Research On Vibration Control Based On Piezoelectric Metamaterials

Piezoelectric metamaterials have become one of the hot research topic in vibration/noise attenuation domain in recent decades due to the unusual bandgap properties,more and more attention have focused on the local resonance(LR)band gap based on inductance-capacitance(LC)resonance.However,the LR bandgaps of piezoelectric metamaterials are usually narrow due to the LC resonance mechanism,which significantly limits their practical applications of vibration/noise control.Therefore,in order to achieve bandgaps at broadband frequencies,more effective control methods should be investigated.In this dissertation,taking bandgap of piezoelectric metamaterials as the object of research,passive,semi-active,and active control methods are applied to investigate the bandgap control,and the theoretical model of piezoelectric metamaterials is established.Parameter optimization and the influence of circuit parameters on bandgap are discussed,which provides a possibility for the application of piezoelectric metamaterials in vibration/noise control.The major work of this dissertation is presented as follows:(1)The calculation methods of bandgap and transmission characteristics of piezoelectric metamaterials are investigated,the piezoelectric metamaterials model is established based on long wave hypothesis and integral hypothesis.The transfer matrix of elastic wave propagation in structures is calculated based on the model.Finally,the band gap and transmission characteristics of piezoelectric metamaterials are predicted by the transfer matrix.(2)The band gap control method based on passive shunt circuit is proposed,the numerical simulation is used to analyze the causes and effects of the parameters in RLC circuit on bandgap,and the verification experiment was made for bandgap,which proves the accuracy of simulation results.Finally,the optimization method of bandgap is analyzed to propose a possible solution to broaden the bandgap.(3)The bandgap control method based on semi-active non-linear synchronous switch technique is presented.Firstly,a new self-sensing semi-active control circuit is proposed by introducing negative capacitance,which satisfies low-power and miniaturization.Furthermore,the stability of the circuit is systemically analyzed by theoretical derivation studied with practical experiment.Subsequently,based on the proposed circuit,piezoelectric metamaterials with semi-active non-linear synchronous switching circuits are designed.To facilitate making the theoretical analysis,a new equivalent linearization method is used to analyze the nonlinear circuit.Finally,the numerical simulation results show that the bandwidth of the bandgap can be broadened by the nonlinear circuit,and the negative capacitance can enhance the suppression effect.(4)The research of synthetic impedance technology is intended,and the equivalent control loop of synthetic impedance is designed.The simulation results show that the method can flexibly adjust the bandgap of piezoelectric metamaterials by software programming,and avoid the effects of uncertainties of component parameters on the performance.