ON THE EFFECTIVE ELECTROELASTIC PROPERTIES OF PIEZOELECTRIC COMPOSITES CONTAINING SPATIALLY ORIENTED INCLUSIONS

Presented here is an analytical method for determining the effective e lectroelastic properties of piezoelectric composites containing spatia lly oriented inclusions. Both inclusion and matrix are assumed to be l inearly piezoelastic. The three-dimensional anisotropic inclusion meth od has been developed, and the explicit expressions for the electrosta tic tensors analogous to the Eshelby tensors for elastic ellipsoidal i nclusions have been obtained. With these tensors, analytical expressio ns for the electroelastic fields of the piezoelectric composite can be established. Based upon the Mori-Tanaka mean field theory to account for the interaction between the inclusions and matrix, the effective e lectroelastic properties (elastic, piezoelectric and dielectric consta nts) of the composites are expressed analytically in terms of phase pr operties, orientation angles, volume fraction and shape. Numerical res ults have been given for a BaTiO3/PZT-5H composite. The results indica te that the proposed methods yield identical results whether a tractio n-electric displacement or an elastic displacement-electric field is p rescribed on the composite boundary is self-consistency. The electrome chanical coupling due to the piezoelastic effect is found to be strong ly affected by both the volume fraction and the orientation of inclusi ons. (C) 1997 Elsevier Science Ltd.