Modeling and Analysis of Galfenol Nonlinear Cantilever Energy Harvester With Elastic Magnifier

Abstract

To improve low-frequency broadband performances of a traditional cantilever energy harvester (TCEH), a nonlinear CEH (NCEH) with elastic magnifier (EM) (NCEH + EM) is studied. Based on the constitutive equations with the variable piezomagnetic coefficient, Faraday law, dynamic equilibrium, and harmonic balance theories, the two-degree-of-freedom lumped parameter nonlinear coupled model of NCEH + EM is established and the frequency analytical expressions are derived. Comparisons between the calculated and measured results show that the model can describe the nonlinear behaviors of TCEH. Simulated results show that the designed hard-spring NCEH + EM with two resonant frequencies can magnify low-frequency vibration amplitude, thus can lie in the high-energy orbit, and can generate much higher voltage and power than TCEH and NCEH in the broader low frequency range.