Abstract
When an elevator rope for a high-rise building is forcibly excited by the displacements of the building induced by wind forces and/or by long-period ground motion, rope displacement becomes large even if the ground acceleration and the buildings acceleration are small. In previous paper, when elevator cage is stationary, a new practical method for reducing the rope vibration by using vibration suppressors is proposed for relaxing the restricted elevator operation. The advantage of using the vibration suppressors for reducing the rope lateral vibration is demonstrated through numerical calculation. Further, when arbitrary position of the rope is pulled, exact solution to the free vibration of the rope with vibration suppressor, which located at the center of the rope and the gap between rope and vibration suppressor is 0, has been presented. However, in the case where the position of vibration suppressor is center of the rope and the gap between rope and vibration suppressor is not 0, no exact solution to the free vibration has yet been obtained. In this paper, an exact solution to the free vibration of this case is presented. In the analysis, the rope is modeled with string. Finite difference analyses of the rope vibration with vibration suppressor are also performed to verify the validity of this exact solution. The calculated results of the finite difference analyses are in fairly good agreement with those of the exact solution.
