ABSTRACT

Stiffened plates subjected to axial compression loads are very efficient structures, in which a large increment of strength is created by a small addition of weight in the form of stiffeners. During the last two decades extensive experimental investigations for the prediction of ultimate buckling loads have been carried out. A semi-analytical method based on different formulae and codes of practice has been considered for the prediction of the ultimate buckling load of diagonally stiffened plates.

In general the collapse mechanism of stiffened plates subjected to axial compression load presents a complex engineering problem and depends on several geometric variables beside the mechanical properties of the materials used for the plate and the stiffener beside the possibility of different buckling failure modes. The most appropriate formula for the ultimate buckling load and then the mathematical modeling of a multi-criteria optimal design problem of longitudinally stiffened plates subjected to axial compression load without proofs were given in previous papers listed at the references. It is aimed to keep the weight and the costs of the stiffened plate as low as possible and the problem of satisfying a number of conflicting objectives, which lead to a vector optimization problem. In this paper the necessary concepts and definitions for the formulation of the considered multi-criteria optimization problem and its numerical solution will be presented. Finally some examples are given.