Analysis of General Instability and Effective breadth of a Cylindrical Shell Reinforced by Ring Stiffeners under External Hydrostatic Pressure

Abstract

Many studies have been done experimentally and theoretically for the general instability of a cylindrical shell reinforced with ring stiffeners caused by external hydrostatic pressure. In the case of shallow stiffeners, it has been found that the theoretical model has a goodagreement with experimental results for a cylinder simply supported at both ends. However, these theories do not work well for the problem where the ring stiffener become large.An effective breadth of cylindrical shell with the ring stiffener has also been studied by several researchers. However, the equations derived by them for determining the breadth do not have strong theoretical background.In this paper, a reinforced cylindrical shell with ring stiffeners is analyzed based on, the energy method, where local deformation between ring stiffeners is superposed on overall buckling mode as in the same manner as Kendrick's research. As far as the continuity conditions at the junction of the shell plate and ring stiffeners is concerned, displacement compatibility is imposed in the present paper instead of strain continuity conditions employed in the many previous researches. The present method accurately determines the critical pressure not only for shallow but also for deep ring stiffeners. Several problems are solved and compared with experimental results and the solutions by other reseachers. These comparisons show that the proposed method is effective for determing the critical pressure of the reinforced cylindrical shell. The effecive breadth of shell plate is also determined from the results of critical pressure.