Buckling characteristics of a circular toroidal shell with stiffened ribs

The ring-stiffened toroidal shell is entirely different from the traditional ring-stiffened cylindrical and spherical shells. It has special structurally beneficial characteristics for underwater engineering. A whole welding steel toroidal model with the ring-stiffened ribs has been manufactured, tested until collapse in pressure chamber and analyzed by nonlinear finite element analyses (FEAs). Then the essential cause and collapse mode of this tested ring-stiffened toroidal model have been studied comprehensively by nonlinear FE method. The experimental and numerical results both reveal that the initial geometric imperfection would mainly determine the model׳s final failure mode, critical pressure and collapse deformation. Further parametric study is made to study the buckling property of ring-stiffened toroidal shell, including failure mode and critical pressure loading by varying the structural parameters. This investigation will lay a good foundation for deriving a theoretical solution for the buckling of ring-stiffened toroidal shell in the near future.