Development of multi-band tuned rail damper for rail vibration control

Abstract

The intense interaction force between the wheel-rail causes the vibration of wheel and rail, and generates rolling noise. Increasing the rail damper is an effective way to suppress rail vibration. In this paper, a shear-type multi-band tuned rail damper (MTRD) consist of internal mass bars and external resilient layer to reduce rail vibration is proposed. Mass bars are wrapped inside resilient layer and placed along the length of rail. Resilient layer between two adjacent mass bars can enforce them perform shearing motion corresponding to the layer along the main vibration direction of rail. Different oscillation frequencies corresponding to different mass bars can be tuned by adjusting the structure of MTRD. It achieves an increase in the operating frequency band and a widening of the operating frequency range of MTRD. The influence of parameters of MTRD on its performance is investigated by the finite element method (FEM). One of three designed MTRD models is selected for prototype production after comparative analysis. Laboratory measurements are conducted on a rail specimen and 12 m track platform. Results show the main operating frequency band of designed MTRD is in the range of 200 Hz–800 Hz, achieves the goal of the desired frequency band. Frequency response function tests of rail on 12 m platform show the MTRD could suppress rail vibration in the range of 100–2000 Hz. To estimate the practical reduction effects of MTRD on vibration, a small radius curve of metro line is selected for field measurements. The measured track decay rate (DR) shows MTRD could increase DR at frequencies above 80 Hz with a max increment of 5 dB/m and 9.3 dB/m in vertical and lateral direction respectively. Reduction of rail vibration and rolling noise when trains pass is also measured. The overall vibration level of rail achieves a max reduction of 10.9 dB and 6.3 dB in vertical and lateral directions respectively. The overall sound pressure level is reduced by 5.9 dB(A) at the speed of 60 km/h.