Vibration of open circular cylindrical shells with intermediate ring supports

This paper is concerned with the free vibration of open circular cylindrical shells with intermediate ring supports. An analytical procedure for determining the free vibration frequencies of such shells is developed based on the Flu¨gge thin shell theory. An open circular cylindrical shell is assumed to be simply supported along the two straight edges and the remaining two opposite curved edges may have any combinations of support conditions. The shell is divided into multiple segments along the locations of the intermediate ring supports. The state-space technique is employed to derive the exact solutions for each shell segment and the domain decomposition method is applied to enforce the geometric and natural boundary/interface conditions along the interfaces of the shell segments and the curved edges of the shell. Comparison studies are carried out to verify the correctness of the proposed method. Exact vibration frequencies are obtained for open circular cylindrical shells with multiple intermediate ring supports. The influence of the number of intermediate ring supports, the locations of the ring supports, the boundary conditions and the variation of the included angle of the shells on the natural frequencies are examined. The exact vibration solutions can be used as important benchmark values for researchers to check their numerical methods and for engineers to design such shell structures