2nd Croatian Conference on Earthquake Engineering 2CroCEE

The viscous damper produces a force proportional to the velocity by moving the fluid inside their cylinder and, causes energy dissipation due to the dynamic vibrations by converting mechanical energy into heat. Viscose dampers with their three special features as powerful passive control devices have been widely studied in recent decades. The ability to improve the seismic performance of the structures with significant energy loss, production of out-of-phase damping force relative to displacement, and the increase of the structural damping without making major changes in the stiffness characteristics of the structure are its distinguishing features in comparison with other passive control methods. In this study, the seismic performance of viscous dampers is investigated to control the vibration of three benchmark steel buildings (i.e. 3-, 9-, and 20-story buildings designed for the SAC project) under two sets of recorded near-fault ground motions possessing forward-directivity or fling-step features and compared with the building responses under a suite of far-fault accelerograms. The results indicate the superior performance of viscous dampers in low-rise buildings and under far-fault earthquakes, i.e. 59% and 53% reduction in the mean of the maximum roof displacement and velocity, respectively. However, to control the mean of the maximum roof acceleration, the best performance was attained in high-rise buildings and under far-fault earthquakes, showing a maximum of 84% reduction. In general, it can be concluded that the damper has the highest reduction in acceleration response under the far-fault records, and under the near-fault records with forward directivity has the least decrease in the velocity response.