Optimization for the Harvesting Structure of the Piezoelectric Bimorph Energy Harvesters Circular Plate by Reduced Order Finite Element Analysis

Abstract

The power generation efficiency of piezoelectric energy harvesters is dependent on the coupling of their resonant frequency with that of the source vibration. The mechanical design of the energy harvester plays an important role in defining the resonant frequency characteristics of the system and therefore in order to maximize power density, it is important for a designer to be able to model, simulate and optimize designs to match new target applications. This paper gives a detailed calculation of piezoelectric energy harvesters that is in the form of a bimorph-circular plate fixed in the contour in the device frame by finite element (FE) analysis using the commercially available software package ANSYS, ACELAN. The piezoelectric bimorph is assumed to be driven into flexural vibration by an ambient acoustic source to convert the mechanical energies into electric energies. The optimal design was based on matching the resonant frequency of the device with the environmental exciting frequency, and balancing the output voltage. The simplified models of the account of a proof mass are offered. On the basis of calculations, the most effective construction of the device is offered that exhibit the targeted resonant frequency response chosen by the designer.