Today, the vibration analysis of laminated structures represents an important field in engineering metrology. The experimental measurement of the resonant frequencies for the piezoceramic material is generally performed by impedance analysis. However to perform full-field, non-contact, and real-time measurement, optical methods are a preferable choice.
Recently, interesting results have been obtained by Electronic Speckle Pattern Interferometry (ESPI). In this paper, we report an alternative electro-optical system based on local digital speckle correlation. This new method permits the development of an instrument that is cheap, safe and easy to use. We employ the proposed method to investigate the vibration characteristics of piezoceramic/nickel-alloy laminated plate. The circular membrane is a composite made of a nickel alloy disk with thickness 0.1 mm and diameter 30 mm, to which a piezoceramic disk, with the same thickness and a smaller diameter (24 mm) is bonded. A brief analysis of the technique and some experimental results are presented. Finally, the numerical finite element calculation is also performed, and the results are compared with the electro-optical measurements.