On the effective properties of thermo-piezoelectric matrix composites

Explicit expressions for the effective pyroelectric, dielectric, piezoelect ric, elastic and thermoelastic constants of a matrix composite have been ob tained in closed form. A numerical analysis has been carried out of the con centration dependences of constants of a composite in which the BaTiO3 cera mics is the matrix while the inclusions are represented by spheroidal ceram ic particles of PZT-19. A case is examined when the matrix and the inclusio ns possess opposite polarization. At a certain concentration of PZT-19 the composite exhibits well pronounced pyroelectric properties without having a ny appreciable piezoeffect. At another concentration, it manifests marked p iezoelectric properties, but does not possess the pyroeffect. Practical imp lementations of the results are discussed.