Free Vibration Characteristics Of Ring-stiffened Cylindrical Shell

Ring-stiffened cylindrical shells are widely used in many engineering applications for good mechanical behavior, such as aircraft engines, space vehicles and ocean engineering. Due to the extreme dynamic environment, such as strong aerodynamic action, trenchant temperature environment, fluid-structure interaction, few analytical methods of dynamic characteristics analysis are available for the high-security requirements.The study of vibration frequency must be an essential part of dynamic response problem. In chapter 2 to 4, the vibration characteristics of empty ring-stiffened cylindrical shell, stiffened FG cylindrical shell and fluid-filled ring-stiffened cylindrical shell are presented.Based on Sander’s shell theory and Rayleigh-Ritz method, the shell eigenvalue governing equation is derived. The vibration characteristics are obtained with simply supported ends and clamped-free boundary conditions as the examples. Results are presented on the influence of stiffener, stiffener position and the influence of geometrical dimension. Assume that material properties are graded in the thickness direction of the shell according to the volume fraction power law distribution. On the base of the theoretical study of ring-stiffened cylindrical shell, the shell eigenvalue governing equation is derived, using Rayleigh-Ritz method. Then the natural frequency of the cylindrical shell with clamped-free and simply supported ends boundary conditions is obtained. The influences of constituent volume fraction,constituent materials, stiffener position and the influence of geometrical dimension on natural frequency are presented. Then theoretical formulation is established based on the Love’s shell theory. The shell eigenvalue governing equation is derived with the consideration of fluid-filled property, using wave propagation approach. Then the coupled frequency of the cylindrical shell with different boundary conditions is obtained. The effects of fluid-structure interaction, stiffening parameters, boundary conditions and the influence of geometrical dimension are discussed.