Full-Field Three-Dimensional Volume Vibrations for Piezoceramic Materials in Resonance

Abstract

Three-dimensional volume vibrations for piezoceramics, which couple the out-of-plane and in-plane vibrations, are investigated by using an optical interferometry method called the amplitude-fluctuation electronic speckle pattern interferometry (AF-ESPI). The optical systems for AF-ESPI with out-of-plane and in-plane measurements are employed to analyze the volume vibration of piezoceramic material for a rectangular parallelepiped configuration. Because the clear fringe patterns measured by the AF-ESPI method will be shown only at resonant frequencies, both the resonant frequencies and the corresponding vibration mode shapes are successfully obtained at the same time. Two out-of-plane and two in-plane measurements are needed to construct the complete information of vibration mode shape. However, by tilting the specimen with an angle, the coupled out-of-plane and in-plane motions can be obtained from only one out-of-plane setup and measurement. The dominant motion of the volume vibration can be identified from the mode shape by tilting the specimen. Finally, the impedance analysis and finite element method with three-dimensional model are also utilized, and the results are compared with the measurements by AF-ESPI. Excellent agreements of the resonant frequencies and mode shapes are obtained from both results. .