Broadband vibratory energy harvesting via bubble shaped response curves

Abstract

This paper concerns an investigation into the characteristics of a linear-nonlinear coupled electromagnetic energy harvester. The nonlinear oscillator consists of a linear (mass-spring-damper) oscillator with two additional horizontal springs. It is assumed that the vibration is restricted to one direction of harvesting mass to which the parallel magnetic field is induced. Of interest here, however, is the bubble shaped response curves for the amplitude- frequency response, and its potential benefits on the energy harvesting. The Harmonic balance method is used to analysis the power amplitude-frequency response of the system. It is found that the linear and nonlinear resonances could interact with each other at moderate excitation levels, so bubble shaped response curves are formed. The benefits of the nonlinearity on the energy harvesting are achieved. The results are also validated by some numerical work. Then the averaged power under Gaussian white noise is also calculated numerically, the results demonstrate that the bubble shaped response curves design produces more power than other designs under random excitation.