Electromechanical response of 1-3 piezoelectric composites: Effect of fiber shape

An analytical model and a finite element based numerical model is presented to study the effects of fiber shape on the complete elastic, dielectric, and piezoelectric properties of a general 1-3 long-fiber "longitudinal" and "transverse" composite with elastically anisotropic and piezoelectrically active constituents. Six classes of piezoelectric composites, each with several prismatic and nonprismatic shaped fibers, in two widely different ceramic and polymer matrices are considered. It is demonstrated that (i) while the longitudinal material properties are insensitive to changes in the shape of the fiber phase, the transverse properties display a strong dependence on the shape of the fiber phase, particularly for the polymer-matrix composites; (ii) while the figures of merit such as the longitudinal piezoelectric coupling constant and the acoustic impedance do not demonstrate significant fiber shape effects, the transverse sensing ability of the polymer-matrix transverse composite is significantly influenced by the fiber shape with the composites with prolate shaped fibers providing the highest piezoelectric voltage constant.