窄带随机激励下三稳态压电俘能器的动力学特性与实验研究

In this paper, the dynamical behaviors of a tri-stable piezoelectric energy harvester under the narrow-band random excitation is studied. Firstly» the dynamical equation of a tri-stable nonlinear canti lever piezoelectric energy harvesting system is established. The analytical expressions of the dynamical response of the system together with the first and second steady moments arc obtained by using the mul tiple scales method. Secondly, the effects of the distance between the tip magnet and the external mag nets ？the noise intensity and the excitation amplitude on the system response and harvesting performance are discussed. The obtained results show that as the noise intensity increases, the piezoelectric vibration energy harvester will experience mono-stable, bi-stablc and tri-stable motion. Changing the horizontal and vertical spacing of the magnets makes the piezoelectric energy harvester perform tri-stable motion, and the displacement and acquisition voltage arc significantly improved compared to the bi-stablc case. Finally, the collection performance of the piezoelectric energy harvester in different configurations is compared through experiments.The results show the superiority of the tri-stable piezoelectric energy har vester, which provide the theoretical support for the design of the vibration energy harvester under the narrow-band random excitation.