Document Type : Research Article
School of Civil Engineering, College of Engineering, University of Tehran, Tehran, Iran
The selection of appropriate membership functions for fuzzy control systems has always been a topic of discussion among researchers and has been generally determined by trial and error based on the experience of the control system designer. In this study, the control performance of type-1 and type-2 fuzzy systems with different membership functions in semi-active fuzzy control of three- and nine-story structures under seismic excitation of the El centro, Kern County, Northridge, and Kobe earthquakes at different maximum accelerations Will be discussed. In this study, two fuzzy systems have been used considering the type of membership function as well as the number of defined membership functions for each input. The examined membership functions are defined symmetrically and at the same intervals for comparison. The results of the control systems used for the type-1 and type-2 fuzzy algorithms are examined and compared to the uncontrolled mode by considering the triangular, Gaussian, and trapezoidal membership functions. The results obtained from the defined evaluation criteria show that in general, type-2 fuzzy systems perform better than type-1 fuzzy systems, due to the consideration of uncertainties and the use of membership functions intermittently. is Fuzzy control systems with triangular membership functions have the best performance compared to other membership functions and the Gaussian membership function has shown close control function close to triangular function. Also, when more membership functions are used to determine the degree of membership of fuzzy language values, the fuzzy system becomes less sensitive to the type of membership function used.