A comprehensive unit cell model: a study of coupled effects in piezoelectric 1–3 composites

A ®nite element unit cell model for investigation of arbitrary loading conditions is developed for composites with periodic arrangements of continuous aligned ®bers. Special emphasis is placed on the formulation of the boundary conditions to allow for simulation of all modes of overall deformation arising from any arbitrary combination of mechanical and electrical loading. The model is applied to piezoelectric composites whereby the overall elastic, dielectric, as well as piezoelectric moduli are fully extracted. The boundary conditions are validated for elastic in- plane shear loading and checked by recourse to comparisons with analytical bounds as well as semianalytical bounds and experimental investigations for piezoelectric composites from the literature. Aspects of ®ber arrangement and di€erences between piezoelectric ceramic as well as polymer matrix composites reinforced with piezoelectric ®bers are discussed. 7