Active control of vibrations of the structure equipped with magnetorheological (MR) damper using fuzzy control system and optimization with PSO algorithm.

Control systems are one of the best ways to reduce damage to structures against natural disasters such as earthquakes, which has received special attention from researchers. In this regard, the role and effectiveness of the application of semi-active control systems due to high performance in controlling structures and maintaining their stability without the need for a large energy source has been considered. What is important is to increase the efficiency of these systems with the help of modification methods and provide appropriate algorithms that can manage the behavior of these systems. Previous studies have shown that the use of dampers in construction frames is limited by their performance. In this research, the enhancement of MR damper performance in the seismic control of frame-shaped structures was studied using a modification mechanism. To this aim, a three-story benchmark shear frame structure was considered under the modification mechanism. The performance of the control system was evaluated under Electro earthquake record. In determining the seismic responses of a structure, the motion equations of a building equipped with an MR damper are studied and solved. By changing the input voltage, the MR attenuator produced the damping force to reduce the responses of the structure. The results indicated that by retrofitting the structure with an MR damper using the PSO algorithm, the displacement responses of the corner of the roof of the structure have decreased by 91.75 percent compared to the uncontrolled mode. Regarding the fact that one of the most important issues in natural systems is the issue of uncertainty and fuzziness, in this research, by using fuzzy inference and optimizing using the PSO algorithm along with MR dampers, the system was controlled and improved. Furthermore, the results were better than the similar case that used the genetic algorithm, the damping time was shorter, and the damping rate was higher. Based on this, the difference between using the PSO algorithm and genetic algorithm in reducing roof corner displacement is 69.61 percent. [ABSTRACT FROM AUTHOR]