Energy Harvesting from Two Coupled Beams with Piezoelectic Patches

Abstract

This paper presents the problem of energy harvesting from two coupled beams using piezoelectric patches. The energy harvester is subject to both harmonic and random excitation. The voltages across the piezoelectric patches are measured in real time in order to calculate the power. The coupling between the beams is an important factor for harvesting energy for a wider frequency band because new modes appear with this effect. This would result in widening the frequency bandwidth in which the energy can be harvested. Both numerical and analytical models are developed for the two coupled beams with two different lengths. The natural frequencies and mode shapes are derived and the harvested power is calculated for the random excitation. The resistance of the two piezoelectric patches is varied and the optimum resistance is derived. Experiments are carried out on two coupled beams to obtain the performance of the harvester to demonstrates the increase of the frequency bandwidth in which the energy can be harvested. It is shown that the harvester can collect energy at a wider frequency bandwidth compared to a single beam.