Vibration analysis of elevator rope with vibration suppressors (Identification of flexural rigidity, viscous damping and structural damping)

Abstract

When an elevator rope for a high-rise building is forcibly excited by the displacement of the building induced by wind force and/or by long-period ground motion, rope displacement becomes large even if the ground acceleration and the building acceleration is small. Vibration suppressor is used to reduce the rope vibration. The elevator rope is generally modeled using a string with viscous damping. However, the flexural rigidity and the damping property of the rope are not clear yet. In this paper, we proposed a beam model with viscous damping and structural damping. And we also proposed an estimation method of 3 parameters (equivalent flexural rigidity, viscous damping ratio, structural damping ratio). Experiments of forced vibration with/without vibration suppressor and finite difference analyses of rope vibration were performed. It is clear that the identified parameters obtained by the limited conditions of vibration suppressor are applicable to other conditions.

Keywords

• rope sway
• vibration suppressor
• forced vibration
• flexural rigidity
• viscous damping
• structural damping