Research On Vibration Characteristics Of Shaft And Thin Circular Plate Of Piezoelectric Phononic Crystals

Elastic wave can exhibit unique dynamic characteristics when propagating in phononic crystals(PCs).For example,elastic waves can be strongly suppressed within some frequency bands called “band gaps”,providing an effective way for people to control the spread of wave propagation.As a functional material,piezoelectric ceramics has obtained a widespread attention because of its electromechanical coupling characteristics.And it has become a hot issue to untilize piezoelectric PCs to solve prevalent mechanical vibration problems in many engineering field.In this thesis,we construct two kinds of structures,i.e,piezoelectric PC shaft and piezoelectric PC thin circular plate by introducing piezoelectric material into the design of shaft and plate.Based on the theoretical analysis,vibration characteristics of the two structures are researched deeply using numerical analysis and finite element method.The main work in this content is as follows:1.The first chapter is introduction.Concept of PC and quasi-PC is introduced.Current status of the research of PC and quasi-PC is summarized.Research significance and content of this thesis is also described.2.In the second chapter,the control equation of torsonal vibration of piezoelectric PC shaft is derived theoretically.Using transfer matrix method,numerical analysis of torsonal vibration characteristics of piezoelectric PC shaft and Quasi-PC shaft is analyzed and the results of them were compared.3.In the third chapter,piezoelectric PC thin circular plate of patch type and FB piezoelectric PC thin circular plate of embedded type are researched.Band gaps of bending wave in these two kinds of structures and effects of key parameters on the band gaps are studied.4.In the forth chapter,radial vibration characteristics of both embedded type piezoelectric PC and Fibonacci PC thin circular plate are researched.In addition,the effect regulation of electrical open circuit,electrical short circuit,polarize direction of piezoelectric ceramic on the band gaps is also analyzed.5.The fifth chapter is experiment.Appropriate experimental model is designed and the experiment system is set up.Using vibration analysis system and multi-function control system of piezoelectric ceramic,bending vibration characteristics of patch type piezoelectric PC thin circular plate is verified.