A research and development of smart building structures by magneto-rheological damper

Magneto-rheological damper (MR damper) has been expected to control the response of building structures in recent years, because of its large force capacity and variable force characteristics. Authors developed some MR dampers and conducted shaking table tests for the improvement the performance of building structures subjected by earthquake. A three-story large-scaled test frame supposing both base-isolated and normal structure was developed. As for base-isolated building, 40kN Magneto-Rheological damper was installed at base-isolation. The effectiveness of MR damper and proposed control algorithm was verified. In the other hand, a new Magneto-Rheological fluid is also developed in order to apply to the MR damper. The new MR fluid had a good property concerning the settlement of particles in dampers. The settlement was one of serious problems to be solved in handling of MR fluid in case of controlling the earthquake response of building structures. Fourth author developed a new MR fluid, which keeps the particles in the fluid adequately enough for usual use of MR damper.