Numerical characterization of piezoelectric energy harvesting from an L-shaped frame

Abstract

An L-shaped structure, intended for piezoelectric energy harvesting, is being characterized numerically to obtain extended insight into the effect of various parameters and metrics that are hard to track from experimental setups and simplified analytical models and to show the underlying mechanism of efficient piezoelectric harvesting. A numerical model was developed to analyze the structure under harmonic base excitation to obtain voltage frequency response and strain distribution data. The model takes into effect the load resistance applied between the piezoelectric patch electrodes and the damping ratio of each mode for accurate resonance amplitude evaluation. The validity of the model was confirmed by comparisons with previous experiments and showed strong agreement. The approach demonstrated that piezoelectric energy harvesting modeling, in general, is sensitive to inaccurate estimations, especially in the damping parameters, which emphasizes that rough assumptions made in analytical models will not yield results that can be discussed in correlation with experimental outcomes. This work states the guidelines for accurate piezoelectric modeling using numerical software, with the aim of enabling the investigation of complex harvesters, providing more insights to direct researchers to more proof and optimized designs that tackle broadband and energy density problems found in simple harvesters.