Vibration Characteristics Analysis Of Submerged Ring-stiffened Cylindrical Shells

The ring-stiffened shell have been widely used in many engineering areas; it is interesting and challengeable to study the stactic and dynamic characteristics of ring-stiffened shells. With more and more used in ocean structures, the reseachs have gained more regards. They care the fatigue sound radiation and dynamics response, which base on the free vibration of the ring-stiffened shell.According to Flugge shell theory, the dnamic equations for the ring-stiffened cylindrical shells are given. With both simply supported at the ends, the equation based on the orthotropic theory is given. And the equation of free vibration, which settle for the displacement compatibility condition is presented. Then the differences of two methods is analyzed. It has reviewed that the geometric parameter and properties of ring-stiffers affect on the vibration of cylindrical.The effections of fluid containd static and dynamic pressure. The effections of the flow field are added to the motion equation of ring-stiffened cylindrical. First, the buckling and vibration equations are given, which are used to analyze the effects of static pressure.The expression of the dynaimic water pressure derives by Helmholtz equation, which is application for the finite cylindrical. The equation is just the fluid-structure coupling vibration equation. Then the effections of the pressure on the cylindrical shells vibration in the paper are discussed.