Active control of sound radiation from rectangular plates using multiple piezoelectric actuators

Active control of sound radiation from a vibrating plate excited by a harmonic line moment is analytically investigated. This model of simply supported rectangular plate with a line moment excitation is used to simulate the vibration of a ship hull or aircraft fuselage from the Butter of ship deck or aircraft wing, respectively. The control is achieved using various configurations of piezoelectric actuators, and the strategy of radiated power minimization is used to obtain the optimal control input voltage. The efficiency of the active control is dependent on the location of the line moment and the actuators, and the attenuation of radiated sound power is related to two physical mechanisms that are modal suppression and modal restructuring. The numerical result shows that significant attenuation of radiated sound power for volumetric modes (odd, 1) in the low frequency range can be achieved with one control actuator located at the center of plate. Irrespective of whether the excitation is on or off resonance, more actuators result in higher attenuation of radiated sound power. (C) 1998 Elsevier Science B,V. All rights reserved.