Dimensionamento ótimo de pórticos planos de aço considerando ligações semirrígidas e análise não linear geométrica

Abstract

Competitiveness and the market search for lighter and more economical structures the search for optimized and less costly computing solutions, obtaining the best solution among the countless possible ones. The consideration of the flexibility of the connections together with the nonlinear behavior of steel frames can be used for this purpose without compromising the structural safety. The purpose of this work is to present an optimal design study in relation to the cost of steel frames with semi-rigid connections using Genetics Algorithms and mathematical model of Frye and Morris. A bibliographic review and the theoretical foundation of the concepts of semi-rigid connections and geometric non-linear elastic analysis of reticulated structures (second order analysis) is carried out by the stiffness method, presentation of the standard restrictions in the design of the portal meeting the requirements of the Brazilian standard NBR 8800:2008, concepts and terminologies of Genetic Algorithms, their advantages and disadvantages and comparison in relation to deterministic methods, and mathematical and computational modeling in MATLAB environment using a commercial database of rolled I or H sections and commercial components of beam column connections. At the end, comparative studies are shown with the results obtained by this work with of other similar works found in the literature