| The vibration and noise problem has been a major problem in the design and operation of high speed elevators. Previous studies focus on the vibration and control of the elevator car. The vibratory energy of the moving elevator cable can be significantly higher than that of the car. The vibration of the elevator cable can reduce the cable life, increase the noise level, and affect the ride quality of the elevator system. This thesis provides a comprehensive, theoretical and experimental study of elevator cable dynamics and control.;The theoretical study concerns the free and forced lateral responses of the moving elevator cable in cable-car systems. The free vibration analysis combines and extends the recent analysis to provide the theoretical solutions for the scaled elevator model in the experimental study. A general methodology to analyze the forced lateral responses of cable-car systems with rigid and soft suspensions is developed. Excitations can arise from building sway, pulley eccentricity, and guide rail irregularity. The cable is modeled as a translating string and tensioned beams with different boundary conditions. Three discretization methods are used and shown to yield the same results. Vibration control of the elevator cable through the use of a damper is investigated. The optimal design of the damper is examined to minimize the vibratory energy. It is demonstrated that this new methodology based on the energy viewpoint can be used to optimize the design of high speed elevators.;A novel experimental method is developed next to validate the theoretical predictions for the uncontrolled and controlled, free lateral responses of a moving cable in a high rise elevator. This includes the design and fabrication of a scaled elevator, experimental setup, and development of measurement and parameter estimation techniques. Experimental results show good agreement with the theoretical predictions. |
