Abstract：The quasi-zero stiffness floating slab track system with magnetorheological damper was constructed, through introducing the horizontal spring negative stiffness mechanism and magnetorheological damper. Firstly, through the analysis of statics characteristics, the influence of structural parameters on the nonlinear stiffness and bearing capacity of the system are studied. Then, Bingham model was used to describe the magnetorheological damping force, and the nonlinear dynamic differential equation of the system was established. By using averaging method, the amplitude-frequency and phase-frequency characteristic equations were obtained, and the expression of the force transmissibility was derived. Finally, the effects of the nonlinear coefficient, vertical damping ratio, horizontal damping ratio, force excitation amplitude, coulomb damping force and viscous damping ratio on the force transmissibility are analyzed numerically. The vibration isolation performance of the quasi-zero stiffness floating slab track system with magnetorheological damper is compared with the traditional steel spring floating plate track system and the quasi-zero stiffness floating plate track system without magnetorheological damper. The results show that the proposed system with the matching parameters has low nonlinear stiffness within the displacement limit of the floating slab, and has the bearing capacity to meet the requirements of the actual working conditions. Increasing vertical damping ratio, horizontal damping ratio, coulomb damping force and viscous damping ratio can restrain the peak value of force transmissibility and improve the low frequency vibration isolation performance of the system. Increasing the nonlinear coefficient can reduce the initial vibration isolation frequency of the system and broaden the vibration isolation band. Large force excitation amplitude is beneficial to high frequency vibration isolation performance of the system. Compared with the traditional steel spring floating slab track and the quasi-zero-stiffness floating slab track without magnetorheological damper, the proposed system has better vibration isolation performance at low frequency.
2023, Vol. 44 
