Single and multi-objective optimization of spatial steel frame considering different bracing systems.

摘要: In a structural optimization problem, the objective may consist in minimizing its cost and maximizing its performance according to horizontal displacements, dynamic behavior, structural stability, etc. In addition to that, finding the best bracing system configuration which presents the best results according to the objectives of the problem is not a trivial task. This work is based on multi-objective optimization of steel frames considering different bracing systems, in which distinct configurations of space frames compete in the same evolutionary process. An integer index variable defines which type of bracing system configuration is adopted for each candidate solution. The output of a multi-objective problem is a Pareto-front curve, from where the designer must choose the most suitable solution according to objectives that are taken into account. A Multi-Tournament method based on the preferences of the decision-maker is used to extract the solutions. The search algorithm adopted is the Third Step Differential Evolution (GDE3) coupled with an Adaptive Penalty (APM) Method to handle the constraints.