Research On Vibration Characteristics Of Combined Phononic Crystal Rod

With the continuous development of industrial society, people become more and morestrict with processing and using of the precision instrument, it becomes a hotspot issue thathow to control vibration and noise cause the adverse effect on safety and environment aroundus in every research field. The theory of Phononic crystal (PC) is applied to the commonengineering structures, and the characteristics of band gaps are used to restrain vibration,which is becoming a new theoretical way to control vibration, and has important implicationsfor engineering practice.Under this circumstance, based on the theory of PC, combining with numericalderivation, Finite Element Method (FEM) and experiment, the purpose of this paper is toinvestigate the characteristics of the vibration band gaps in periodic combined rods which areapplied widely in engineering deeply and systemically. The main research contents are asfollows:1. The Transfer Matrices Method is used to research that how to influence thepropagation of coupled vibrations in different type of combined rods (angle rod and T rod).We build the mathematical modeling and theoretical derivation for them, and compute thecharacteristics of vibration transmission by Matrix Laboratory.2. The vibration simulation characteristics of combined rods are analysed by using FEM,and compare with the result of theoretical derivation. On this basis, we research the effectfactors of combined rods vibration band gaps, and summarize the laws.3. Design and prepare the PC combined rods samples, and vibration performance istested by using the vibration testing and analysis system, the experimental prove the results oftheory and simulation exact.The studies show that the vibration characteristics of theoretical derivation、simulationand experimental results are consistent. And the two types of PC can realize waveformtransformation by coupling effect of the bonding point, the different types of elastic waveband gaps can be used at the same time. So it shows the broadband and multi-dimensionalvibration characteristics. It’s better to apply to the engineering depressing vibration and noise.These studies which are valuable to promote the theory of PC application in the engineeringfield, as well as have reference values to vibration/noise control.