团雾环境下车流发展仿真及车-桥耦合振动分析  

Simulation of vehicle flow development and analysis of vehicle bridge coupling vibration in mass fog environment

作　　者：刘焕举 刘宁 LIU Huanju;LIU Ning(School of Civil Engineering,Hebei University of Engineering,Handan 056038,China)

机构地区：[1]河北工程大学土木工程学院,河北邯郸056038

出　　处：《振动与冲击》2022年第6期106-114,共9页Journal of Vibration and Shock

基　　金：国家自然科学基金青年科学基金(51908178);河北省普通高等学校青年拔尖人才计划(BJ2020012)。

摘　　要：团雾桥域多状态车流并存且动态发展,引发桥梁竖向作用密度剧变及纵向作用力动态施加,为实现团雾环境下结构效应分析,团雾下仿真车流的发展和完善车-桥耦合力学关系两个关键问题需要解决。首先团雾边界立面化,抽象实际团雾为团雾匣,依据团雾中车流行进规律,连续划分团雾桥域,确定各桥段车流行进参数,建立团雾状况下车流发展模型,通过团雾边界识别确立车流模型中的变速点,编制车流仿真模块并程序衔接。其次团雾中车辆先减速再匀速最后加速的运动状态,突破了宏观车流一次恒定变速常规,需匹配车辆变速力学模型并融入车-桥耦合系统,构建团雾状况下车-桥系统响应分析平台。最后以一座典型斜拉桥为背景桥梁,计算确定桥梁响应的团雾影响因素和分析指标,进行团雾范围和位置因素对桥梁响应影响的分析。结果表明:团雾状况下梁端顺桥向和跨中竖向位移均超越等保有量状况和标准车流状况,团雾位于跨中时极值最大,桥梁响应分析时,团雾引起桥上汽车荷载分布不均衡和产生纵向力的影响需充分考虑;团雾范围不变,位置由跨中向梁端流动时,团雾对桥梁纵、竖位移响应影响逐渐降低;团雾中心定于跨中,随团雾范围向两侧扩展时,梁端顺桥向位移先增大后减小,跨中竖向位移逐渐减小并趋近于1。The coexistence and dynamic development of multi-state traffic flow in the mass fog bridge area lead to a drastic change of the vertical action density and the dynamic applying of longitudinal force.In order to analyze the structure effect in the fog environment,two key problems need to be solved,namely,the simulation of vehicle flow development under mass fog and the improvement of the vehicle bridge coupling mechanical interaction.Firstly,the fog boundary was assumed as a vertical one,and the actual mass fog was abstracted as a mass fog box.According to the popular characteristics of mass fog vehicles,the mass fog bridge area was continuously divided to deduce and determine,the calculation method for vehicle flow characteristic parameters of each bridge section,so as to form the development model of vehicle flow under the condition of mass fog.The multi-stage speed change points in the traffic flow model were determined with the method of group mass fog identification.The simulation program was compiled and connected.Then,the state of motion was set as that a vehicle decelerates first,then moves at a constant speed and finally accelerates in mass fog.This breaks through the traditional assumption of once constant speed change of macro traffic flow which needs as well to match the mechanical model of vehicle transmission and integrate into the vehicle bridge coupling system to construct the response analysis platform of the vehicle bridge system under the condition of mass fog.Finally,Taking a typical cable-stayed bridge as an example,the influential factors and analysis indexes of mass fog on the bridge responses were investigated,and the parameters of the fog range and location factors influencing the bridge responses were analysed.The results show that the displacement along the bridge and the vertical displacement of the bridge under the condition of mass fog all exceed those in the case of same ownership and standard traffic flow,the maximum value appears as the mass fog is in the middle of the span,the une

关 键 词：桥梁工程 车桥耦合 车流发展 数值仿真 团雾 

分 类 号：TU312.3[建筑科学—结构工程]