Finite element characterisation of multilayer d(31) piezoelectric macro-fibre composites

摘要

This work presents a methodology for the numerical characterisation of the effective properties of a d(31) macro-fibre composite (MFC) transducer and their electric field dependence. This is done first by using a finite element homogenisation methodology proposed previously for shear d(15) MFC to evaluate the effective properties of a d(31) MFC based on known geometrical and material properties of its constituents, accounting in particular for the effect of electrode and protective layers on the effective elastic, piezoelectric and dielectric coefficients. Obtained results for the active layer agree very well with previously published ones obtained using mixing rules techniques, while obtained results for the full 5-layered MFC agree very well with properties provided by the manufacturer. Then, an analysis of the effect of the fibre volume fraction and electric boundary conditions on the main effective properties is presented. Next, experimental data describing the electric field dependence of soft piezoceramic fibres dielectric and piezoelectric properties are used to develop electric-field dependent material models. Finally, the homogenisation technique is performed for various electric field values to evaluate the electric field dependence of the effective d(31) MFC properties. It is shown that effective piezoelectric and dielectric coefficients may vary substantially with electric field. (C) 2015 Elsevier Ltd. All rights reserved.