高速列车齿轮箱箱体在位模态识别

Modal Identification of Gearbox Housing of High Speed Train under Assembly Condition

通过台架试验识别出高速列车齿轮箱装配状态下箱体的模态参数。试验中齿轮箱装配于实际的轮对系统并且模拟齿轮箱在转向架构架上的实际约束。采用多频带平稳随机激励,运用Poly MAX方法完成齿轮箱箱体前六阶模态参数(包括模态频率、阻尼比、振型)的识别,对比试验结果与仿真计算,两者相一致,表明参数识别可靠。对于模态参数识别过程中出现的虚假模态,通过在不同激励点的锤击试验获得轴、齿轮箱、轴箱等部件的响应,分析轴-齿轮箱、轴箱-齿轮箱、轴-轴箱等子系统之间的传递函数,确定虚假模态主要振动来源并探究车轴、轴箱等零部件对台架试验中齿轮箱箱体振动响应的影响。采用连续小波变换和奇异值分解相结合的方法弱化能量值较低的虚假模态,进一步提高箱体在位模态参数识别的准确性。

The modal parameters of gearbox housing of high speed train under assembly condition are identified by a specially designed test rig. The gearbox is assembled in a wheelset system and its actual constraints in the bogie frame are considered in the test. By using multi-band stationary random excitation, the recognition of the first six-order modal parameters of the gearbox housing including modal frequency, damping ratio, vibration mode is completed with Poly MAX method. The identification results agree well with the simulation, indicating that the parameter identification is reliable. For the false mode appearing in the parameter recognition process, the responses of the shaft, gearbox, axlebox and other components are obtained by selecting different excitation points through the hammer test. The main vibration source of the false mode is determined by analyzing the transfer function of the subsystems such as axle-gearbox, axle box-gearbox and axle-axle box. The influence of axle and axle box on the vibration of gearbox housing in the test rig is explored. The combination of continuous wavelet transform and singular value decomposition is used to weaken the false modal with low energy value to further improve the accuracy of the in-situ modal parameter recognition of gearbox housing.