基于概率密度演化理论的尼尔森体系拱桥吊杆应力冲击系数研究  

Study on stress impact factor of suspenders of Nielsen system arch bridge based on probability density evolution method

作　　者：姜金凤 JIANG Jinfeng(School of Civil Engineering,Beijing Jiaotong University,Beijing 100044,China;Shandong Railway Investment Holding Group Co.,Ltd.,Jinan 250000,China)

机构地区：[1]北京交通大学土木建筑工程学院,北京100044 [2]山东铁路投资控股集团,山东济南250000

出　　处：《铁道科学与工程学报》2021年第9期2350-2357,共8页Journal of Railway Science and Engineering

基　　金：山东省交通运输科技计划资助项目(2020B78)。

摘　　要：基于概率密度演化理论研究列车动力荷载作用下尼尔森体系拱桥吊杆的应力冲击系数问题。提出基于概率密度演化理论和列车—轨道—桥梁耦合动力学的吊杆随机动应力分析方法。利用数论选点法得到代表性轨道不平顺随机激励样本,基于等效Hertz线性轮轨接触关系建立的列车—轨道—桥梁耦合系统动力学模型。以济青高铁线路某尼尔森体系提篮式拱桥为研究对象,基于概率密度演化方法分析车速和轨道不平顺等级对吊杆动应力均值、标准差和概率密度结果等随机振动特征的影响规律。研究结果表明:尼尔森体系拱桥吊杆动应力标准差和应力冲击系数受轨道随机不平顺激励影响显著,并随着轨道不平顺程度的减小而减小;列车处于桥梁跨中时,概率密度分布范围最宽,峰值最小;吊杆动应力均值受车速影响较小,各车速条件下的动应力标准差和应力冲击系数分布规律不一致;边吊杆处动应力均值最小,动应力标准差和应力冲击系数最大,铁路运营期应保证线路的高平顺性要求。Based on the probability density evolution method,the stress impact factor of the suspender of the Nelson system arch bridge under train dynamic load was studied.According to the vehicle-track-bridge coupling dynamics,a method for analyzing the random dynamic stress is proposed.Employing the equivalent Hertz linear wheel-rail contact relationship,the random vibration calculation model of the train-track-bridge coupling system with probability density evolution method was established.Taking a basket-type arched bridge in the Nielsen system on the Jinan-Qingdao high-speed railway as the research object,the influence laws of the train speed and grade of track irregularity on the mean,standard deviation and probability density evolution distribution of the dynamic stress of the suspenders were analyzed.The results show that the standard deviation of the dynamic stress and the stress impact factor of the suspenders of the arch bridge in the Nielsen system are significantly affected by the track random irregularity excitation,and decrease with the increase of the track irregularity level.When the train is in the middle of the bridge span,the distribution range of probability density is widest and the peak value is minimum.The mean value of the dynamic stress of the derrick is less affected by the speed of the vehicle,and the distribution law of the standard deviation of the dynamic stress and the stress impact factor under different speed conditions is not consistent.The mean value of dynamic stress and the standard deviation of dynamic stress and the stress impact factor at the side suspender are the smallest.The smoothness of the line should be paid attention to during the railway operation period.

关 键 词：概率密度演化理论 吊杆应力 随机振动 尼尔森体系 列车—轨道—桥梁耦合系统 

分 类 号：U24[交通运输工程—道路与铁道工程]