Predictions of Static Displacements in 1-3 Piezocomposites

Piezocomposites have demonstrated higher sensitivity and lower mechanical losses than single phase piezoelectric materials. As with any composite material, the properties and behavior of piezocomposites are highly dependent on the properties of the constituent materials and the interface between them. In this paper, the micromechanical behavior of 1-3 piezocomposites is investigated. An analytical model is developed for predicting the static displacement behavior of a single piezoelectric rod embedded in a matrix. In the model, the ceramic rod is treated as transversely isotropic since it has different piezoelectric coefficients in the longitudinal and transverse directions. It is proposed that presence of a thin interlayer or polymer coating around the ceramic rods can influence the longitudinal displacement of the rods and change the overall sensitivity. A composite cylinder model is adopted to incorporate the presence of an interlayer with varying properties. Theoretical predictions indicate that the introduction of a compliant interlayer greatly increases the out-of-plane displacement of the rod and the sensitivity of the composite.