GA-OPTIMIZED SEMI-ACTIVE FUZZY BASED CONTROLLER FOR SEISMIC VIBRATION REDUCTION OF A 3 DOF STRUCTURE WITH VELOCITY FEEDBACK

This paper aims to evaluate the effectiveness of a semi-active fuzzy logic based controller (FLC) with velocity feedback to reduce the response of a three degree-of-freedom (DOF) system representing a three floor shear building frame under seismic excitation. The proposed FLC controller uses the first and third floor velocity measurements to determine the desired control signal to command a MR damper. In this study the actuator is rigidly attached between the first floor of the structure and ground. The membership functions of the FLC were optimized using a genetic algorithm (GA) in order to obtain the best relationship between the controller inputs and output according with a predefined training data. The comparison between the uncontrolled and the controlled structural responses is used to assess the performance of the proposed semi-active FLC controller.