The effect of distance and dimensions of magnets on nonlinear behavior of piezomagnetoelastic bimorph energy harvester

This paper presents the effect of distance and dimensions of magnetson chaotic behavior and voltage level of a vibratory piezo-magneto-elastic bimorph energy harvesting system. The bimorph model comprises two iezoelectric layers on a cantilever base structure with one tip magnet as well as two external magnets. The mathematical model is extracted by using distributed model. The validity of the extracted model verified by previously published experimental results.In order to study the nonlinear dynamic of the bimorph, bifurcation diagram, phase plane portrait, time history response, Poincare map, power spectra diagram, and maximum Lyapunov exponents are used. In the bifurcation diagrams, the control parameters are the distances and dimensions of the magnets. It is shown that in the specific region of the control parameters, the sub-harmonic or super-harmonic behavior has minimum harvested voltage and irregular regions has maximum voltage. Also specific dimensions of tip magnet can influence greatly the dynamic behavior as well as output voltage. So these obtained results can give good insights about parameters identification and realization of the nonlinear behavior to reach the broadband higher harvested voltage of the system