Global stability and natural frequencies of vibration in multi-objective op- timization of 3D steel frames.

Resumo

In a structural optimization problem, it may be desired not only to minimize the cost of the final design
but also to enhance its performance. In this sense, aspects concerning the first natural frequency of vibration
and the critical load factor concerning global stability may be desired to be maximized. Also, for instance, the
displacements are to be minimized, leading to conflicting objective functions. This paper analyses multi-objective
structural optimization of 3D steel frames considering the weight minimization of the structure with the first natural
frequency, the critical load factor, and the maximum horizontal displacement in three different multi-objective
problems. The analysis presents their Pareto-fronts showing the non-dominated solutions, leaving the task of
defining which solution or solutions to be extracted from these curves to a Multi-Tournament method based on the
preferences of the decision-maker. The search algorithm adopted is the Third Step Differential Evolution (GDE3)
coupled with an Adaptive Penalty (APM) Method to handle the constraints.