Abstract
The semi-active oil damper described in this paper switches is damping coefficient from maximum to minimum and dissipates twice as much energy as an ordinary passive damper. Its performance has been already verified under both dynamic loading tests with the full-scale device and the forced vibration test on the mid-rise building which was the first building with this semi-active oil damper. In order to verify the performance of this semi-active oil damper under low frequency and small vibration, forced vibration test was conducted on a high-rise building whose first natural period is over 4sec. The results showed that the damper added a lot of damping even at a very small stroke, about 0.1mm.
