, it can be concluded that the first 10 vibration modes of Longmugou Bridge are mainly the contribution of transverse bridge, which shows that the lateral stiffness of the bridge is relatively small, and that when passenger cars and heavy trucks cross the bridge with design speed,The change of vertical stiffness of the main beam has a significant effect on the vertical vibration of the vehicle-bridge coupling system, and has little effect on the transverse vibration.As a whole, the dynamic response indexes of vehicle and bridge structure increase with the increase of driving speed, and the vibration of vehicle-bridge coupling system increases obviously with the increase of track irregularity.It is shown that track irregularity is one of the main excitation sources of vehicle-bridge coupling system, and that the lateral stability of empty truck is weaker than that of heavy truck, and it is easy to derail.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U441.3

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