Seismic Assessment of Controlled Optimum Benchmark Steel Structure Using Magnetorheological Damper

Magnetorheological (MR) fluid dampers are semi-active control devices that have developed widespread application in recent years to mitigate the dynamic vibrations of structures subjected to earthquakes. This study uses MR dampers to reduce the responses of a three-story benchmark steel building under four benchmark earthquake excitations. To decrease the time, cost, and computational effort, an optimized linear shear-type model of the three-story benchmark steel building is estimated using a Genetic Algorithm, demonstrating acceptable accuracy compared to its finite element model in frequency and time-history analysis. A modified Bouc-Wen model describes the dynamics of the MR damper actuator, and the damper's saturation is also considered. The damper's performance in reducing structural responses under earthquakes is evaluated under passive-off, passive-on, and fuzzy logic control algorithm strategies. The fuzzy logic controller determines the input voltage applied to the damper, which regulates the damper's control force to be effectively applied to the building. The reduction in displacement, absolute acceleration of the roof, and inter-story drifts of the building under benchmark earthquakes are investigated using the MR damper under the specified control strategies. The results confirm the effectiveness of the MR damper in mitigating the structural responses under seismic excitations.

Keywords:

Benchmark Steel Structure , Optimized Linear Shear-Type Model , Dynamic Analysis , Magnetorheological Fluid Damper , Fuzzy Logic Controller