Optimal design of planar frames based on structural performance criteria

The aim of this study is to present a new approach, nearer to engineer's point of view, for optimizing the structures, in particular for the planar frames. As a means of improving the overall stability of the structure the objective function chosen to be maximized is the eigenvalues of the buckling modes. The optimization process involves two stages: a preliminary design when a prescribed value for the natural fundamental vibration period is the main constraint and a second stage in which the usual stress, displacement, and side constraints are taken into account. The algorithm used for optimization is based on a classical optimality criteria approach. The steps of the algorithm are illustrated by some examples which demonstrate the effectiveness of the proposed procedure in improving design.