Constructive symmetry in the stability problem for a cylindrical shell reinforced by stiffening rings under hydrostatic pressure

We use the solution of the problem under study which was earlier obtained by the author 1—3] and which is based on a decomposition of the reinforced shell into separate constructive elements (the ribs and the shell itself) and then on deriving the equilibrium equations and consistency conditions for their strains. Under the assumption that the shell precritical state is momentless, this is a sufficiently exact solution. Its drawback is the significant complexity of the computational algorithm. In the present paper, we show that the laboriousness of the algorithm can be reduced dramatically if the shell under study has elements of design symmetry (identical ribs, their uniform spacing, or both). In addition, we present dependencies determining the stiffening rib rigidity needed to ensure that the shell remains stable for a given critical value of the external hydrostatic pressure.