高速动车组时频域响应特征及振动传递特性研究

Time and Frequency Domain Response and Vibration Transfer Characteristics of High-speed EMU

随着运行速度的提高,车辆对轮轨激励的敏感性有所增强,激扰频率范围也进一步加宽,深入研究高速列车振动特性及传递规律具有重要意义。在车辆各主要部件上布置加速度传感器,于武广客运专线上测试并获取了高速动车组轴箱、车体、构架承载部位以及齿轮箱和制动吊座等部件的垂向和横向振动加速度时间历程。对照列车运行速度,分析一、二系连接处各部件振动加速度峰值、均方根等时域特征,给出测试里程内系统振动频次和幅值之间的对应关系。利用短时傅里叶变换方法,获得系统各部件功率谱主频与运用速度之间的关系,并给出典型冲击工况下时频谱的特点。建立不同响应位置间的幅频传递函数,获得匀速、牵引加速、制动减速等不同典型工况下各部件间的频域传递特性。本文的研究工作对认识和获得动车组车辆系统振动特性具有较为重要的工程意义。

With the improvement of running speed,not only the sensitivity of the vehicle to the wheel-rail excitation improves,but also the vibration frequency domain of the vehicle system dynamics increases.Therefore,it is important to investigate the vibration characteristics and the dynamics frequency transfer of the high-speed EMU system.Accelerometers were assembled on the main parts of the vehicle to test the vibration of the vehicle system.Based on a field test results measured on Wuhan-Guangzhou high-speed railway,the vibration accelerations of wheelset boxes,car bodies,bearing parts of bogie frames,gearbox and braking crane of the EMU in vertical and lateral directions were obtained.According to the operation speed chart,the time domaindata,such as vibration acceleration peak value and RMS of the time history in the position of the primary and secondary suspension joints were compared to present the corresponding relationship between the amplitude level and the vibration frequency.The short-time Fourier transform ( STFT) method was introduced to investigate the relationship between the main vibration frequency of the power spectrum of each component of the system and the change of speed and to present the time-frequency characteristics of wheelset under typical excitation conditions.The amplitude frequency transfer functions between different response positions were then applied to survey the transfer characteristics of the key component of EMU under the working conditions including high-speed,traction acceleration,and braking deceleration.This research work aims to obtain the actual vibration characteristics of high-speed EMU and is important for engineering applications.