Piezoelectric transversely isotropic matrix containing spheroidal piezoelec
tric inclusions with different properties and of, generally, diverse aspect
ratios is considered. A full set of ten effective electrostatic constants
is derived, using the method of effective field. The case, when the inclusi
ons are circular cylinders (fibers) is analyzed in detail. The results are
compared with those of several earlier works. They constitute the theoretic
al framework for the design of piezocomposites with prescribed overall prop
erties.