Enhanced nonlinear energy harvesting using combined primary and parametric resonances: Experiments with theoretical verifications

Presented in this paper is harvested nonlinear energy from a vibration energy harvester device; the device has been designed, manufactured, and tested successfully – the device performance is verified theoretically to some extent. The design concept is on the basis of merging the nonlinearities of the building block (i.e. a beam) and those induced by the motion limiters, which for some design parameters leads to the combination of parametric and primary resonances of the device; these two resonances increase the operational frequency bandwidth by 118%. By introducing motion limiters to the proposed system, the overall frequency bandwidth of the primary and parametric resonances is able to be broadened even more – up to 178%. By varying the angle between the base (ambient) excitation and the length of the core element; the optimal angle for the largest possible frequency bandwidth is obtained. Theoretical investigations including the finite element method (FEM) using ANSYS and an averaging perturbation technique have been performed to verify the experimental results for few cases. An experimental parametric study on the performance of the device has also been conducted to highlight the limiter gap and type as well as orientation angle effects.