| Budget Amount *help |
¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1998: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1997: ¥900,000 (Direct Cost: ¥900,000)
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| Research Abstract |
Complicated three-dimensional flexible structures like piping systems, cranes and tower-like structures are likely to result in intricate vibrations during an earthquake or a strong wind. In this research, a three-link am type vibration control device using giant magnetostrictive actuators was developed in order to suppress such indicate vibrations. The vibration control device is composed of four universal joints, three links and two end mounting plates. The links and the mounting plates are connected in series through universal joints, and each universal joint consists of a steel ball, a ball holder, a lever mechanism and agiant magnetostrictive actuator. The device resembles a human ami and is able to produce controllable friction forces and torques in three translational and rotational directions, respectively.
A trial vibration control device was made and the resisting force characteristics in three translational directions were measured. The seismic responses of a two degrees of fredom system and a three degrees of freedom system consisting of a mass and four coil springs and supported by the vibration control deve were investigated experimentally using a two-dimensional electrohydraulic shaking table. The experimental results were compared with the calculated ones, and the effect of vibration suppression of the device and the validity of the calculations were confirmed.
The effect of vibration suppression of the vibration control device depends on the stiffnesses of the elastic hinges used in the lever mechanisms. Accordingly, the optimum design method of the elastic hinge for getting maximum frictional force generated in each universal joint was also discussed theoretically and experimentally.
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