高速铁路轨道不平顺与车辆动力响应的空频相干分析

Space-frequency Coherence Analysis of Track Irregularities and Vehicle Dynamic Responses for High-speed Railway Based on Wavelet Transform

轨道几何不平顺是轮轨系统产生振动及动力响应的主要原因,但轨道不平顺与车辆动力响应并非直接对应。为探究对车辆动力响应有显著影响的几何不平顺参数及其对应的波长和里程位置,利用运营线路实测的轨道检测数据,基于小波变换的时频多分辨特性,提出从空-频联合平面内分析轨道不平顺参数之间的关系,以及与车辆动力学指标的相干性。研究表明,影响车体垂向加速度的主要因素是波长16.0~64.0 m范围的高低,其次是波长64.0~189.6 m波段的水平、三角坑,而轨向、轨距等横向几何不平顺参数对其几乎没有影响。影响车体横向加速度的主要因素是波长96.0~155.0 m范围的轨向及波长128.0 m附近的水平、三角坑,轨距与车体横向加速度相关性较弱,对其影响较小。研究结果表明,通过小波时频相干函数可以同时确定对车辆动力响应有较大影响的几何不平顺波长分布和空间位置,为科学、合理地评价轨道几何状态奠定基础。

Track geometric irregularities are the main causes of vibration and dynamic responses of wheel-rail system.However,track irregularities and vehicle dynamic responses do not always correspond to each other.In order to explore the geometric irregularity parameters that have significant impacts on the vehicle dynamic response and their corresponding wavelengths and spatial positions,the correlation was proposed between track irregularity parameters and vehicle dynamics indicators from the space-frequency joint plane based the multiresolution characteristics of wavelet transform.Through wavelet coherence analysis,the alignments and longitudinal levels of the left and right rails have strong correlation within the whole detection wavelength range.The main factors causing the vertical acceleration of the car-body are the longitudinal level in the wavelength of 16.0~64.0 m and the cross level and twist in the wavelength of 64.0~189.6 m.The alignment and gauge have a relatively small impact on the vertical acceleration of the car body.The alignment in the wavelength of 96.0~155.0 m and the cross level and twist in the wavelength of 128.0 m have a strong correlation with the car-body lateral acceleration,which means that they are the main geometric factors that affect the dynamic response.The wavelength distribution and spatial position of geometric irregularities which have a great impact on vehicle dynamic responses can be determined simultaneously by wavelet time-frequency coherence function,which lays the foundation for scientific and reasonable evaluation of track geometric state.