Effective properties of composites utilising fibres with a piezoelectric coating

Composites with piezoelectric fibres are promising new materials, combining the beneficial properties of very different constituents. Recently hybrid fibres with an inactive core and a piezoelectric coating have been developed. For conventional two-phase systems the correlation between component properties and effective composite behaviour is well approximated using effective field or self-consistent models. Since the latter approaches are commonly based on solutions for homogeneous inclusions, they cannot be directly employed for heterogeneous particles as coated fibres. Different methods are employed to estimate the relevant effective electromechanical parameters of composites continuously reinforced with coated piezoelectric fibres: (a) a unit cell finite element model, (b) an effective field approach built on a rigorous solution for a coated fibre in an infinite matrix and (c) a simple homogeneous field approximation. The results of the approaches are compared and discussed.