Characterization of an energy sink based vibro-impact energy harvester with piecewise linear Stiffness : Modeling and experimental validation

In this paper, we introduce and characterize a vibro-impact electromagnetic energy harvester (VIEMH) with two-degree-of-freedom (2DoF) based on a nonlinear energy sink. The collision mechanism in the harvester induces an amplitude truncation effect, broadening its working bandwidth. The theoretical model utilizes a piecewise linear function to depict the collision action and employs the averaging method for an analytical solution. Theoretical analysis explores the influences of system parameters and the collision gap on VIEMH output performance. Experimental validations support the analytical results, indicating that optimal parameters (cantilever beam and spring stiffness) significantly enhance the amplitude and width of the two resonance peaks, resulting in improved performance. Under identical parameter settings (the cantilever beam and spring stiffness set at 355 N/mm and 0.005 N/mm, respectively), the working bandwidth of the system with collision is 7.95 times higher than that without collision. © 2024 Elsevier Ltd.