现场调研发现,我国高铁线路运营期间扣件系统已出现多种形式伤损,因此,有必要探究高速无砟轨道扣件系统在荷载作用下的力学特性.现以我国现有的WJ-8型扣件为研究对象,建立了荷载-扣件系统三维有限元计算模型,分析了列车垂向荷载及横向力作用下扣件系统各部分结构的力学行为,并进一步对扣件系统中的弹条进行模态分析和频率分析,得到以下结论:①列车静荷载和横向力分别作用下,扣件系统中的弹条、螺栓和铁垫板受力未达到强度极限,均处于安全状态.②不同工况下弹条的基频均高于300 Hz,属于高频振动.因此,高速铁路轨道随着运营速度及轨道不平顺的变化,扣件系统的振动频率也不相同.列车通过时易引起轨道结构的高频强迫振动,若其频率与弹条固有频率相近,将成为弹条断裂破坏的主要原因.③为避免弹条因共振而发生断裂,需控制钢轨的波磨长度.运营速度为350 km/h时,波磨的波长不应小于320 mm;运营速度为300 km/h时,波磨的波长不应小于270 mm;运营速度为250 km/h时,波磨的波长不应小于230 mm.
Analysis of Force Characteristics of WJ-8 Type Fastening System
The on-site investigation found that the fastening system of China's high-speed railway lines has suffered various forms of damage during operation,Therefore,it is necessary to explore the mechanical characteristics of the fastening system of high-speed ballastless track under load.This article takes the exist-ing WJ-8 fasteners in China as the research object,establishes a three-dimensional finite element calculation model of load-fastener system,analyzes the mechanical behavior of each part of the fastening system under vertical and lateral forces of trains,and further carries out modal analysis on the elastic bars in the fastening system,Draw the following conclusions:① Under the action of static load and lateral force of trains,the e-lastic bars,bolts and iron pads in the fastening system are not stressed to the limit of strength,all in a safe state.(2)Under different working conditions,the fundamental frequency of elastic bars is higher than 300 Hz,which belongs to high-frequency vibration.Therefore,the vibration frequency of the fastening system varies with the changes in operation speed and track roughness of high-speed railway tracks.When the train passes through,it easily causes high-frequency forced vibration of the track structure.If its frequency is close to the inherent frequency of the fastener,it will become the main cause of fastener breakage.(3)To avoid reso-nance-induced fastener breakage,it is necessary to control the length of rail corrugation.When the operation speed is 350 km/h,the wavelength of corrugation should not be less than 320 mm;when the operation speed is 300 km/h,the wavelength of corrugation should not be less than 270 mm;when the operation speed is 250 km/h,the wavelength of corrugation should not be less than 230 mm.
万方数据
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