両端から全長1/Nの位置に変位拘束部材を有する弦の自由振動

（Nが偶数，弦と変位拘束部材との間にギャップがない場合）

抄録

Elevator rope for high-rise building vibrates largely due to the resonance of the building and the elevator rope by the displacement of the building induced by strong winds and earthquakes. As building heights increase, elevator rope becomes longer. These factors cause problems of collisions and entanglement to the hoistway equipment of the elevator. Therefore, suppression of elevator rope vibration is desired. In previous paper, when elevator cage is stationary, a 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, an exact solution to the free vibration of the rope with vibration suppressors located at 1/N from both ends of the rope has been presented in the case where N is an odd number. However, in the case where N is an even number, no exact solution of the free vibration has yet been obtained. In this paper, an exact solution to the free vibration of this case (N is an even number) is presented, when center position of the rope is pulled. The rope is modeled with string. Finite difference analyses of the rope vibration with vibration suppressor are also performed. The calculated results of the finite difference analyses are in good agreement with those of the exact solution.