Coupled Vibration Mechanism between Vertical and Horizontal Direction against Elevator Rope

Abstract

The elevator car is suspended by ropes to move vertically along the elevator shaft. When the car stops at a specific floor in the building, the car might receive a large rope sway due to the enforced motion of the building during a strong wind or a big earthquake. In general, the rope sway motion doesn’tshow a linear vibration characteristic, but the resonance peak shows softening stiffness or hardening stiffness. In this paper, simplified equations of rope motion are derived against the horizontaland vertical direction. Each equationis expressed as 1-DOF modeland the both vibration modes are coupled with each other. It is found that the coupled vibration induces the nonlinear vibration behavior.