Numerical modelling of micro energy harvesting systems based on piezoelectric composites polarized with interdigitated electrodes

Abstract

This paper focuses on the numerical modelling of micro-energy harvesting systems(MEHSs) based on piezoelectric composites polarised with interdigitated electrodes (PCPIE). The system response and the harvested energy are numerically assessed using a multilayer piezoelectric shell finite element (FE) with a uniform fibre aligned electric field (UFAEF) in each active layer. Circuit and compatibility equations are included to take into account the presence of the electrical network. A state-space (SS) model is derived and used to evaluate the effect of electrical impedance on damping and natural frequencies, as well as dissipated energy/power. An energy harvester beam with a piezoelectric macro fibre composite (MFC) patch is first modelled with the developed tools. Numerical results are found to be in good agreement with experimental results reported in the literature. Finally, a MEHS consisting of a closed-box beam equipped with PCPIE devices bonded to its skin is analysed. The structural system is subjected to dynamic loading imposing oscillating displacements and deformations compatibles with those expected during service-life. Numerical results show the influence of the electrical impedance on system response, damping, natural frequencies, and electrical power.