INFLUENCE OF THE STRESS-TRANSFER ON THE DYNAMIC PROPERTIES OF THE 2.2PZT-POLYMER COMPOSITES

1.3 and 2.2 composites made respectively of PZT rods or lamella embedd ed in a polymer matrix have proven to be efficient materials for ultra sonic transducers. A new modelling approach, taking into account expli citly the stress transfer occurring at the PZT-polymer interface, is p roposed. This model allows the simulation of the main phenomena occurr ing in a composite unit-cell including one PZT element. The dispersion curves of the various thickness and lateral periodicity related modes are established. The theoretical results are compared with experiment al data obtained on 2.2 piezocomposite samples characterized both elec trically and with laser Doppler vibrometry.