| This paper is to study laminated composite thin-cylindrical shell filled with fluid. The boundary condition of shell is clamped-free. The dynamic elastic modulus of shell changes with the frequency of exciting force, the larger the frequency of exciting force is, the smaller the dynamic elastic modulus is. We calculate the natural frequencies of cylindrical shell filled with liquid by collocation method. Then study the nonlinear vibration of the system with numerical method and harmonic balance method.Firstly, the coupled nonlinear wave vibration equation considering the geometric nonlinearity of the FSI system is established by using Donnell’s shallow shell theory and potential flow theory. The nature frequencies are calculated by collocation method and compared with experimental data. The results show that the cylindrical shell contenting liquid makes the natural frequencies of cylindrical shells fall, and more water it contains, lower natural frequencies it has.Then, we discretize the wave equation by Galerkin method, and we obtain mutual coupling mode equations. We achieve the numerical solutions of the coupled system with the continuation-shooting method and obtain the whole amplitude-frequency characteristic curves which contain both stable and unstable part. We use Floquet theory to analyze the stability of the periodic solutions. Through the analysis of the curves, we can see the influences of the amplitude of excitation and damping on the amplitude-frequency characteristic curves.We also get the approximate solutions applying harmonic balance method and obtain the amplitude-frequency characteristic curves under different parameters. The study indicates that the response amplitude is greater when the exciting force is greater and the damping is smaller. The results of harmonic balance method are agreed well with the numerical solution. The stability of the periodic solutions is investigated by the method of varying amplitudes and phases. |
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