Stopband-edge frequencies in the resonance spectra of piezoelectric periodic composite plates

The stopband-edge frequencies of periodic composite plates made of alternating elements of piezoelectric ceramic and epoxy resin are studied both theoretically and experimentally. A model is proposed for the transmission function of plates with a finite number of elements below their thickness resonance, and the results are compared with the electrically excited acoustical resonances of samples with different structural parameters (size and number of elements, and volumic fraction). The excellent agreement between theory and experiments supports possibility of using the present approach to tailor the resonance spectra of composites in the below-thickness regime by varying their structural parameters in a controlled way