Numerical Analysis of Superharmonic Resonance in Electromagnetic Vibration Energy Harvester with Ball Impacts

Abstract

The superharmonic resonance of a cantilever beam subject to mechanical ball impacts is investigated numerically for potential vibration energy harvesting. In our device, a multipole magnet array attached on the cantilever moves above a planar coil array fixed on the baseplate of the device, leading to power generation through electromagnetic induction. In the numerical model, the cantilever is assumed to be a single DOF damped mass-spring system, which is coupled with the translational motion of a point mass through the classical collision model. The Fourier amplitudes of the cantilever’s displacement have been obtained and compared with the experimental results. It is found that the numerical solution of the superharmonic components shows quantitative agreement with the experiment in the low-frequency range associated with human-induced motions. The excitation region of the superharmonics has been represented as a function of the excitation frequency and the gap distance of the ball motion.