风-车-桥耦合振动研究

发布时间：2018-01-23 04:50

本文关键词： 大跨悬索桥抖振气动导纳风速谱风-车-桥耦合　出处：《重庆大学》2015年硕士论文　论文类型：学位论文

【摘要】：风-车-桥的空间耦合振动的本质可理解为:风与车的相互作用,车与桥的相互作用、风与桥的流固耦合以及此三者之间的相互作用。影响其相互间作用的主要因素有风的自然界属性、桥梁的动力特性及车辆的振动性能。要搞清楚其相互作用,必须得对其影响因素进行深入探究,故本文主要进行了以下几个方面的研究。对寸滩长江大桥桥址处风环境进行了长达一年的观测,将观测的时域风速数据进行快速离散傅里叶变换,得到其风速谱值,对其谱值进行最小二乘法拟合,获得符合桥址处风环境的风谱函数。根据所获得的脉动风速谱函数基于改进的谐波合成法开发了三维脉动风场模拟程序SWFCMN,利用该程序,获得了主梁每个节点的竖向和水平向脉动风速时程序列。进行了寸滩大桥宽体箱梁节段模型风洞实验,获得三分力系数,根据实验测得的风速和抖振力进行快速离散傅里叶变换,获得风速谱和力谱,进而依据该值拟合出气动导纳函数。建立了常见车辆的振动力学模型,分析了桥梁对路面的激励,研究表明该激励可以按综合为路面粗糙度来考虑,给出了综合路面粗糙度的概念。基于MATLAB平台开发了模拟路面平整度的程序LMPZD,采用该程序模拟了A、B、C三种路面粗糙度,并与其谱值进行了对比,结果完全吻合。在此基础上给出了分离迭代法计算车桥耦合的原理,及其二者边界协调条件。介绍了基于分离迭代法计算风-车-桥耦合的程序开发手段,基于开放的ansys二次开发平台APDL,依据分离迭代法原理开发了风-车-桥耦合计算程序,该程序用常规的ansys建立桥梁计算模型,利用APDL编程形成车辆的刚度、质量、阻尼,荷载矩阵,并采用Newmark法进行车辆动力方程的求解。介绍的风-车-桥耦合振动的应用之一,评价行车安安性。建立了评价行车安全的三种事故模型,给出了寸滩长江大桥极端天气车辆管制的临界参考风速。桥梁抖振响应的计算结果表明:气动导纳函数对抖振力的影响很大,考虑非线性和不考虑非线性结果差别也很显著,这说明大跨度悬索桥的柔度大,其非线性影响不可忽略。风-车-桥的计算表明,不同车辆其气动性能完全不同,发生安全事故的临界风速有显著差别。
[Abstract]:The nature of the spatial coupling vibration of wind-vehicle-bridge can be understood as the interaction between wind and vehicle, and the interaction between vehicle and bridge. The fluid-solid coupling between wind and bridge and the interaction between them. The main factors influencing the interaction are the natural properties of wind, the dynamic characteristics of bridges and the vibration performance of vehicles. It is necessary to find out the interaction between wind and bridge. Must carry on the thorough research to its influence factor, therefore this article has mainly carried on the following several aspects research, has carried on the observation as long as one year to the Cutan Changjiang River bridge site wind environment. The time-domain wind speed data are analyzed by fast discrete Fourier transform (FFT), and the spectral values are fitted by least square method. According to the wind spectrum function obtained from the wind environment at the bridge site, based on the improved harmonic synthesis method, a three-dimensional wind field simulation program SWFCMN is developed. The vertical and horizontal pulsating wind velocities of each node of the main girder are obtained, and the wind tunnel experiments of the section model of the wide body box girder of the Putan Bridge are carried out, and the three-point force coefficient is obtained. According to the measured wind speed and buffeting force, the fast discrete Fourier transform is carried out to obtain the wind speed spectrum and the force spectrum, and then the aerodynamic admittance function is fitted according to this value, and the vibration mechanics model of common vehicles is established. The excitation of the bridge to the road surface is analyzed, and the research shows that the excitation can be considered according to the road roughness. This paper presents the concept of comprehensive road roughness. Based on MATLAB platform, a program LMPZD is developed to simulate the roughness of road surface. The program is used to simulate three kinds of roughness of road surface. The results are in good agreement with their spectral values. On this basis, the principle of calculating vehicle-bridge coupling by separating iterative method is given. This paper introduces the program development method based on the separated iteration method to calculate the wind-vehicle-bridge coupling and the APDL based on the open ansys secondary development platform. The wind-vehicle-bridge coupling calculation program is developed according to the principle of separated iteration method. The routine ansys is used to establish the bridge calculation model and the APDL program is used to form the stiffness, mass and damping of the vehicle. The load matrix and the Newmark method are used to solve the vehicle dynamic equation. One of the applications of the wind-vehicle-bridge coupling vibration is introduced. Three accident models are established to evaluate traffic safety. The critical reference wind speed of vehicle control in extreme weather is given. The calculated results of the bridge buffeting response show that the aerodynamic admittance function has a great influence on the buffeting force. The difference between considering the nonlinear and not considering the nonlinear results is significant, which shows that the flexibility of the long-span suspension bridge is large, and the nonlinear effect can not be ignored. The calculation of the wind-vehicle-bridge shows that. The aerodynamic performance of different vehicles is completely different, and the critical wind speed of safety accidents is significantly different.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U441.3

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