Abstract
The structures with long periodic natural period such as high-rise building has been applied a response control device such as Tuned Mass Damper (TMD) with passive, semi-active and active type to reduce a wind induced vibration. The additional mass type damper is basically constructed from a moving mass, spring element for tuning natural period and damping element. In general, although there is a lot of type using a guide rail to support a dead load of mass, the static friction force is the most important design problem in a starting acceleration for long periodic TMD since the friction coefficient often becomes about 5/1000. For example, if the moving mass is designed to be 10 ton with 5/1000 friction coefficient, the inertia force has to be over 500 N to start the moving mass on a guide rail. Therefore, the starting acceleration of TMD depends on a friction coefficient of guide rail to support the movable mass. This study has been examined about a low friction type TMD with under 0.01m/s2 starting acceleration using an air floating system. The technique of floating system has applied to a flow dynamic conveyer to convey coal, gypsum, ash in iron places. Moreover, the floating system for a base-isolation has been already applied to some structures. Sakamoto and Sanpei et.al. developed the floating system for a detached house to lift up in seismic event over a setting acceleration. Moreover, Fujita et.al. investigated a base isolation system for light wait mechanical structure such as a server rack using an emergency earthquake prediction warning. This paper describes the system concept, the loading test to confirm a friction characteristic of proposed system as a basic performance and shaking table test to examine an actual performance of floating speed against some acceleration trigger as a first step of the research and development.
