THE PVDF-BASED WAVE-NUMBER DOMAIN SENSING TECHNIQUES FOR ACTIVE SOUNDRADIATION CONTROL FROM A SIMPLY SUPPORTED BEAM

This work presents a novel wave number domain sensing approach which a pplies polyvinylidene fluoride (PVDF) films for active structural acou stic control. An array of PVDF strip films is equally distributed over a beam to measure the structural response. The PVDF voltage wave numb er transform functions can then be obtained by performing the discrete wave number transform on the sensing signals. The cost function can b e defined as the sum of mean square values of the supersonic component s of the wave number transform function. The linear quadratic optimiza tion process can be applied to obtain the optimal control inputs, ther eby minimizing the cost function. This work also considers the simply supported beam with infinite rigid baffle subjected to a harmonic poin t force disturbance. The PVDF-based wave number domain sensing approac h is applied, while piezoelectric actuators are used as control inputs . In addition, the sensing method's performance is evaluated by compar ing with an accelerometer based wave number domain sensing approach. B oth continuous and discrete wave number transform approaches are prese nted as well. Analysis results demonstrate that the wave number domain sensing approach cannot only provide efficient signals that are relat ed to the structure-borne sound, but is also quite effective in contro lling sound radiation. This work advances current efforts to apply the sensing ability of intelligent material structure systems to actively control structural sound radiation. (C) 1998 Acoustical Society of Am erica.