Effects of geometric and material parameters on band-gaps of piezoelectric vibration energy harvesting plate with local resonators

摘要

Continuously powering wireless sensor nodes (WSNs) has been one key problem in structural health monitoring. Piezoelectric energy harvesting (PEH) from environmental vibrations has been a potential way to make low power consumption WSNs self-powered. One kind of vibration energy harvesting plate with local resonators embedded in piezoelectric patches is presented in this paper. Due to its distinct dynamic performances: band gaps, we can control wave propagating for the purpose of broad band vibration harvesting and higher energy conversion efficiency. Distributions and characteristics of band gaps are affected by geometric and material parameters, thus it's necessary to analyze the effects of these key parameters. In this paper, a theoretical calculation method of vibration propagation characteristics is developed based on finite element method (FEM) and the Floquet-Bloch theorem. Then finite element simulations using Comsol software are done to analyze the effects of different parameters. The results show that we can reduce the beginning frequency of the lowest band gap by increasing the length of resonators, while broadening band gaps by raising the filling ratio of the piezoelectric patches. On the other hand, Young modulus is the main factor of material parameters which markedly affects the beginning and cutoff frequency. The results provide useful theoretical guidelines for optimally designing vibration energy harvesting plates in applications.