Analysis of microstructural fields in heterogeneous piezoelectric solids

A theory is developed to analyze the internal fields in heterogeneous piezoelectric solids. It is used to derive expressions for mean values and variations of the internal fields due to external loading and eigenfields. The general theory is applicable to both polycrystalline ceramics as well as matrix-based composites. After the general development,the theory is applied to multiphase matrix-based piezoelectric composites, and explicit relations are obtained for two-phase composites. Exact connections are established between the-effective thermal properties and the effective electroelastic moduli, and these agree with previous results of Benveniste [3] and Dunn [15] obtained by two different approaches. The stored enthalpy of the heterogeneous solid is also expressed as an explicit function of the effective thermoelectroelastic properties. Finally, to demonstrate the applicability of the theory, numerical results for average fields and field variations are presented for a two-phase composite consisting of continuous piezoelectric fibers embedded in a polymer matrix. (C) 1999 Elsevier Science Ltd. All rights reserved.