Effective properties of platelet reinforced piezocomposites

Simple algebraic formulae are derived for estimates of the effective thermo-electroelastic moduli of multiphase platelet reinforced composites with the self-consistent and Mori-Tanaka methods. Specific results are given for the effective elastic, piezoelectric and dielectric constants, as well as the thermal stress tensor and pyroelectric constant. The platelets are modeled as very thin oblate spheroids in which the edge effects caused by the sharp corners are taken to be negligible. The results are formulated with the help of a polarization tensor for a piezoelectric platelet inclusion. It is shown that, although the two methods are different in nature, their estimates of the thermoelectroelastic moduli are exactly the same. When the piezoelectric coupling is absent, the results exactly reduce to those for uncoupled elasticity. Moreover, they exhibit the correct behavior in the low and high concentration limits. A number of exact results for a platelet inclusion are also established.