Study On Coupled Resonance Of Liquid-Elastic Shells Coupled System

It is of great value to deal with liquid-solid coupling problems, which lie inengineering problems widely. With the development of the study, linear theory hasbeen perfect gradually and nonlinear problems have attracted more and moreexperts. The phenomenon that low-frequency and large-amplitude gravity wavesmay be generated by the external excitation with high frequency in liquid-elasticshells coupled system belongs to nonlinear vibration phenomenon, whosevibration mechanism is deeply studied in this paper. 1. Achievements and primary study methods on some major research topics are discussed in detail. The tendency of liquid-solid interaction mechanics development in the 21st century is also analyzed and suggested. 2. Because of the nonlinearity of boundary conditions, it is difficult to give a perfect model which is vital to clarify the mechanism thoroughly. Thus, in order to explain the phenomenon that low-frequency and large-amplitude gravity waves may be generated by the external excitation with high frequency in liquid-elastic shells coupled system, based on boundary conditions of the system and the liquid-solid coupling conditions, a set of nonlinear equations for the system is constructed with the use of the knowledge of hydromechanics and elasticity. 3. The numerical computation is carried out by the Runge-Kutta method and the time history curves and the amplitude-frequency curves are obtained, which present the primary analysis to explain the vibration mechanism that such phenomenon is the result of coupled resonance of the liquid-elastic shells coupled system. Only when the amplitude and the frequency of the excitation both satisfy the definite condition, will the phenomenon appear. 4. The theoretical analysis is carried out respectively by means of multi-scale method and averaging method. The relationship between the amplitude and the frequency of the external excitation and the response of the gravity ＩＩwaves is also established, which makes the vibration mechanism more clear. The results of two analytical methods are the same which show good agreement with the numerical result. 5. The bifurcation behaviors are discussed according to singularity theory. Many bifurcation models and transition sets are also obtained. The relationship between the system parameter and the bifurcation behavior is constituted, which supply the theoretical reference for designing and analyzing the system. On the basis of the numerical computation and the theoretical analysis, anin-depth study is given to explain the vibration mechanism of gravity waves in theliquid-elastic shells coupled system. Numerical results, analytical results andexperimental results show good agreement with each other.