【作者】 刘海涛；

【导师】 郭文华；

【作者基本信息】 中南大学 ， 桥梁与隧道工程， 2011， 博士

【摘要】 风-列车-汽车-桥梁耦合振动的研究对行车安全与舒适、桥梁结构设计与养护具有十分重要的意义。本文的主要工作如下：1、完善了列车空气动力模型。列车简化为弹簧阻尼相连的多刚体体系。作用于列车上的风包括列车运动风和自然风。风对列车的气动力主要由风与列车相对速度的大小以及相关的列车气动系数等确定。而列车气动系数的确定,除了考虑列车本身外形及其附近桥梁断面形状的影响外,还与相对风与列车运行方向的偏转角(即风偏角)有关。相对风的大小可根据列车车速、平均风速及其该时刻该节列车车厢质心所对应主梁位置处的脉动风速来计算。2、建立了两种汽车空气动力模型。一种是“汽车接触点侧滑模型”,可模拟极短时间内突然风对桥上运行汽车的瞬时影响,适用于突然风作用下开展桥上汽车运行安全性评估；另一种是“汽车接触点非侧滑模型”,可模拟一定持续时间内在特定条件下自然风对桥上运行汽车的影响,适用于持续风作用下同时开展桥上汽车运行安全性、舒适性评估。这两种模型汽车分别采用了不同的自由度数,不同的汽车轮胎与桥面相互作用力模拟计算方法,但风对汽车气动力的模拟计算方法相同,而且均与风对列车气动力的模拟计算方法类似。3、分别建立了铁路桥梁、公路桥梁以及公铁两用桥的空气动力分析模型。桥梁结构本身采用空间有限单元来模拟,大跨桥梁可考虑几何非线性的影响。而风对桥梁的气动力主要包括静风力、抖振力和自激力,桥梁气动力的大小主要由平均风速、脉动风速及桥梁的气动系数等确定。而桥梁气动系数的确定,不仅与主梁断面本身形状有关,还需考虑梁上列车(或汽车)外形的影响。故计算主梁气动力时,对于主梁附近是否有车,采用了不同的气动系数。对于高墩大跨桥梁,还可同时考虑作用在主梁和高墩气动力的影响。对于脉动风速的模拟,可考虑不同水平位置及不同高度的空间相关性。4、提出了一种高效、实用的分析方法来建立风-汽车-列车-线路-桥梁时变系统的空间耦合振动方程。该方法易于计算机实施,可方便考虑不同类型汽车和列车、不同车流分布、列车的单双线行车、不同路面粗糙度、不同轨道不平顺、不同列车速度、不同汽车速度、不同自然风速等实际情况的影响。提出了相应的数值算法—“差分解耦法”和“预测-隐式积分法”,可精确高效的求解空间耦合振动方程,该方法在每一时间积分步内不需要迭代也不需要重新生成刚度、阻尼、质量矩阵。5、基于‘’Visual Fortran 6.5"编制了“风-汽车-列车-线路-桥梁”大型耦合计算"VSI" (Vehicle and Structure Interaction dynamic program)程序,该程序具有良好的通用性,可以模拟常见的不同类型的桥梁、汽车和列车。开展桥梁风致振动、桥梁动力特性、风-列车-桥梁耦合振动、风-汽车-桥梁耦合振动、风-汽车-列车-桥梁耦合振动等的计算。通过“残差监视”保证方程求解的精度,通过“车辆预警”实时监视车辆的运行状态。6、开展了风-高速列车-线路-简支梁耦合振动分析。以高速铁路32m简支梁为工程背景,建立了简支梁桥的有限元模型。然后开展了无风期间高速列车-线路-简支梁振动分析,主要探讨了列车车速、单双线行车等对车桥系统动力响应的影响,根据车桥动力响应计算结果和相关规范、标准对桥梁动力性能和高速列车运行安全性、舒适性进行了评估。接着开展了强风期间高速列车-线路-简支梁振动参数分析,探讨了列车车速、自然风速、轨道不平顺、车辆气动系数、桥梁气动系数等参数对车桥动力响应的影响。最后分别计算了四种不同平均风速下高速列车以不同车速通过多跨简支梁桥时的车桥动力响应,根据计算结果和相关规范标准,得到了确保列车安全舒适通过简支梁时对应的列车临界车速,提出了多风期间确保列车安全运营和桥梁正常使用的控制标准。7、研究了风-汽车-连续刚构桥耦合振动。建立了高墩大跨连续刚构桥——坪子上大桥的有限元模型。首先通过与一成熟软件计算结果对比,验证了本程序的可靠性。然后计算了无风时车速和单双线行车对车桥振动响应的影响。随后采用两种方法,研究了不同风速下汽车通过刚构桥的振动响应,根据建立的安全性和舒适性指标,对汽车进行了评估,进而确定了不同路面状况和行车速度下的临界风速。最后通过桥梁风致振动和风-车-桥耦合分析,探讨了风和汽车对桥梁振动响应的影响。8、开展了风-汽车-列车-公铁两用桥耦合振动分析。以重庆朝天门大桥为工程背景,建立了公铁两用桥有限元模型,计算了桥梁动力特性。然后分别开展了七种工况的仿真计算分析：公铁两用桥的风振分析、列车-公铁两用桥振动分析、风-列车-公铁两用桥振动分析、汽车-公铁两用桥振动分析、风-汽车-公铁两用桥振动分析、汽车-列车-公铁两用桥振动分析、风-汽车-列车-公铁两用桥振动分析。得到了不同工况下汽车、列车、公铁两用桥的最大空间振动响应及其时程曲线,并分别探讨了风、汽车和列车对桥梁动力响应的影响；风、汽车对列车振动响应的影响；风、列车对汽车振动响应的影响。最后对公轨两用桥的动力性能及强风作用下桥上列车、汽车运行安全性、舒适性进行了评估。计算结果表明：汽车对列车振动响应影响很小。列车使汽车的横向振动加大,但对汽车安全性影响很小。风对汽车和列车的竖向振动影响较小,增大汽车和列车的横向振动,增大汽车和列车的安全指标值,对行车不利。风、汽车和列车对桥梁振动响应均有显著影响。三者综合下使桥梁产生最大振动响应。更多还原

【Abstract】 The study on coupled wind-train-automobile-bridge system has great significance for running safety and riding comfort of vehicles, design and maintenance of bridge. The main contents and achievements of this paper are as following:1. Aerodynamic model of train is proposed. The train is idealized as a combination of a number of rigid bodies connected by a series of springs and dampers. The wind acting on the train composed of the wind generated by relative movement of train and atmosphere, mean wind and fluctuating wind. Aerodynamic forces expressed as aerodynamic coefficients and relative wind speed for train function. Aerodynamic coefficients consider the impact of bridge and wind yaw angle.2. Two types of aerodynamic models of automobile are presented. One is aerodynamic model of contact points with sideslip, which is used to analysis the coupled system under sudden wind. The other is aerodynamic model of contact points without sideslip, which can calculate the coupled system under normal wind. They are different in forces between car and road, model degree numbers and used conditions. The aerodynamic forces are calculated by the same way of the train model.3. Railway-bridge, highway-Bridge and highway-railway-bridge are modeled respectively. The bridge is represented by the conventional finite elements with geometric nonlinearity. Aerodynamic forces consist of mean wind, buffeting and self-excited aerodynamic forces. Aerodynamic coefficients of the bridge are different with vehicles or without vehicles. Three-dimensional fluctuating wind fields considering different heights are simulated.4. This paper presents an efficient and practical framework for dynamic analysis of coupled wind, train, automobile and bridge system in time domain. This method is easy to consider any general types of automobiles and trains, running modes, road roughness, track roughness, different speed of vehicles, different speed of natural wind and so on. As two types of new numerical algorithms, "difference-uncoupled method" and "predictor-implicit integration method" are proposed respectively, this can perfectly solve the equation. In each integration step, the solution need not iterate, the matrixes of equation need not reassembled.5. The associated computer program named as VSI are accordingly developed. The program can be used to study Wind-induced vibration of bridge, Dynamic behaviors of bridge, wind-train-bridge interaction, wind-car-bridge interaction, wind-road vehicle-train-bridge interaction and so on. Residual monitoring is used to ensure the accuracy of the solution. And safety monitoring is used to monitor the condition of vehicles.6. Dynamic performances of coupled wind-train-simply bridge system are calculated. The indictors of safety and riding comfort are established. The effects of the speed of the train and running model are discussed under windless. Meanwhile, dynamic behaviors of the bridge and running safety and comfort of trains are estimated according to relative indictors of safety and riding comfort. The effects of speed of the train, speed of the natural wind, rail roughness, aerodynamic characters of the train and aerodynamic characters of the bridge are studied. Finally dynamic performances of trains are calculated under different wind velocity. Then critical speeds of the train under any natural wind are fixed.7. Dynamic performances of coupled wind-automobile-continuous bridge are analyzed. First the VSI program is proved reliable by comparing with the calculation results of reliable software. Then the effects of the speed of the train and running model are discussed with windless. Meanwhile, the indictors of safety and riding comfort of the car are established. Dynamic performances, the safety and riding comfort of cars at any speed are studied. And critical speeds of natural wind are fixed. Finally the effects of the wind and vehicles to dynamic performances of bridge are analysis.8. Dynamic performances of coupled wind-automobile-train-bridge are studied. Chao-Tian-Men-bridge is modeled. Vibration characteristics are calculated by Ansys program and VSI program, and showed the same results. The mutual influences among automobiles, trains and bridges under natural wind are discussed. Wind induced vibration of highway-railway-bridge and dynamic performances of rail-bridge, wind-rail-bridge, automobile-bridge, wind-automobile-bridge, automobile-rail-bridge and wind-automobile-rail-bridge are calculated. The results show that automobiles have little influences on dynamic performances of trains, while, trains affect dynamic performances of automobile in lateral direction under natural wind. Wind, automobiles and trains have influences on the bridge.更多还原