Effects of Shell-stiffening on the Stability of Circular Plates

The present paper deals with the stability problem of a thin circular thin plate which is stiffened by a thin cylindrical shell on the external boundary or inside the plate. Assuming axisymmetric deformations and an axisymmetric in-plane load we determine the critical value of the load in order to clarify what is the effect of the stiffening shell. Using Kirchhoff's theory of thin shells and plates the paper presents the governing equations both for the circular plate and for the cylindrical shell, the boundary-and continuity conditions and last but not least numerical results as well.