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The post-buckling path for a cylindrical shell under compressive radial pressure is unstable. The effect of modification of the post-buckling behaviour is in most cases obtained by changing sizing variables, which are usually dimensions of the design element. In this article an alternative concept is applied, namely stabilization of the post-buckling path for a simply supported cylindrical shell under radial compressive pressure is obtained by application of additional loadings acting on the structure without changing the shape or sizes of the optimized element. These loadings can be either active forces applied to the structure or passive ones (reactions of the additional supports) or both active and passive forces acting simultaneously. All three types of stabilizing forces were investigated. Calculations were performed using the ANSYS 11.0 Academic Research code for elastic and elastic-plastic deformations of shells of different length and thickness. [ABSTRACT FROM AUTHOR]

In this article, the problem of the optimal design of simply supported columns under loadings controlled by displacements is investigated. It seeks a cross-sectional area, varying along the axis of the column, which leads to the maximal axial displacement caused by compression before the structure buckles. The uni-modal and bi-modal problems are considered. The optimal solutions for different constraints of minimal and maximal cross-sectional area and various elastic foundations are presented in this article. The results are obtained by solving an analytical formulation of the optimization problem and by using numerical optimization methods, namely the method of moving asymptotes and the simulated annealing method. [ABSTRACT FROM AUTHOR]

The present article is devoted to optimization of shells with a double positive curvature against buckling under overall bending moment which varies along an axis of the shell and under an appropriate shearing force which is associated with that variable bending moment. It seeks the shape of the meridian (only the axially symmetrical shape of the middle surface is allowed for here) as well as the thickness of the shell, which ensure the minimal volume of material. As equality constraints the critical value of the loading parameter and the capacity of a shell are considered. The hypothesis of the locality of buckling is utilized and the optimal structure is sought in the class of shells of uniform stability applying the Shirshov local stability condition. [ABSTRACT FROM AUTHOR]