Dual Function Study Of Piezoelectric Energy Harvester Based On Vibration Absorber

In recent years,it has becomes one of the research focus that piezoelectric energy harvesting scavenges vibrational energy and converts it to electric power for sensor networks and wireless device.Vibrational energy is widely present in multifarious engineering applications,and there are harmful vibrations caused by resonances or Hopf bifurcation.Therefore,it is of great significance to research the piezoelectric energy harvester in combination with the vibration absorber for vibration control and energy harvesting.At present,most of the studies on piezoelectric energy harvester are focused on the optimization of acquisition ability,which is less used in vibration absorption.In this paper,two piezoelectric energy harvesters are studied based on the vibration absorber.One is a autoparametric piezoelectric energy harvester that is designed based on nonlinear "saturation" principle and a 1:2 internal resonance.The other is a fusiform piezoelectric energy harvester by using dynamic vibration absorber.Based on Hamilton's principle and Gauss' law,the distributed parameter model of these two piezoelectric energy harvesters are established respectively.For the mathematical model of the autoparametric piezoelectric energy harvester,the harmonic balance method and the method of multi-scale are used to decouple the original governing equation and obtain the approximate analytical solution.In order to complete the synergistic study of dual-function of vibration control and energy harvesting,the optimal conditions for controlling the displacement of the main structure by the autoparametric piezoelectric energy harvester are given from the analytical solution.From the numerical solution of the fusiform piezoelectric energy harvester,it is found that the optimization of dual-function is realized by adjusting the load resistance and the tip mass.By studying the performance of these two piezoelectric energy harvesters at constant excitation frequency and amplitude,it is found that they can not only effectively control the vibration of the main structure in the resonance region,but also the secondary structure is not directly affected by the main structure and reduce the effect of energy harvesting.It is found that the bifurcation phenomenon exists through the study of the numerical solution,and the system experiences periodic motion,aperiodic motion and chaos from stable region to unstable region.The control of the base structure becomes ineffective in the unstable region.Finally,the experimental device of the autoparametric piezoelectric energy harvester was designed and fabricated.Through a series of experiments,the 1:2 internal resonance phenomenon in the system was verified.The harvested power in the theoretical results is in good agreement with the experimental data,thus verifying the theoretical model.Based on the theoretical model of the fusiform piezoelectric energy harvester,the simulation model was established in the finite element software.The dynamic characteristics analysis and multiphysics coupling analysis were carried out.The theoretical model of the fusiform piezoelectric energy harvester is verified by comparing the theoretical results with the simulation results.