A unified model for piezocomposites with non-piezoelectric matrix and piezoelectric ellipsoidal inclusions

In this paper, the closed-form solutions of the electroelastic Eshelby's te nsors of a piezoelectric ellipsoidal inclusion in an infinite non-piezoelec tric matrix are obtained via the Green's function technique. Based on the g eneralized Budiansky's energy-equivalence framework and the closed-form sol utions of the electroelastic Eshelby's tensors, a unified model for multiph ase piezocomposites with the non-piezoelectric matrix and piezoelectric inc lusions is set up. The closed-form solutions of the effective electroelasti c moduli of piezocomposites are also obtained. The unified model has a rigo rous but simple form, which can describe the multiphase piezocomposites wit h different connectivities, such as 0-3, 1-3, 2-2, 2-3, 3-3 connectivities, etc. It can also describe the effects of non-interaction and interaction am ong the inclusions. As examples, the closed-form solutions of the effective electroelastic moduli are given by means of the dilute solution for the 0- 3 piezocomposite with transversely isotropic piezoelectric spherical inclus ions and by means of the dilute solution and the Mori-Tanaka's method for t he 1-3 piezocomposite with two kinds of transversely isotropic piezoelectri c cylindrical inclusions. The predicted results are compared with experimen tal data, which shows that the theoretical curves calculated by means of th e Mori-Tanaka's method agree quite well with the experimental values, but t he theoretical curves obtained by the dilute solution agree well with the e xperimental values only when the volume fraction of the ceramic inclusion i s less than 0.3. The results in this paper can be used to analyze and desig n the multiphase piezocomposites. (C) 1999 Elsevier Science Ltd. All rights reserved.