Micromechanics determination of electroelastic properties of piezoelectricmaterials containing voids

This paper examines the electroelastic properties of piezoelectric material s that contain voids. A unified micromechanics approach is adopted for dete rmining the properties. Voids are treated as spheroidal inclusions with zer o elastic moduli. The surrounding material is assumed to be linearly piezoe lastic and transversely isotropic. The electroelastic Eshelby tensors for s pheroidal inclusions have been evaluated numerically for different aspect r atios. Utilizing these tensors and applying the Mori-Tanaka mean field theo ry that accounts for the interaction between inclusions and matrix, the eff ective electroelastic properties of the materials are obtained. Numerical e xamples are given based oil PZ-T-5H and BaTiO3. Influences of the volume fr action and aspect ratio of voids on the material properties have been studi ed. Emphasis has been placed on the piezoelastic coupling effect of the mat erial. For both materials, the piezoelastic coupling provides a stiffening effect on the materials, and the influence is more pronounced when void vol ume increases and when the aspect ratio of voids becomes shorter. (C) 2000 Elsevier Science S.A. All rights reserved.