Suppression of transverse vibration of elevator rope using dynamic damper

Abstract

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. In high-rise building, the elevator rope may resonate with natural frequency of the building, and lateral vibration becomes large; hence, effective solution to reduce the rope displacement is demanded. In this paper, a method to suppress the rope displacement by using dynamic damper is proposed. Rope lateral vibration is controlled by fluctuating rope tension using up-and-down motion of this dynamic damper. Finite difference analyses of rope vibration with dynamic damper are performed to verify the validity of this method. Experiments involving forced vibration of a rope whose length is constant are also performed. The optimal natural frequency of this dynamic damper is about 2 times of the natural frequency of the rope lateral vibration. The rope sway can be reduced to about 1/2, when the cage is stopped.