2020 年 86 巻 886 号 p. 19-00405
Vibration suppression devices, such as a semiactive damper, are common use for vibration reduction. In general, many of them have a controllable flexibility, damping and friction. The authors have developed variable inertia damper by using Magneto-Rheological (MR) fluid with a long by-pass pipe in previous study. In this study a new type vibration suppression device, which is having variable moment of inertia by using the MR fluid, is developed. The MR fluid is filled into the flywheel, and magnetic field is applied to the flywheel by electromagnets. The moment of inertia of the flywheel is depended on own weight and a radius of gyration. If the radius of gyration is changed because ferrite particles of the MR fluid are clustered when magnetic field is applied, the vibration suppression device can have a variable moment of inertia effect. In order to confirm the effect, a prototype vibration suppression device was manufactured, and resisting force characteristics of the device were investigated. To confirm validity of the vibration reduction, vibration tests of one degree-of-freedom system with the vibration suppression device were carried out by a shaking table. From the experimental results, the peaks of response acceleration and displacement decrease about 1/2 in case with the vibration suppression device, and also cut 5 % by the inertia effect under earthquakes. Finally, feasibility study and the effect of variable moment of inertia for vibration suppression were confirmed.
