| Thin shell structures are widely used in engineering, such as disk-drum sets and sealing teeth structures for thin cylindrical shell components, and which are using in turbine engines and other rotating machinery in actual service process. Thin cylindrical shell can be simplified as a stationary cylindrical shell model under non-working conditions, but which can be simplified as a rotating one for analysis and research under working conditions. Because of the bad working conditions, such as boundary conditions, the high-speed rotation and external complex load conditions, thin-wall cylindrical shell’s vibration behaviors are very complex, and which are easy to produce resonance and instability phenomena, even can lead to a significant fatigue damage failure when the rotating speed are lower than the design speed conditions and affect the machine’s efficiency and operational reliability, so as to cause the destruction of the equipments and scraps. As a result, mechanism research of vibration characteristics of static and rotating thin cylindrical shell with sealing teeth structure is one of the important topics in fields of theory and engineering technology currently, and which also has important theoretical and application values.In this paper, based on a static and rotating thin cylindrical shell component, the integrated using of theoretical methods, numerical simulation calculation and vibration experimental methods, and the inherent characteristics and the response behaviors of static and a rotating thin cylindrical shell under different boundary conditions are analyzed, so analytical methods, numerical method and experimental method can be obtained. At the same time, the vibration characteristics of thin cylindrical shell with sealing teeth are considered, and the influences to thin cylindrical shell. The works finished in this paper are as follows:(1) The transfer matrix method is presented to study the vibration of thin cylindrical shell based on the Love’s shell theory, especially considering vibration characteristics, and the considered boundary conditions are three sets:simply supported-simply supported, clamped-clamped, and clamped-free, and the comparative study has been carried out through the literature and analytic method. The validation is verified through experimental method and finite element simulation under cantilever static state for thin cylindrical shell. At the same time, the natural characteristics of thin cylindrical shell with sealing teeth and the influence law of sealing teeth to thin cylindrical shell are analyzed through the transfer matrix method, then the results are confirmed through finite element method, and modal characteristics of thin cylindrical shell are also studied through experimental method.(2) In view of rotating thin cylindrical shell, the dynamic equilibrium equations are deduced by Hamilton variational principle. The effects on coriolis and centrifugal force are considered. The transfer matrix method is presented to study the vibration of the rotating cylindrical shell under simply supported-simply supported, clamped-clamped, and clamped-free boundary conditions, then analytic method and finite element method are used to analyse the modal characteristics for comparison and confirmation. Finally, the natural characteristics of rotating thin cylindrical shell with sealing teeth and the influence law of sealing teeth to it are analyzed through the transfer matrix method, and the traveling characteristics of rotating thin cylindrical shell with teeth are confirmed through finite element method.(3) An analysis is made to study on response characteristics of a static thin cylindrical shell for forced vibration under a radial harmonic excitation force and impact excitation, and the modal numbers are considered for simply supported-simply supported, clamped-clamped and clamp-free boundary conditions. Through modal superposition method, the Duhamel integral and Simpson numerical calculation methods, and the vibration response results are got under three boundary conditions. Through the response testing system and finite element method, the resonance response behaviors are studied under clamped-free boundary condition. Finally, the response characteristics of the static thin cylindrical shell with sealing teeth and its influence to thin cylindrical shell are obtained by finite element method, and experience is conducted for sealing teeth to study its vibration behaviors.(4) Under simply supported-simply supported, clamped-clamped and clamp-free boundary conditions, the response characteristics for rotating thin cylindrical shell are analyzed under a single point harmonic excitation force. Considering the orthogonality of the modal function, two independent second-order differential equations are got, and the vibration response characteristics of the rotating thin cylindrical shell and resonance frequency expressions are acquired using analysis method. Then, through finite element method, the vibration response characteristics have been carried out to confirm the response characteristics and correctness of analytical method. Finially, vibration response characteristics for thin cylindrical shell with sealing teeth are researched through finite element method under clamped-free boundary condition when it is under single-point excitation force, and sealing teeth’s effect on it.Based on the methods of theoretical analysis, numerical simulation and experimental method, as to thin cylindrical shell, the dynamics mechanism of static and rotating thin cylindrical shell and vibration characteristics are investigated. Vibration characteristics are obtained for thin cylindrical shell with sealing teeth and the effects on smooth thin cylindrical shell, all of which have great engineering application values for vibrations prediction, evaluation and control for thin cylindrical shell. |
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