A magnetically coupled nonlinear T-shaped piezoelectric energy harvester with internal resonance

摘要

This letter originally presents a magnetically coupled nonlinear T-shaped piezoelectric energy harvester with multiple resonance bands based on internal resonance principle. The proposed harvester consists of a clamped-clamped buckled beam and a vertical cantilever with tip magnetically coupled. The corresponding theoretical model is established. Two resonance bands with hardening nonlinear phenomenon are obtained. 1:2:3:4 internal resonance characteristics with the peak amplitude ratio of 1:1.81:0.56:0.31 are found for the generated voltage of the first resonance. The energy conversion efficiency can be enhanced by utilizing high frequency response under low-frequency excitations. The bandwidth of full width at half maximum output power reaches 13.8 Hz within the excitation between 5?30 Hz. The response of random excitations is also investigated and an average power of 9.64 ?W is achieved at the random excitation intensity of 0.001 g(2)Hz(?1). Overall, the proposed harvester can achieve ultra-wide working frequency range under low-level excitations and is suitable for low-frequency random vibrations.