Study on Viscous-Friction Hybrid Damper Installed in Industrial Plants

Abstract

Every year, many earthquakes happen in Japan. Many high rise structures which are in a long distance from the hypocenter of the earthquake resonate with the long period ground motion. In industrial plants, there are structures which have a long natural period such as boiler system, and there is a risk of resonating by long period ground motion. Recently, many industrial plants require countermeasure for long period ground motion. Various viscous dampers have been developed and applied to actual structures to suppress vibration response. However, the vibration control performance decreases with the long duration time of earthquake because of a temperature rise of the viscous material. Therefore, there is concern that these viscous dampers can not suppress vibration response in case of long period ground motion. In order to solve this problem, a viscous-friction damper in series is proposed in this study. Then, in this hybrid damper, the friction damper can absorb vibration energy as well in case of the long period ground motion. In this paper, seismic response analysis is conducted to confirm performance of hybrid damper. We propose using genetic algorithm to select parameters of the hybrid damper.