摘要
为探究轴重对有砟道床动力特性的影响,文章基于真实道砟颗粒轮廓,采用离散元法建立有砟道床模型。在此基础上,分析轴重对道床能量耗散、道砟颗粒运动模式以及接触力的影响。研究结果表明:加载初期道床能量出现陡增现象,随着循环荷载次数的增加,道床能量呈近似线性增长。摩擦能耗散占比约为阻尼能耗散占比的2倍。对于道砟颗粒横向位移,轴重由13t增长到40t时,砟肩下方区域横向位移影响范围从砟肩先向下部扩散,随后呈逆时针方向朝道砟坡面与砟肩外侧扩散。在轴重作用下,向外侧移动的道砟颗粒数量约为向内侧移动道砟颗粒数量的两倍,并且两者均随轴重的增加而增大。对于道砟颗粒旋转量,轴重超过25t后其影响区域逐渐由砟肩下方区域转移至轨枕下方区域。与道砟颗粒产生的转动动能相比,平动动能更大,并且两者差距随轴重增大而增大。轴重荷载主要由轨枕下方梯形区域内的道砟承担,其中轴重较小时,力链主要集中在加载区域下方。
In order to study the influence of axle load on the dynamic characteristics of ballast beds,a ballast bed model was established using the discrete element method(DEM)based on the real ballast particle profiles.Then the effects of axle load on energy dissipation,ballast particle movement patterns,and contact forces were analyzed.The results show that at the initial stage of loading,there is a sharp increase in the energy of ballast beds,which then grows almost linearly with the number of load cycles.The proportion of energy dissipated by friction is about twice that of damping energy dissipation.For the lateral displacement of ballast particles beneath the ballast shoulder,when axle load increases from 13t to 40t,its distribution area initially extends downward and subsequently propagates counterclockwise toward the ballast slope and outside of the ballast shoulder.The number of ballast particles moving outward is about twice that of those moving inward,and both of them increase with the axle load.As for the rotation of ballast particles,when the axle load exceeds 25t,its distribution area gradually shifts from the ballast shoulder to the sleepers.Compared to the rotational kinetic energy of ballast particles,translational kinetic energy is greater,and the disparity between them increases with the axle load.The axle load is primarily borne by the ballast in the trapezoidal area beneath the sleepers,where the force chains are mainly concentrated beneath the loading area in case of small axle load.
作者
徐鹏
钟熠
李婷
杨广庆
Xu Peng;Zhong Yi;Li Ting;Yang Guangqing(State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures,Shijiazhuang Tiedao University,Shijiazhuang 050043,China;Southwest Jiaotong University,Chengdu 060031,China;School of Civil Engineering,Shijiazhuang Tiedao University,Shijiazhuang 050043,China)
出处
《土木工程学报》
北大核心
2025年第7期121-128,共8页
China Civil Engineering Journal
基金
国家自然科学基金(52208358,52108331)。
关键词
有砟道床
离散元法
能量
道砟位移
轴重
ballast bed
discrete element method
energy
ballast displacement
axle load
