Abstract
When an elevator rope of a high-rise building is forcibly excited by the displacements of the building, which are induced by the wind forces and/or by long-period ground motion, the rope displacement becomes large, even if the ground and the building acceleration are small. To prevent this problem, vibration suppressors are used to change the natural frequency of the elevator rope and prevent resonance. The elevator rope is generally modeled using a string, and linear string vibration is well researched. However, the vibration of the string equipped with vibration suppressor encounters geometric nonlinearity, and hence, its characteristics have been studied under a few conditions. In this paper, to obtain the resonant frequency for the forced vibration, a finite difference analysis of the rope with one vibration suppressor is performed. Further, the resonant frequencies are compared to the natural frequencies obtained by theoretical analysis of the free vibration. The resonant frequencies are in good agreement with the natural frequencies, and the number of resonant frequencies near original natural frequency is N-1 when position of vibration suppressor is 1/N of the rope.
