Development of tuned particle impact damper for reduction of transient railway vibrations

Herein, a tuned particle impact damper to reduce rail rolling noise is proposed, and its vibration reduction capability is investigated experimentally. The proposed damper was designed for easy attachment to a rail and possessed the combined characteristics of a tuned dynamic absorber and an impact damper. The vibration behaviour of the damper-attached rail was investigated using an actual UIC60 rail specimen. The measured vibration reduction performance was verified by simulation of the collision behaviours. The proposed damper exhibited excellent vibration reduction capability at a specific frequency band with additional damping in the broadband frequency range owing to partially inelastic particle impacts. A modal analysis of the tuned particle impact damper illustrated the mechanism of vibration reduction via the modal response of the proposed damper on the rail specimen. The interaction of the rail transverse vibration with the attached damper was analysed. The vibration reduction performances were investigated based on the damping coefficient predicted from both the least-squares and Prony's methods. The damping capability was identified to investigate the effects of excitation force, coefficient of restitution, mass ratio, clearance, and clamping force. Based on applying impact damping on railway tracks, the proposed tuned particle impact damper showed excellent damping capability in reducing transient vibrations, which is essential for minimising rolling noise from passing trains.