Otimização geométrica da seção de terças de cobertura em perfis formados a frio

Abstract

It is known that cold-formed profiles have been gaining ground among steel structures due to their characteristics such as a good strength/weight ratio, for example. However, there are few variations in the cross-sections of these profiles in a commercial context, which often results in oversized projects. Thus, this work focuses primarily on the geometric optimization of steel purlins in cold-formed profiles using manufacturing restrictions, in order to contribute to generating savings in both raw materials and money for projects that contain this element, thus impacting the economic and environmental scope, and preserving the applicability of this study since manufacturable sections are considered. To make this possible, a routine for calculating the sizing of cold-formed profiles subjected to simple bending demands was developed using the Python programming language. The Effective Width Method, which is included in ABNT NBR 14762:2010, is used as the dimensioning method. For this purpose, the cross-sections of the profiles were discretized into nodes and elements, so that profiles of any cross-section determined by the problem could be dimensioned. After developing the routine, the Simulated Annealing optimization method was implemented, which made it possible to find which cross-sectional shape of the profiles meets the requirements with the lowest material consumption, thus finding the optimal cross-sections of the same according to the length, and thus finding optimal dimensional relations and a convergence pattern of the geometric shape of the optimized profiles. Finally, geometric sections were also analyzed without considering manufacturing restrictions, where it was possible to observe the behavior of the geometry of the profiles converging to circular sections as being the optimal ones.