Controle ativo de ruído empregando placas retangulares com atuadores Piezoelétricos distribuídos

The present work proposes a comprehensive study regarding the use of rectangular thin plates with bonded piezoelectric patches as active noise control sources. With this aint it is developed an analytical model for the vibratory behavior of thin, uniform rectangular plates based on Kirchhoff theory. Also, the formulatlon accounting for the interaction between plates and piezoelectric actuators attached to their surface is developed. Considering as the primary source a harmonic plane oblique incident wave, it is developed a model for the vibration motion of simply supported plates exeited by sound sources. Then a study is carried out, based on Rayieigbs integral, which provides a model for the sound radiated in the far field from vibrating rectangular plates. A non adaptive optimal control system of feed/owardiype is used to obtain the optimal input voltage for the activation of piezoelectric actuators so that the acoustic power radiated in far field is minimized. It is still proposed an optimization procedure for to choice of the best posítion of the piezoelectric actuators using Genetic Algorithms. Based on the theoretical developments, a number of Computer simulations are carried out aiming at evaluating the main features of the theory studied In these simulations, it Is evaluated the influence of different parameters, such as the number, size and posítion of the actuators on the effectiveness of the control system.