地铁钢轨短波长波磨形成原因分析

国内某地铁线路运营后曲线轨道出现了短波长钢轨波磨现象，通过力锤敲击法对不同扣件轨道动态特性进行了测试。利用ABAQUS建立了轮轨三维实体有限元模型，分析了轮轨耦合模态特性以及白噪声激励时轨道频响特性。结合试验和仿真结果，分析了轮轨结构动态特性与短波长钢轨波磨之间的相关性。研究结果表明：普通扣件和减振扣件轨道钢轨波磨主波长分别为30~63 mm和40~50 mm；白噪声激励下，两种轨道分别在450~920 Hz和570~720 Hz范围内的敏感共振频率与列车通过钢轨波磨频率(454~954 Hz和572~715 Hz)相吻合；线路轨道短波长波磨的产生主要与轨道结构高频固有特性相关，轨道短波长波磨通过频率与轮轨耦合模态频率相近，其模态振型表现为轮对弯曲扭转的同时，伴随钢轨相对轨道板的垂向弯曲振动，轮轨耦合高频模态特征加剧短波长波磨的发展。

Cause Analysis of Metro Short-Wavelength Rail Corrugation Based on Dynamic Characteristics of Wheel-Rail Structure

The phenomenon of short-wavelength rail corrugation occurs on the curved track after the operation of a metro line in China. The dynamic characteristics of track with different fasteners were tested by hammer stroke. The three-dimensional solid finite element model of wheel-rail is established by ABAQUS, and the wheel-rail coupled modal characteristics and the track frequency response characteristics under white noise excitation are analyzed. Based on the experimental and simulation results, the correlation between the dynamic characteristics of wheel-rail structure and the short-wavelength rail corrugation is analyzed. The results show that the main wavelengths of ordinary rail fasteners and vibration-damping fastener rails are 30~63 mm and 40~50 mm. Under the white noise excitation, the sensitive resonant frequencies of the two tracks in the range of 450~920 Hz and 570~720 Hz are consistent with the train passing the rail corrugation frequency (454~954 Hz and 572~715 Hz). The generation of short-wavelength corrugation of track is mainly related to the high-frequency inherent characteristics of the track structure. The short-wavelength corrugation passing frequency of tracks is similar to the wheel-rail coupling mode frequency. The mode shape is represented by the bending and torsion of the wheelset, accompanied by the vertical bending vibration of the rail relative to the track plate. The high-frequency modal characteristics of wheel-rail coupling will aggravate the development of short-wavelength corrugation.