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基于路面不平整度的高墩大跨连续梁桥冲击系数分析-车桥耦合

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摘要车辆以一定的速度通过桥梁结构时,由于车辆发动机震动、路面不平整等原因,桥梁会发生一定的振动,并且桥梁结构的这种由车辆引起的振动对车辆的行驶和振动会有一定的影响,那么它们两者之间的振动是相互影响相互关联的,这就是车桥耦合的一般定义即使在没有外力的作用下,该振动也有可能会激烈的发生车辆发动机的抖动、桥面的不平整等因素都会引起这种振动当两者的频率比接近1时就可能会造成车辆与桥梁的共振,这时桥梁的振动是非常剧烈的,进而桥梁结构遭到破坏,引发工程和交通事故一般情况我们从以下两个方面研究车桥耦合作用:一、行驶的车辆对桥梁冲击作用(冲击系数),该项对桥梁结构的安全有着重要的影响;二、在考虑路面不平整度的情况下乘客和驾驶员乘车的舒适性研究表明路面平整度越差,车辆的动力响应明显增大,桥梁的跨中的竖向位移、加速度响应和冲击系数都明显变大,因此作者基于这一考虑对公路桥涵设计通用规范(JTG D60-2004)中冲击系数的数学表达式进行了修正本文的研究为国家自然科学基金“随机车流作用下高墩大跨桥梁的振动特性及行车舒适性研究”(基金号:51108045);“风环境下车辆在公路及桥梁上安全行驶的可靠度评估、对策与管理系统”(基金号:51178066)的部分研究内容,本文中主要研究内容有:1、 总结了几十年来车桥振动分析的研究历史和主要的研究成果,阐述了车制振动对桥梁结构的危害和研究内容以及方法手段。

2、 建立了具有11自由度的车辆模型,推导了车辆的振动微分方程;建立了桥梁的空间有限元模型并推导了桥梁的振动微分方程建立了车桥耦合系统微分振动方程3、 从车辆行驶速度、路面不平整度和桥墩高度等几个方面研究了桥梁在车辆作用下的动力响应4、 对04桥规中桥梁冲击系数的数学表达式做了一些修正工作,主要引入了路面不平整度这一参数关键词:车桥耦合;高墩连续梁桥;振动;路面不平整度;冲击系数ABSTRACTWhen the vehicles travel across the bridge structures at a certain speed, the bridges will occur a certain of vibrations due to the vibrations of the vehicles’ engines and pavement roughness.The vibrations caused by the vehicle have some impact on the vehicles traveling across the bridges,so the vibrations between both of them is the mutual influence of interrelated,which is the general definition of the vehicle-bridge coupling system.Even there is not other external forces, the vibration may be occurred tempestuously. The shaking of the vehicle engines and pavement roughness can cause the vibration. When the frequency ratio of the vehicle's vibration frequency and the natural frequencies of the bridge is very close to or equal, the sympathetic vibration will occur, and bridge structures are damaged,which can cause engineering and traffic accidents.Generally speaking the two main research contents of the vehicle-bridge coupling system is:first,the impact action of vehicles on the bridge when vehicles are traveling across the bridge , which is of great significance on evaluating the working state of the bridge and service life; Second, the vibration of the bridge itself may affect the safety and comfort of vehicle. Studies show that the more poorer pavement roughness is, the more obvious vehicle dynamic response is,and the vertical displacement, acceleration response and impact coefficient is significantly larger at mid-span, therefore based on the consideration the author update the mathematical expression of impact coefficient regulated in the General Specification for Highway Bridge and Culvert Design(JTG D60-2004).This dissertation is included in the following national natural science foundation:Research on high-pier large span continuous rigid frame bridge's vibration characteristics and driving comfort level under random traffic(Foundation NO:51108045);Evaluate,response and manage system of reliability of road and bridge driving security under windy situation(Foundation NO:51178066).The main research contents of this article are showed as the following:1. The author summarized the research history and the main research results of the vehicle-bridge coupling by decades, and elaborated the damage to the bridge structure cased by vibration and the research contents and methods.2. Vehicle model with 11 degrees of freedom was established, and dynamic equilibrium equations are derived based on the principle of vehicle Darren Bell.We established a bridge spatial finite element model and derived the vibration differential equations of the bridge.The vibration differential equations of vehicle-bridge coupling system was established.3. we research on the dynamic response of vehicle under the action of the bridge on several aspects,such as the vehicle speed, pavement smoothness, pier height and so on.4.The author has updated the mathematical expression of impact coefficient regulated in the General Specification for Highway Bridge and Culvert Design(JTG D60-2004) by introducing the parameter of pavement roughness.Keyword:vehicle-bridge coupling system;continuous girder bridge with high-pier; vibration; pavement roughness; impact coefficientI目录摘要 IABSTRACT II第一章 绪论1.1课题的研究意义 11.2 车桥耦合的研究内容 21.3 影响车桥耦合的主要因素 31.4车桥耦合振动的研究方法 51.4.1车辆模型 51.4.2桥梁模型 71.4.3车桥振动数值计算方法 81.5车桥振动研究历史和现状 91.5.1古典理论 91.5.2现代理论 141.5.3铁路桥梁的车桥振动研究 151.5.4公路桥梁的车桥振动研究 161.6公路桥梁冲击系数分析 181.7本文的主要工作 20第二章 车桥系统空间耦合分析分析2.1车辆模型的建立 212.1.1选取车辆自由度 222.1.2车辆参数 232.2车辆运动方程的建立 232.2.1弹簧伸缩量计算 232.2.2车身运动微分方程的建立 242.2.3车辆运动方程的矩阵形式 292.3桥梁的运动方程 312.4车桥系统振动方程的建立 312.5车桥系统运动方程分析 322.5.1车桥系统的几何协调关系 322.5.2车桥系统力的平衡耦合关系 332.5.3路面不平整的表示方法 342.5.4车桥系统振动方程的建立 362.6 车桥系统运动方程的求解 372.7车桥耦合系统分析软件简介 392.8本章小结 39第三章 连续梁桥的车桥耦合振动分析3.1工程背景简介 403.2建立桥梁模型 403.3特征值分析结果 423.4 车桥系统振动方程 453.4.1 车辆分析参数 453.4.2 车桥系统振动方程 453.5桥梁的竖向动力响应分析结果 463.5.1车辆速度的影响 463.5.2车辆悬架刚度的影响 483.5.3不同车重的影响 513.5.4桥墩高度的影响 523.5.5路面粗糙度的影响 543.5.6 桥梁质量的影响 563.6桥梁的横向振动响应分析 583.6.1不同车速对桥梁横向振动挠度的影响 583.6.2 不同车重对桥梁横向振动挠度的影响 593.6.3 路面不平整等级对桥梁横向振动挠度的影响 603.6.4 墩高对桥梁横向。

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