基于冲击响应谱高速列车设备冲击环境特性分析

Analysis of shock environment characteristics of high-speed train equipment based on shock response spectrum

为准确描述列车设备受到的冲击环境,基于冲击响应谱模型将基础冲击加速度作用到一系列固有频率变化的单自由度系统上,采用系统的最大响应间接地描述冲击载荷。首先,对半正弦、梯形、前峰锯齿和后峰锯齿等经典脉冲型冲击加速度进行响应谱分析;其次,对线路实测的高速列车车体、转向架和车轴装设备的加速度振动环境,与IEC61373规范对应的半正弦冲击加速度的响应谱进行对比;最后,提出一种冲击响应谱时域合成方法,通过优化小波的幅值和相位参数使合成的冲击加速度满足目标响应谱精度要求,并反映冲击环境的方向特征。研究结果表明:脉冲型冲击加速度具有相同的响应谱特性,在低频区,加速度响应谱斜率为6 d B/Oct,速度响应谱为水平的恒速线;在高频区,正值和负值响应谱不等,在不同方向上具有不同的冲击效果;现有规范对于车体、转向架和车轴装设备存在低频过试验问题,转向架和车轴装设备同时存在高频欠试验问题,列车设备受到的均为对称冲击环境,脉冲型冲击加速度不能反映列车设备对冲击环境方向的要求;合成的冲击加速度能精确匹配目标响应谱,可以满足3 dB误差要求,更接近真实的冲击加速度瞬态波形。

To accurately describe the shock environment of train equipment,the shock acceleration was applied to a number of single-degree-of-freedom(SDOF)systems with variation of natural frequency,and the maximum response of the SDOF systems was used to describe the shock load indirectly.Firstly,the shock response spectrum(SRS)characteristics of classical impulse accelerations were analyzed,such as half-sine,trapezoidal,initial peak sawtooth and final peak sawtooth shock pulse.Secondly,the acceleration response spectrum of high-speed train body,bogie and axle mounted equipment measured on the line were compared with that of the half sine shock acceleration corresponding to IEC61373 specification.Finally,a time domain synthesis method of SRS was proposed by optimizing the amplitude and phase parameters of wavelet,which can satisfy the precision of target SRS and reflect the direction characteristics of shock environment.The results show that the acceleration shock pulses have the same response spectrum characteristics.In the low frequency range,the slope of the acceleration response spectrum is 6 dB/Oct,and the velocity response spectrum is horizontal constant speed line.In the high frequency region,the positive and negative response spectrums show that the acceleration shock pulses have obviously different shock effect in different directions.Moreover,the existing shock resistant specification for car body,bogie and axle mounted equipment have the problems of over test in the low frequency range,and bogie and axle mounted equipment have the problems of fewer test in the high frequency range.The high-speed train equipment is subjected to symmetric shock environment and the specifications can’t meet the requirements of shock direction.The synthesized shock acceleration can accurately match the target response spectrum,meet the requirement of 3 dB error,and is closer to the real acceleration shock waveform.