2000 Volume 43 Issue 3 Pages 704-711
Consideration of near-source, high velocity, long-period seismic pulses, as were recorded during the Northridge and Kobe earthquakes, has taught engineers and researchers that ground motions due to such earthquakes can be difficult to accommodate. This paper discusses a base isolation system using "smart" dampers, such as magnetorheological fluid dampers, that can adapt to, and protect against, seismic excitatiorn of different characteristics. A linear, two degree-of-freedom, lumped-mass model of a base-isolated budding is used as the testbed for this study. Linear viscous dampers are shown to have an optimal damping level for several design earthquakes to achieve minimum peak accelerations. A study of a family of controllers for the smart damper is used to find an "optimal" isolation system over the suite of ground motions considered. This "optimal" system further decreases the base drift compared to the "optimal" linear viscous damper without increasing the accelerations imparted into the superstructure. The "smart" damper is shown to be a most effective alternative for a broad class of earthquakes including near-source events.
JSME international journal. Ser. 1, Solid mechanics, strength of materials
JSME international journal. Ser. A, Mechanics and material engineering
JSME international journal. Ser. 3, Vibration, control engineering, engineering for industry
JSME international journal. Ser. C, Dynamics, control, robotics, design and manufacturing
JSME International Journal Series A Solid Mechanics and Material Engineering
JSME International Journal Series B Fluids and Thermal Engineering