车辆激励的悬挂式人非系统振动响应及舒适性

Vibration Response and Comfort of Suspended Pedestrian and Non-motor System with Vehicle Excitation

为探究公路桥梁悬挂式人非系统的车致振动响应规律及其振动舒适性,首先采用ANSYS软件建立公路桥梁上层车行道和下层人非系统的有限元模型。然后,综合考虑过桥车辆车型、车道、车速、车重、车辆间距和桥面不平顺的随机性特征,采用蒙特卡罗随机抽样法生成随机车流荷载,并对过桥车流荷载进行简化。最后,基于车-桥耦合振动理论,求解随机车流荷载作用的悬挂式人非系统振动响应,分析人非系统的行人过桥舒适性。实际工程的研究结果表明:人非系统的竖向振动响应最大,其次是纵向振动响应,而横向振动响应最小;密集车流荷载作用的人非系统振动响应大于一般车流荷载作用效应,人非系统的竖向加速度响应均方根值在边跨跨中、次边跨跨中、中跨跨中和桥墩位置都出现了峰值,其中中跨跨中位置的峰值最大;上层车行道桥面路况对下层人非系统的振动响应影响较大,桥面路况越差,振动响应就越剧烈,易导致过桥行人的不适;人非系统跨中竖向加速度响应峰值小于EN03中等舒适度限值1 m·s―2,舒适性评价等级为中等;跨中竖向加速度响应峰值达到EN03中等舒适性限值0.5 m/s2的概率大于桥跨结构其他位置的竖向振动响应峰值;行人在中跨跨中位置的振动舒适性差于桥跨其他位置的舒适性,跨中位置最易引起过桥行人的不适。

To explore the vehicle-induced vibration response rule and vibration comfort of suspended pedestrian and non-motor system on highway bridges,first,ANSYS software was used to establish finite element models of upper lane and lower pedestrian and non-motor system of highway bridge.Then,take into account the random characteristics of vehicle type,lane,speed,vehicle weight,vehicle spacing,and road surface roughness of the vehicles crossing bridge.Monte Carlo random sampling method was used to generate the random traffic loads;and the traffic loads on bridge were simplified.Finally,based on the vehicle-bridge coupling vibration theory,the vibration response of suspended pedestrian and non-motor system under random traffic loads was solved;and the pedestrian crossing comfort was analyzed.The result indicates that the vertical vibration response of pedestrian and non-motor system is the most significant,followed by the longitudinal vibration response,and the transverse vibration response is the least.The vibration response with dense traffic flow is greater than that with general traffic flow.At the mid-span of side-span,the mid-span of secondary side-span,the mid-span,and the position of bridge pier,there are root mean square peak values of vertical acceleration response;and the peak value at mid-span is the highest.The road conditions of upper carriageway have significant influences on the vibration response of lower pedestrian and non-motor system.The worse the road conditions of bridge deck,the more severe the vibration response will be,which can easily lead to discomfort for pedestrians crossing the bridge.The peak vertical acceleration response of pedestrian and non-motor system is less than the EN03 moderate comfort limit of 1 m/s 2 in mid span;and the comfort evaluation level is moderate.The probability of peak vertical acceleration response at mid-span reaches the EN03 moderate comfort limit of 0.5 m/s 2.It is greater than the peak vertical vibration response at other positions of bridge.The vibration comfort of pedestrian in mid-span position is worse than that in other positions of bridge.The mid span position is most likely to cause discomfort for pedestrian crossing the bridge.