刹车行为对大跨度悬索桥的振动分析

发布时间：2018-01-12 18:43

本文关键词：刹车行为对大跨度悬索桥的振动分析　出处：《重庆交通大学》2014年硕士论文　论文类型：学位论文

【摘要】：国民经济的飞速发展促使了客运与货运量日趋增长,高速路网的全面覆盖使得行车速度、车流密度和载重量都有大幅度的提高，国家积极推广使用新型高强材料使得桥梁结构的设计与施工正朝着更大、更细、更柔的方向发展。车辆因交通事故，恶劣天气等原因而突然刹车的现象时有发生，上述四个方面的原因造成了制动力对悬索桥的振动效应变得更加明显。因此，揭示车桥振动机理，展开制动力对悬索桥的振动分析，对悬索桥的设计、建设、维护工作都具有极为重要的理论意义。回顾前人做出的努力，可见车-桥耦合动力学问题已取得了丰硕的研究成果。基于时域的车桥耦合振动分析方法是比较常用的方法，按照求解过程大致可以分为三大类： ①分离迭代法，力学概念明确，分开求解车辆桥方程，避免了车辆和桥梁两个振动方程之间复杂耦合关系的处理，但是可能存在迭代不收敛的情况。 ②约束方程分析法，以通用有限元软件为工具，直接建立车辆和桥梁模型，分析计算时只需改变车桥耦合点，但Rayleigh阻尼中多考虑了车辆的质量和刚度矩阵的参与，计算结果存在偏差。 ③联合方程分析法，消除了约束方程分析法中阻尼考虑不准确的影响，将车桥平衡方程进行解耦，直接整体求解，但计算之前需要处理车辆和桥梁之间复杂的耦合关系，对于空间车桥耦合振动问题的分析，难度较大。在前人的研究成果基础上，结合青草背长江大桥进行了如下工作： ①车辆采用7自由度平面分析模型，利用D.Alembert原理推导车辆动力平衡方程，，桥梁则直接利用Ansys建立有限元分析模型，车桥耦合效应通过车轮与桥面接触点的几何条件和静力平衡条件来联系。 ②利用Runge-Kutta法在Ansys中编写车辆动力平衡方程求解程序，拟定合理的时间积分步长，采用Ansys的瞬态动力学求解器求解桥梁方程。根据现有文献算例，验证计算程序的正确性。 ③结合04规范与89规范荷载的特点，采用静力等效计算原则，确定车流分布情况，利用谐波合成法对路面不平整进行模拟。 ④对实例工程青草背长江大桥进行车桥耦合分析计算，分析行车速度，桥面不平顺，刹车制动三种因素影响下的动力响应。
[Abstract]:With the rapid development of the national economy, the passenger and freight traffic volume is increasing day by day, and the overall coverage of the highway network makes the speed, traffic density and load weight greatly increased. The country actively promotes the use of new high-strength materials to make the design and construction of bridge structures moving towards a larger, finer and softer direction. The phenomenon of sudden braking occurs from time to time due to bad weather and other reasons. The above four reasons cause the vibration effect of braking force to the suspension bridge become more obvious. Therefore, the vibration mechanism of vehicle and bridge is revealed. It is of great theoretical significance for the design, construction and maintenance of suspension bridge to carry out the vibration analysis of suspension bridge with braking force. Looking back on the previous efforts, we can see that the vehicle-bridge coupling dynamics problem has made a lot of research results. The time-domain vehicle-bridge coupling vibration analysis method is a more common method. According to the solution process, it can be divided into three categories: 1. The separation iteration method, the mechanics concept is clear, solves the vehicle bridge equation separately, avoids the complex coupling relation processing between the vehicle and the bridge two vibration equations, but may have the iteration not to converge the situation. (2) the constraint equation analysis method, with the general finite element software as the tool, establishes the vehicle and the bridge model directly, only needs to change the vehicle-bridge coupling point in the analysis calculation. However, the mass and stiffness matrix of the vehicle are often considered in the Rayleigh damping, and the calculation results are deviated. (3) the joint equation analysis method eliminates the influence of inaccurate damping consideration in the constraint equation analysis method, and decouples the vehicle-bridge equilibrium equation and solves it directly as a whole. But it is necessary to deal with the complicated coupling relationship between vehicle and bridge before calculation, so it is difficult to analyze the coupling vibration of space vehicle-bridge. On the basis of the previous research results, the following work has been done in combination with the Qingcao back Yangtze River Bridge: (1) the vehicle adopts the plane analysis model of 7 degrees of freedom, the dynamic equilibrium equation of the vehicle is derived by the D. Alembert principle, and the finite element analysis model of the bridge is established directly by using Ansys. The coupling effect of vehicle and bridge is connected by the geometric condition and static equilibrium condition of the contact point between the wheel and the bridge deck. (2) the Runge-Kutta method is used to program the solution of vehicle dynamic balance equation in Ansys, and the reasonable time integral step is worked out. The transient dynamic solver of Ansys is used to solve the bridge equation. (3) combined with the characteristics of load in Code 04 and Code 89, the distribution of vehicle flow is determined by using the principle of static equivalent calculation, and the uneven road surface is simulated by harmonic synthesis method. (4) the vehicle-bridge coupling analysis of Qingcaobei Yangtze River Bridge is carried out, and the dynamic response under the influence of driving speed, uneven deck and brake braking is analyzed.
【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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