Vibration reduction of a high-speed train floor using multiple dynamic vibration absorbers

Abstract

Due to local resonances, high vibration levels occur frequently in high-speed train floor, which impact on the ride comfort negatively. A method to control excessive local vibration with multiple dynamic vibration absorbers (DVAs) is presented. Firstly, possible causes of the high vibration levels are investigated with operational and modal tests. Then a model of the vehicle body with multiple DVAs is established based on the modal superposition method. It is found that a strong peak at the low frequency is dominated by a single mode, which can be attenuated with under-frame equipment as a single DVA. In the frequency region between 30 and 35 Hz several local modes contribute, and are controlled with multiple DVAs. Methods are studied to determine the optimal parameters for these DVAs, including location, natural frequency and mass. For a single DVA conventional fixed-point theory is used, whereas for multiple absorbers an optimization method is proposed. Finally, the effect of the optimization is verified in a full vehicle model with frequency responses analysis. The results indicate that the proposed method can reduce the vibration of targeted modes and improve the ride quality considerably in terms of the vertical motion.