摘要
在高铁和地铁线路上最常见的轨道扣件是所谓的“蝶形”弹条,这种弹条在使用过程中由于钢轨波浪或车轮多边形磨耗引起的高频激励而经常出现弹条断裂的情况,弹条断裂的主要原因之一是弹跟内弧面的应力集中。对弹条断裂现场的调查发现钢轨表面有明显的周期性波浪磨耗或运营车辆车轮存在周期性车轮多边形,表明导致弹条断裂的激励力和钢轨波浪磨耗或车轮多变形有关联。根据在线测量的波浪磨耗的波长、列车运行速度以及车辆轨道耦合系统的横向p-p频率,估算出由于波浪磨耗引入的激励力频率范围是400~800 Hz。通过对弹条动态特性的实验研究和理论分析,发现弹条两个主要模态频率在500、600 Hz与周期性波浪磨耗产生的高频激励频率相接近从而导致扣件弹条疲劳断裂。提出一种简单而有效的解决方案,以使共振频率远离激发范围。优化后的弹条应力响应能够降低了80%以上,主要模态频率提高了40%,达到了避免疲劳损坏的目的。
Studies on the fatigue damage,induced by high frequency excitation from rail/wheel surface corrugation,of a common type rail fastening clip were presented.The subject clip,called“Butterfly-type spring clip”due to its shape,is widely installed in high speed rail and subway tracks.One of the main reasons for the clip failure is the broken wings due to the stress concentration at the curved inner surface of the clip heel.On-site inspections found evident rail/wheel surface corrugation at the sections where broken clips were found,indicating the excitation source causing fatigue damage was linked to the rail/wheel corrugation.Based on the measured wavelength ranges of corrugation marks and their relationship with train speeds and lateral pinned-pinned frequency of the wheel-rail coupling system,the estimated excitation frequency range related to the corrugation was 400~800 Hz.Experimental studies on the dynamic properties of the clips and in laboratory together with finite element analysis found two dominant modal frequencies of the clip near 500 Hz and 600 Hz,which resonated with corrugation-induced excitation and resulted in fatigue damage of the subject clip.A simple but effective remedial solution was proposed to shift the resonance frequencies away from the excitation range.Analysis of modified clip confirmed that the dominant resonance frequency of the peak stress response was increased over 40%for the inner surface of heel curves,and the peak stress response levels were reduced by 80%in the excitation frequency range related to rail corrugation,realizing the avoidance of fatigue damage.
作者
王安斌
高晓刚
肖俊恒
闫子权
WANG Anbin;GAO Xiaogang;XIAO Junheng;YAN Ziquan(School of Urban Railway Transportation,Shanghai University of Engineering Science,Shanghai 201620,China;Railway Engineering Research Institute,China Academy of Railway Sciences Corporation Limited,Beijing 100081,China)
出处
《铁道学报》
EI
CAS
CSCD
北大核心
2021年第9期93-99,共7页
Journal of the China Railway Society
基金
高速铁路轨道技术国家重点实验室开放基金(2017YJ093)
国家自然科学基金(U1834201)。
关键词
轮轨波浪磨耗
高频振动
轮轨激励
扣件弹条
疲劳断裂
wheel/rail corrugation
high frequency vibration
wheel/rail excitation
fastening clip
fatigue fracture
