An experimental study of the use of PVDF piezoelectric sensors in active structural acoustic approaches

Abstract

An experimental investigation was performed to determine the feasibility of implementing polyvinylidene fluoride (PVDF) piezoelectric distributed sensors on the surface of a structure as error sensors in an adaptive lms control approach to minimize acoustic radiation. A simply supported rectangular plate was chosen as the test structure and was excited by a point‐force steady‐state harmonic disturbance. Structural inputs achieved by three piezoceramic actuators bonded to the surface of the panel. Two narrow strip PVDF sensors were positioned on the plate such that the dominant observed response was due to the odd modes (i.e., the more efficient radiators). The error sensors in effect act as spatial wavenumber filters and only observe those components that contribute significantly to far‐field sound radiation. Both position and number of piezoceramic actuators were varied during the test to determine the effects on control performance. A variety of test cases was studied for controlling sound radiation due to a disturbance both on and off resonance. Results from these experiments indicate that PVDF sensors and piezoceramic actuators (i.e., an “intelligent” structure) show much promise for controlling acoustic radiation from structures, to a large degree overcoming the need for error microphones in the far field. [Work supported by ONR/DARPA.]