Asymmetric buckling of shell-stiffened annular plates

The present study is devoted to some stability problems of annular plates with shell-stiffening. The plate is simply supported, or clamped, or elastic restrains are applied on the boundaries of the plate. Though the load is axisymmetric we shall assume that the deformations are not necessarily axisymmetric. The displacement fields in the plate and the shell are expanded into Fourier series. For the shell all physical quantities are derived from an appropriately chosen Galerkin function. The main goal is to clarify the effect of a stiffening shell on the buckling load. Hence the field equations together with the boundary- and continuity conditions are clarified. These provide the eigenvalue problem from which the critical load can be calculated. In order to solve the eigenvalue problem we have established, appropriate numerical methods are used.