动力吸振器对有轨电车弹性车轮的减振降噪影响分析

Effects of Dynamic Vibration Absorbers on Vibration and Noise Reduction of Tram Resilient Wheels

为了评价有轨电车弹性车轮动力吸振器的减振降噪效果,通过实验室测试方法对动力吸振器进行振动噪声测试,并结合理论和仿真来分析其降噪特性。首先,在半消声室分别测试弹性车轮在有无动力吸振器情况下的振动声辐射,测试结果表明:动力吸振器对弹性车轮轴向振动有明显的抑制作用。径向激励下,动力吸振器的降噪量为0.6d B(A),轴向激励下,动力吸振器的降噪量为2.6 d B(A)。进而,基于动力吸振原理探究动力吸振器的降噪性能,并结合测试图纸建立动力吸振器有限元模型,分析表明:动力吸振器在车轮固有频率2 066 Hz、2 245 Hz和3 837 Hz处降噪效果较好,原因是降噪频率差值在2%以内,调谐频率和理论最优频率相吻合。动力吸振器在车轮固有频率899 Hz处降噪效果较差,其降噪频率差值为6.26%,由于调谐减振频率偏离最优同调条件,导致降噪性能的恶化。

In order to evaluate the vibration and noise reduction effect of the dynamic vibration absorbers attached to tram resilient wheels, the vibration and noise of the absorbers has been measured experimentally. Combining the test results with simulation results, the noise reduction characteristics of the absorbers are analyzed. First of all, the radiation noise of the resilient wheels with and without the dynamic vibration absorbers attached is measured in a semi-anechoic room. The measured results show that the dynamic vibration absorbers have significant effects for suppressing the axial vibration of the resilient wheels. Under the radial excitation, the noise reduction effect of the absorbers can reach 0.6 d B（A）. Under the axial excitation, the noise reduction effect of the absorbers can reach 2.6 d B（A）. Then, based on the principle of dynamic vibration absorption, the noise reduction performance of the dynamic vibration absorbers is studied, and the finite element model of the dynamic vibration absorbers is established according to the design drawings. Results show that the dynamic vibration absorbers have better noise reduction effects at 2 066 Hz, 2 245 Hz and 3 837 Hz frequencies because the difference of the tuning frequency and the theoretical optimum frequency is less than 2 % and these two frequencies almost coincide each other. The dynamic vibration absorber has worse noise reduction effect at 899 Hz because the difference of the tuning frequency and the theoretical optimum frequency is 6.26 % and the tuning frequency deviates from the optimal co-homology condition, resulting in deterioration of the noise reduction performance of the absorbers.