Acoustic control using a self-sensing actuator

Abstract

An analytical and experimental demonstration of a self-sensing actuator that is used actively to control sound transmission/radiation through a vibrating plate is presented in this paper. Self-sensing is a novel application of piezomaterials, in which the same piece of piezomaterial is used as both a sensor and actuator. A plane acoustic wave incident on a clamped, thin circular plate was used as a noise source, and a self-sensing actuator bonded to the plate was used to control and sense vibration of the plate. The sound transmission reduction problem was approached as a structural vibration control problem that minimizes the velocity of the plate since the far-field sound pressure is related to the vibrating velocity of the structure. The results show that the first structural vibration mode is well controlled with a reduction of at least 78 percent in the displacement and velocity of the plate. This corresponds to a 13 dB reduction in the acoustic response. These results indicate that a self-sensing actuator bonded to the plate can be employed to attenuate the sound transmitted or radiated from the plate.