精准调频钢轨阻尼器设计及试验研究

Design and Experimental Study on Accurate Tuned Rail Dampers

针对钢轨阻尼器仅在较窄的频段范围内降低钢轨振动的特性,首先从理论上推导频率匹配准确性对钢轨阻尼器减振效果的影响,发现钢轨阻尼器的固有频率与钢轨振动频率匹配较好时,能够产生良好的减振效果;随后设计一种可精准调频的新型钢轨阻尼器结构,其固有频率不受夹紧力影响且对制造加工误差不敏感;最后,以5 m长钢轨1阶模态185 Hz为目标频率开展钢轨阻尼器模拟计算及试验研究,通过锤击测试和落锤测试验证该精准调频钢轨阻尼器在目标频率附近具有显著的减振效果。

Tuned Rail Damper(TRD)based on the principle of dynamic vibration absorber can only reduce rail vibration in a narrow frequency range.In this paper,the influence of frequency matching accuracy on damping effect of TRD is deduced theoretically.It is noticed that good matching between the natural frequency of the rail damper and the rail vibration frequency can yield good damping effects.Subsequently,a new type accurate frequency tunable TRD is designed.The nature frequency of the new-type TRD is independent of the clam force and the TRD is insensitive to the machining precision either.Finally,with the 185 Hz first-order modal frequency of a 5 m long rail as the target frequency,the simulation and experimental verification of the rail damper are conducted.Through the hammering test and the weight-drop test,it is identified that the accurate TRD has a significant vibration absorption effect near the target frequency.