Coupled thermo-electric-magnetic-elastic strongly nonlinear energy harvesting and dynamic analysis from multi-source excitations

Abstract

Energy harvesting technology application scenarios have been broadened to multi-source excitations, including thermal, magnetic, and vibration, but the coupled multi-field effect makes the system response more complicated. In this paper, to analyze the response of the coupled multi-field system, theoretical modeling of the coupled thermo-electric-magnetic-elastic strongly nonlinear energy harvesting system is constructed. Correspondingly, the modified Green's function method and harmonic balance method are deployed to determine the solutions of the coupled multi-field model. The derived closed-form solutions are verified. From the theoretical analysis, we get a conclusion that the triggered thermal stresses within the structure owing to the temperature gradient are simultaneously canceled out, which is the reason why thermal excitation is not considered in the coupled force equation. This study reveals the amplitude-dependent property of temperature distribution induced by magnetically induced interwell and intrawell oscillations, i.e., coupled temperature distribution. For a strongly nonlinear beam-type energy harvesting system, results indicate that the multi-solution area is determined by excitation amplitude, frequency, and structure parameters, which means that the closed-form solutions of interwell and intrawell oscillations do not exist simultaneously. To improve the power generation performance, it is important for the energy harvesting design to intentionally operate in high power generation regions. This study provides a fundamental understanding and reference framework for coupled thermo-electric-magnetic-elastic investigation and potential application.