Investigating the performance of tri-stable magneto-piezoelastic absorber in simultaneous energy harvesting and vibration isolation

Abstract

Tri-stable magneto-piezoelastic oscillators exhibit superior performance in terms of broadband resonance frequency and lower excitation threshold, compared to linear and bi-stable systems. Furthermore, inclusion of magnets renders them applicable, tunable, and simple designs. However, the potential of this oscillators for the purpose of simultaneous vibration suppression and energy harvesting has not been investigated. This study aims to investigate simultaneous energy harvesting and vibration isolation through a tri-stable magneto-piezoelastic absorber (TMPA). The absorber comprises a bimorph cantilever beam carrying a magnetic tip mass and two external magnets. The interplay between magnets generates a nonlinear restoring force in the TMPA structure. This absorber is attached to a host vibrating beam, which is under a transient or periodic forcing, in order to reduce its vibrations and harvest electrical energy. The nonlinear magneto-electromechanical equations governing the coupled system are obtained by employing the Hamilton's principle, Euler-Bernoulli beam theory, and a recently proposed magnetic force relationship. First, the mechanisms of tri-stability formation are investigated via bifurcation diagrams. Next the potency of the TMPA in the transient excitation scenario is examined. Furthermore, the performance of the TMPA in the presence of the periodic excitation with different forcing levels is investigated. Specifically, frequency and time domain analyses are carried out to characterize the response of the system and efficiency of the absorber when TMPA performs periodic in-well, aperiodic inter-well and periodic inter-well oscillations. In addition, to provide a better insight regarding the TMPA performance, the kinetic energies, harvested power, and dissipated power for the region of strongly modulated response are also studied. Moreover, the efficacy of the TMPA in periodic snap-through oscillations is examined by the means of the harmonic balance method in conjunction with pseudo-arclength continuation scheme. Finally, the results disclosed that the proposed tri-stable absorber outperforms a linear absorber in vibration annihilation and energy harvesting.