An intelligent base-isolation system, comprised of low damping isolation bearings and controllable fluid dampers, is studied in this paper. The damper employs a magnetorheological (MR) fluid that change its properties in the presence of a magnetic field, resulting in a damper whose characteristics may be modified in real time to adapt to changing excitations in a stable and cost-effective manner. A model of a five-story building is used to study and compare the efficacy of a passive base-isolation alone, with the addition of an active control device, and with a semi-active MR damper. A preliminary study of active H2/LQG designs shows that mostly dissipative designs exist, which may be implemented using far less power in an approximate manner with an MR damper. Simulations of the semi-active system demonstrate that the 'smart' damper can achieve most of the decrease in base displacement and peak acceleration typical of an active device.
The full paper in PDF format is here (515KB).
Other papers on magnetorheological fluid damper research can be found here.
