Design Method And Experimental Study Of Particle Damping Structure Based On Phonon Crystal Theory

As a new artificial periodic structure,Phonon crystals have been widely used in many engineering application field.The Phonon crystals are subjected to the following factors,such as overlarge size of Bragg type phonon crystal,material properties and complex manufacturing process of Local resonance phonon crystal,making it difficult to use in the practical engineering.Recently,particle damping has attracted lots of attentions,providing a new way for the vibration reduction of plate and shell structures.Despite the significant advantage of the particle damping,such as large damping ratio and high temperature resistance characteristic,the application of the particle damping is further suppressed due to the effect of high nonlinearity characteristic and imperfect theoretical study.Through combining the vibration reduction mechanism,a new type particle damping phonon crystal structure is designed to suppress the vibration transmission of large-scale structure under complex and severe working conditions.Then,noise and vibration reduction of plate and shell structures in engineering can be realized smoothly.In this article,combining the formation cause of bandgap,modal theory and particle damping vibration reduction technology,a new type particle damping phonon crystal structure was developed.By using the numerical simulation and experimental test method,the formation process and acoustic vibration characteristics of the bandgap are studied in detail.The main research results are given as follows:The plate structure was adopted as a research object.From the dynamic point of view,the bandgap characteristics for the infinite periodic structures and finite periodic structures were analyzed by combining the modal resonance theory.Additionally,the effect of the structure and material parameters on the bandgap were discussed in detail.Based on the research results of the forced vibration,energy consumption law was analyzed by using the discrete element method.Combining the damping model characteristics,the equivalent calculation method of elastic discrete structure was established,which laid a theoretical foundation for the study of vibration characteristics of particle damping phonon crystals.Based on the mode resonance bandgap theory and equivalent analysis method,the physical model of particle damping type phonon crystal was established.The bandgap mechanism and damping characteristics of periodic structure and low-order modal structures for the particle damped phonon crystals were systematically studied.The experimental test was also verified,and also the design principle of particle damped structure was put forward.According to the vibration reduction requirements of ship structure,the particle damping structure was designed to satisfy the engineering application.The amplitude of average vibration reduction can reach 50%.The application of particle damping type phonon crystal structure in ship engineering was explored.This study can put forward many meaningful guidance suggestions for the engineering application of particle damping.In summary,the constructed damped type phonon crystal structure has excellent low-frequency vibration reduction characteristic.It is suitable for vibration and noise reduction of ship,aerospace plate and shell structures.Also,the proposed equivalent analysis method has extremely important theoretical significant and practical engineering application.