Vibration Characteristics for Piezoelectric Cylinders Using Amplitude-Fluctuation Electronic Speckle Pattern Interferometry

Abstract

Electronicspecklepatterninterferometry (ESPI)isafull-e eld,noncontacttechniqueformeasuringthedeformation of a structure subjected to static loading or, especially, to dynamic vibration. Three-dimensional vibrations of piezoelectric materials with cylindrical surfaces are investigated using the amplitude-e uctuation ESPI (AF-ESPI) method. This method demonstrates the advantages of combining noise reduction, like the subtraction method, and high fringe sensitivity, like the time-averaged method. The optical system for AF-ESPI with two in-plane and one out-of-plane measurements is employed to study the volume vibration of a piezoelectric material for a thick circular disk, a ring, and a thin-walled tube. Because the clear fringe patterns measured by the AF-ESPI method will be shown only at resonant frequencies, both the resonant frequencies and the complete vibration mode shapes in three dimensions are obtained experimentally. Finally, impedance analysis and the e nite element method are also utilized, and the results are compared with the measurements obtained by AF-ESPI. It is shown that the numerical calculations and the experimental results agree fairly well for both the resonant frequencies and the mode shapes in three-dimensional cone gurations.