PIEZOELECTRIC EFFECT IN COMPOSITES WITH DIFFERENT POLING DIRECTIONS CONSTITUENTS

摘要

In a state of shear piezoelectricity, properties enhancement are found. They are related to the shear piezoelectric constant in a periodic fibre-reinforced composite whose constituents have transversely isotropic electroelastic properties found in ceramics like Barium Titanate and PZT-7A. Closed-form expressions for the effective properties of this kind of composite derived recently, by means of the asymptotic homogenization method, are used to gain further insight into the effect of the constituents poling directions. A composite with like materials, but with opposite poling directions, display an augmented characteristic for any fibre volume fraction. The stiffening and higher permittivity can be as 23% larger than that of the single material property itself for Barium Titanate. Other related results are given.