Energy harvesting from a nonlinear piezoelectric oscillator subjected to random and harmonic excitations
Pereira, T. L. Pereira1; De Paula, A. S. De Paula1; Fabro, A. T. Fabro1; Savi, M. A. Savi2
1 Universidade de Brasília; 2 Universidade Federal do Rio de Janeiro
Baixar PDF doi:10.20906/CPS/CILAMCE2015-0444
Resumo
Many alternative energy sources have been investigated in the last decades, energy harvesting from the environment is of these possibilities and have been explored recently by using piezoelectric material. This vibration-based energy harvesting using piezoelectric elements is possible by exploring the direct effect, where the piezoelectric material is able convert mechanical in to electrical energy, and can be very useful for applications in powering small electronic devices. Analyses involving oscillators subjected to harmonic excitations have been well studied, demonstrating that nonlinearities can enhance the harvested energy, mostly the nonlinearities that lead to bistable oscillators. This work addresses the influence of nonlinearities in energy harvesting from a piezomagnetoelastic structure subjected to random and harmonic vibrations. The energy harvesting system is a magnetoelastic structure that consists of a ferromagnetic cantilevered beam with two permanent magnets, one located in the free end of the beam and the other at a vertical distance d from the beam free end, subjected to random base excitation. In order to use this device as a piezoelectric power generator, two piezoceramic layers are attached to the root of the cantilever and a bimorph generator is obtained. Nonlinear equations of motion that describe the electromechanical system are given along with theoretical simulations. The numerical analysis presents a comparison between the voltage provided from nonlinear system due to random and harmonic excitations. The goal of the analysis proposed in this work is to establish appropriate excitations that to lead to the increase of power output in vibration-based energy harvesting system subjected to harmonic and random excitations.
Palavras-chave: Energy Harvesting ; Non Linear; Random Vibration