Liquid dynamic absorbers for rolling of cable suspended carriers

自从1993年Matsuhisa证明了动力吸振器可以减小索道托架的风致摆动以来，索道托架上安装了许多吸振器。在实际使用中，在弧形轨道上由钢质移动质量组成的动力吸振器，其固有频率和阻尼系数的调谐并不容易。液体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形和U形管道动力吸振器。自然频率可以很容易地通过用水量进行调整。通过管端喷嘴直径、液体孔口直径或液体网直径以及液体的粘度，可以调节液体的阻尼系数。从理论上研究了液体动力吸振器对吊车、船舶和悬索桥的减摇效果。推导出了预测吸振器效率的公式。建立了减振器的位置和形状与减振效果的关系。利用小模型对摆式悬索桥、船舶悬索桥、悬索桥悬索桥的摆动进行了试验研究，发现吸振器具有很好的减摇效果，可以安装在真实的吊车、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.