Liquid dynamic absorbers for rolling of cable suspended carriers

自1993年Matsuhisa证明了可以通过动力吸振器来减小索道载体的风致摆动以来，许多吸振器已经安装在索道载体上。在实际使用中，由弧形轨道上的钢制移动质量组成的动力吸振器的固有频率和阻尼系数不易调谐。液体型动力吸振器具有固有频率和阻尼系数易于调节的优点，本文研究了由液体（水或粘性液体）组成的V形或U形管道动力吸振器。自然频率可以很容易地通过水量来调节。阻尼系数可以通过管道末端喷嘴的直径、液体中的孔板或网的直径以及液体的粘度来调节。从理论上研究了液体动力吸振器对缆车、船舶和悬索桥减摇效果。推导出了预测吸收器效率的公式。建立了减振器的位置和形状与减振效果的关系。通过对单摆、船舶和悬索桥摇摆的小模型试验研究，发现减振器能很好地减摇，并有可能安装在真实的吊篮、船舶和悬索桥上。

Since Matsuhisa has proved that the wind-induced swing of ropeway carriers could be reduced by dynamic absorbers in 1993, many absorbers have been installed in ropeway carriers. In the actual use of dynamic absorbers composed of a steel moving mass on a arc-shaped track, the tunings of natural frequency and damping coefficient are not easy. Liquid-type dynamic vibration absorbers have advantages of an easiness of tuning of the natural frequency and damping coefficient.In this study, dynamic absorbers composed of liquid (water or viscous liquid) in V-shaped or U-shaped pipes were investigated. The natural frequency can be easily adjusted by the amount of water. The damping coefficient can be adjusted by a diameter of nozzles at the terminals of pipe, an orifice or a net in liquid and the viscosity of liquid. The reduction of rolling of gondola lifts, ships and cable suspended bridge by the liquid dynamic absorbers were investigated theoretically. The formula to predict the effectiveness of the absorber was derived. The relationship between the effectiveness and the location and shape of the absorber was founded. The experimental investigations on the swing of pendulum, ship and cable suspended bridge were carried out by means of small models and it was found that the absorbers could reduce the rolling very well and it would be possible to install to the real gondolas, ships and cable suspended bridge.