ACTIVE CONTROL OF STRUCTURALLY RADIATED SOUND FROM PLATES

Active control of sound radiation from a clamped rectangular plate by piezoelectric moments is investigated both analytically and experiment ally, A new theoretical derivation for the dynamic response of a plate excited by steady-state harmonic point forces. couples, and piezomome nts is presented. Four point moments, simulating a piezoceramic patch bonded directly on the surface of the plate, are used to achieve the c ontrol, Control gain is obtained by minimizing the sound radiation pow er. The sound radiation measurement is conducted in a reverberation ro om equipped with an anechoic chamber, The results indicate that this r esearch not only provides an accurate and efficient approach to theore tically predict the response of a clamped rectangular plate subjected to piezomoment excitation but also achieves effective global attenuati on of sound radiation power. The highest reduction of the total power radiated from the plate was approximately 24 dB. (C) 1997 Acoustical S ociety of America.