UNCERTAINTY ANALYSIS IN A ROTOR SYSTEM BY USING THE FUZZY LOGIC APPROACH
Wagner José G SILVA PINTO1; Arinan Dourado GUERRA SILVA1; Aldemir Ap CAVALINI JR1; Valder STEFFEN JR1
1 UFU (Federal University of Uberlândia)
doi:10.20906/CPS/CILAMCE2015-0340
Resumo
This paper is dedicated to the uncertainty analysis of the dynamic response of a simple supported rotor system composed by a horizontal flexible shaft, one rigid disc, and one additional ball bearing. A mathematical model of the rotor is derived from the Lagrange's equation by using the Rayleigh-Ritz method. Some simplifications are adopted in order to obtain the responses of the considered rotor system. The inherent uncertainties of the bearing are modeled through fuzzy logic technique. Triangular fuzzy numbers represents the uncertain stiffness of the rotor's bearing. Direct and heuristic optimization algorithms are used in the α-level optimization to map the fuzzy inputs. A defuzzification process is carried out to estimate the stiffness of the bearing regarding the considered uncertain interval. The analysis is confined to the time domain so that the envelopes of the rotor unbalance responses are evaluated.
Palavras-chave: rotor dynamics; simplified rotor model; fuzzy logic; defuzzification; optimization