关键词: 振动传递路径；频谱分析；模态测试；动力吸振器；频响函数；MPV

Abstract: In this paper, aiming at the problem of excessive vibration of the floor when the floor is accelerated to 3 560 r/min during the development of an MPV model, the vibration transmission path is analyzed and the vibration data of the floor and the components of the transmission path are collected. The frequency spectrum analysis confirms that the vibration source is the second-order excitation of the engine vibration, the transmission path is the right drive shaft subsystem of the transmission system. The modal test and analysis of the right drive shaft system were further carried out, and it was confirmed that the vibration frequency was the second-order modal frequency of the drive shaft system that had implemented the single-stage dynamic vibration absorber. Under the condition that the structure of the floor and drive shaft components cannot be changed, an improvement plan for the two-stage dynamic vibration absorber is proposed, and the mathematical theoretical models of the single-stage and two-stage dynamic vibration absorber are compared and analyzed. The simulation calculation of the frequency response function of the system before and after optimization predicts the effectiveness of the optimization scheme. Finally, the prototype was trial-produced and the vehicle in question was carried for comparative testing. The results showed that the floor vibration problem was significantly improved and the accuracy of the simulation results was confirmed.

Key words: Vibration transmission path; Spectrum analysis; Modal testing; Dynamic vibration absorber; Frequency response function; MPV