An experimental study of a five storey steel frame using semi-active control system

An experimental study of a Five Storey Steel Frame has been conducted to investigate the performance of semi-active control system using MR (Magneto-rheological) damper. One single MR damper is installed in the first storey and supported by a steel bracing. Two benchmark earthquakes, EI Centro and Kobe, are adopted to verify the robustness of semi-active controller. Clipped modified optimal control is developed to take advantage of MR damper characteristics to produce an effective control system using the concept of on-off controller. And the performance of proposed control system is investigated and compared to the performance of no control and two passive cases: passiveoff and passive-on. The results show that the use of MR damper is effective in reducing structural responses subjected to earthquake excitations and can be implemented in real applications. This system is able to offer displacement reductions of up to 50 %.