考虑车轮滚动轨迹的桥头跳车动力荷载计算方法及影响因素分析  

A NUMERICAL METHOD FOR ANALYZING THE DYNAMIC LOAD IN BRIDGE-HEAD BUMPING CONSIDERING THE ROLLING TRACE OF WHEEL AND THE ANALYSIS OF INFLUENCING FACTORS

作　　者：丁勇[1] 谢旭[2] 黄剑源[1] 

机构地区：[1]宁波大学土木工程系,宁波315211 [2]浙江大学土木工程系,杭州310027

出　　处：《工程力学》2013年第2期135-142,149,共9页Engineering Mechanics

基　　金：浙江省自然科学基金项目(Y1110548);宁波市自然科学基金项目(2009A610157);宁波市交通科技项目(200912)

摘　　要：为分析车辆桥头跳车时的动力荷载,提出了更符合实际形状的圆盘车轮模型,以考虑车轮经过桥头错台时的滚动轨迹,结合基于有限元的车辆整体模型和相应的动力学方法,实现了车辆上、下桥头错台时的竖向、顺桥向动力荷载的定量分析。算例表明,考虑车轮滚动轨迹后,动力荷载计算值比以往平缓得多;跳车动力荷载的大小与车辆的行驶速度、车轮的悬挂方式、桥头错台的高度等因素有关,其表现为:1)车辆的最大动力荷载与桥头错台高度成正比;2)对于独立悬挂的车轮,车速越大,最大动力荷载越大;对于非独立悬挂的车轮,最大动力荷载随着车速的增大呈现波动的形态;3)上桥时的最大荷载位于错台上,下桥时前、中轮的最大荷载离桥头错台较远,后轮则较近;4)桥头错台跳车造成的轮载冲击系数可能超过我国桥梁规范设计值,需要引起重视。For analyzing the dynamic load of vehicle in bridge-head bumping, a disk model is presented according to the actual shape of the wheel, and the rolling trace during the wheel passing through the staggered platform at bridge head is considered. By means of finite element modelling of the vehicle and the corresponding equilibrium equations, the vertical and horizontal dynamic loads during the vehicle passing the bridge head are analyzed quantitatively. Numerical examples show that the dynamic load of the vehicle is reduced when the rolling trace of the wheel is considered, and it is related to the moving speed, the suspension of the vehicle and the height difference of the staggered platform; for example, 1） The maximum dynamic load is proportional to the height difference of the staggered platform; 2） For the wheel independently suspended, the maximum dynamic load is proportional to the moving speed of the vehicle, whereas for the wheel dependently suspended, it fluctuates when the speed increases; 3） When the vehicle gets on the bridge, the maximum load of all the wheels is applied just on the staggered platform, front and the middle wheels is applied far whereas when the vehicle gets off the away from the staggered platform, but bridge, the maximum load of the that of the rear wheels is adjacent;4） It should be noted that the impact factor when the vehicle passes through the staggered platform at the bridge-head may be higher than that provided by the design codes of bridges.

关 键 词：桥头跳车 动力荷载 滚动轨迹 动力响应分析 冲击系数 

分 类 号：U441[建筑科学—桥梁与隧道工程]