Dynamic Vibration Absorbers for Gondola

Ropeways are commonly used for skiing and sightseeing venues and urban transportation. The swing of ropeway carriers is easily induced by wind loading, rendering them inoperable for wind speeds in excess of about 15 m/s. This problem has attracted much research attention in the past few decades. The research work has primarily focused on two methods to reduce swing that involve a dynamic vibration absorber and a gyroscope. 

From these equations, the frequency responses are obtained using a standard procedure to give 

In the case of a normal absorber as shown in Fig. 8.63, one could evaluate the efEciency by considering the mass ratio ma/mi. Clearly, in most applications the efHciency of the absorber is a critical parameter and should therefore be maximized. In the case of an absorber installed in a building, efEciency is proportional to the mass ratio and square of the displacement amplitude of the building. Therefore, the absorber must be located on a high floor. In the case of the gondola, the efficiency is given by 

This expression is referred to as the equivalent mass ratio. The equivalent mass ratio is thus proportional to the nominal mass ratio m2/mi and the square of the distance between the absorber and the center of oscillation G. This means that if the dynamic absorber is attached to the center of 

Based on the theoretical predictions and the experiments described above, in 1995 dynamic absorbers were installed on chair lifts in Japan. This is the first application of dynamic absorbers for ropeway carriers in the world. An 

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