NONLINEAR PARAMETRICALLY EXCITED ENERGY HARVESTERS

The study explores enhancing vibrational energy harvesting through parametric resonance, demonstrating that integrating auxiliary sub-structures can yield large-amplitude and broadband features. In some cases, multi-stability and multi-directional characteristics can also be obtained. This approach also attempts to trigger the unstable region of the principal parametric resonance of piezoelectric beams under small base excitations. The governing equations of this system are derived using the extended Hamilton principle and solved using perturbation methods like the Harmonic Balance Method. Experiments are carried out to validate the theoretical findings. The results highlight the advantages of using linear/nonlinear auxiliary sub-structures in the resonant regime to enhance the performance of cantilever-based vibration energy harvester via parametric excitations.