Semi-active Control of Building Structures using Variable Stiffness Device and Fuzzy Logic

Semi-active control devices, also called Intelligent control devices, constitute the positive aspects of both passive and active control devices. A semi-active control strategy is similar to the active controlstrategy, but this control device has been shown to be more energy-efficient than active devices. Aparticular type of semi-active control device, the Variable Stiffness Device (VSD), consists of a hydraulic cylinder with a normally closed solenoid control valve inserted in the tube connecting the two cylinder chambers. This paper emphasizes on the application of Semi-active Fuzzy Logic Controller (SFLC) of thissystem for getting the best results in the reduction of the building responses under earthquake excitations. For the numerical example, a 12-story building, located in the city of Rasht, Iran, is modeled as 3-D frame and the problem is solved in state space. The results obtained from the proposed control scheme (SFLC)are compared with those obtained from the ON-OFF control method. It is found that the SFLC is highlyeffective in reducing the responses of the example building than the ON-OFF algorithm. In this study, the optimal values of the fuzzy rule bases, membership functions, and the location of the control device are determined.

Keywords:

Semi-active Control , Variable Stiffness Device (VSD) , ON-OFF Algorithm , Fuzzy Logic Controller (FLC) ,