【作者】 逄焕平；

【导师】 王建国；

【作者基本信息】 合肥工业大学 ， 结构工程， 2010， 博士

【摘要】 桥梁作为重要的社会基础设施,是抗振防灾研究的重要对象。尤其是大跨度的悬索桥,由于其特殊的重要地位,其车桥耦合动力特性更是我们需要重点研究的课题。近年来,随着世界经济的发展、技术的进步,高速铁路已经成为世界上最经济、最高效的运输系统。随着车辆行驶速度的提高,车辆与桥梁之间的动力相互作用问题更加的突出,车桥耦合动力相互作用对桥梁及车辆的影响越来越大。之前也有很多学者对这个问题进行了研究,给出了很多的解决方法,但是大都计算复杂,对各种桥型不具有通用性。因此,建立一套通用性好、精度高且使用方便的计算程序具有重大意义。本文针对目前其它计算方法的不足,在总结和吸收国内外前人研究成果的基础上,针对大跨度悬索桥在移动车辆作用下的车桥耦合振动问题进行了研究。给出了系统的求解车桥耦合振动问题的处理方法,并且对大跨度悬索桥的静力及成桥状态计算给出了详细的计算方法,并编制了相关的程序。本文主要研究内容包括:(1)对大跨度悬索桥的静力计算问题进行了讨论。本文基于挠度理论对悬索桥的静力计算方法进行了推导,在推导过程中考虑了活载二阶非线性项的影响,并验证了算法的正确性。在文中,对加劲梁在主塔处铰接和连续时受温度荷载的影响情况进行了对比研究。(2)给出了大跨度悬索桥成桥状态的精细化非线性有限元计算方法。本文首先对目前存在的几种确定成桥状态的解析方法进行了回顾,随后推导了基于非线性悬链线索单元的非线性有限元法的计算程式,并给出了详细的计算过程。在文中,采用多个经典算例验证了算法的有效性,并对某跨长江悬索桥的成桥状态进行了计算分析。(3)对简支梁的经典车桥耦合振动理论进行了回顾。对简支梁在移动力、移动质量、移动单轴车辆、移动双轴车辆作用下的解析计算方法进行了回顾。(4)对车辆和桥梁动力模型的建立方法进行了详细的研究。文中首先对车辆的基本要素进行了介绍,特别是对刚性连接的处理进行了说明,给出了任意复杂车辆模型的建立方法,并建立了双轴车辆和四轴车辆的动力模型。文中还对大跨度悬索桥动力模型的建立进行了说明。(5)基于随机理论,给出了路面平整度的模拟方法。文中对几种常见的路面平整度的功率谱密度进行了介绍,给出了基于谐波叠加法模拟路面平整度的计算方法。文中对空间频率范围的取值、取样周期的大小及取样时间步长的确定进行了说明,并给出了详细的计算步骤。最后对几种常见等级路面的路面平整度进行了模拟,并对模拟路面平整度的功率谱与理论功率谱进行了对比验证。(6)推导了车桥耦合单元,建立了车桥耦合振动的计算方法。本文推导了一般车辆作用下车桥耦合单元,对车桥耦合方程的建立及求解进行了详细的说明。文中还给出了移动质量、移动单轴车辆、移动双轴车辆及移动四轴车辆作用下的车桥耦合单元的影响矩阵。最后验证了本文方法的有效性并对某跨长江悬索桥在移动卡车、移动列车作用下的动力响应进行了求解。(7)给出了地震作用下的车桥耦合振动问题的计算方法。本文对地震作用下的车桥耦合振动方程进行了推导,并对某跨长江悬索桥在地震作用下的车桥耦合振动问题进行了研究。更多还原

【Abstract】 As the important infrastructure, bridge is the important subject investigated of the vibration reduction and disaster resistance. Since the long span suspension bridges play an important role, the dynamic characteristics of the coupling interaction between vehicle and bridge is an important research subject needs to pay more attention.Recently, with the development of the world economy and technical advancement, the high speed railway becomes the most economic and the most efficiency transport system in the world. With the increasing of the running speed of the vehicles, the VBI problem (the coupling interaction problem between the vehicles and bridges) becomes more serious. In the past, great deal research on the VBI problem was conducted and many solution methods were provided. But most of the solution methods are very complicated and don’t have versatility for various bridge types. So it has great significance to develop a program, which has good versatility and high precision.In this dissertation, considering the shortage of the other methods, the VBI problem of the long span suspension bridges under moving vehicles was studied based on the summary of general study of the predecessor’s research experience in China and abroad in this field. A method was provided to deal with the VBI problem, and detailed calculating methods were provided to calculate the static characteristics and determine the target configurations under dead loads for the long span suspension bridges. The main research work is as follows:1. The static calculation problem of long span suspension bridges was discussed. In this dissertation, the static calculation method of suspension bridges based on the deflection theory was derived. The second order nonlinear term of the live load was considered in this paper, and the validity was verified. Finally, the comparative study of stiffening girders continuous or hinged at the pylons under temperature load was made.2. The refined nonlinear finite element method was provided to determine the target configurations under dead loads for the long span suspension bridges. In this dissertation, several analytic methods of determining the target configurations were reviewed firstly, and then nonlinear finite element method based on the nonlinear catenary cable element were derived. The detailed calculating procedure was provided. In this paper, several classical examples were adopted to verify the validity of this method, and the target configuration of a suspension bridge crossing the Changjiang River was studied.3. The classical VBI theories for simply supported beam were reviewed. The analytic calculation methods were reviewed for simply supported beam under moving force, moving mass, moving single axle vehicle and moving double axle vehicle.4. Detailed research on modeling the vehicle and the bridge was made. Firstly, the fundamental elements of vehicles were introduced. Especially, the method dealing with the rigid connections was illuminated. And the modeling method for arbitrary complex vehicle was provided. The dynamic models were built for double axle vehicle and four-axis vehicle. The method building the dynamic model of long span suspension bridges was also introduced.5. The simulation method for road roughness was provided based on the stochastic theory. In this dissertation, several common power spectral density expressions for road roughness were introduced, and the simulation method was provided based on the harmonic superposition. The method to determine the range of spatial frequency, the sampling period and the sampling time step was introduced. At last, simulation was made for several common grade of road pavement, and the power spectrum estimation was compared with the theoretical power spectrum.6. The VBI element was derived, and a method calculating the VBI characteristics was built. The VBI element subjected to moving general vehicles was derived. The method of establishing the VBI equations and solution procedure were detailed introduced. In this dissertation, the influence matrices of VBI element under moving mass, moving single axle vehicle, moving double axle vehicle and moving four-axis vehicle. At last, the validity of this method was verified, and the dynamic response of a suspension bridge crossing the Changjiang River under moving trailer vehicle and train was solved.7. A method of solving VBI problem under seismic action was provided. In this dissertation, the vibration differential equations of the VBI problem were derived, and the VBI problem of a suspension bridge crossing the Changjiang River under seismic action was studied.更多还原