Otimização de perfil estrutural quanto ao carregamento de flambagem e frequência natural

Abstract

One of the main objectives of the structural designer is to develop robust and low cost projects. The lack of efficient techniques to optimize structures on the buckling load and natural frequency was the motivation for this project. Due to the high importance and applicability in the context of structural engineering, a plane frame was chosen as the structural model of analysis. The challenge was getting a simple optimal point that simultaneously satisfies the two objective functions, buckling and frequency, which is generally difficult to obtain. In the case of two objective functions, a multiobjective optimization process is necessary. As multiobjective optimization technique, it was adopted the minimax strategy, which gives the best structure for the worst loading condition. Regarding the design variables, it was chosen the thicknesses of the cross section of columns and beams. The results showed that the optimization strategy adopted was satisfactory, because it was possible to determine the thicknesses that resulted in an optimal structure where a criterion is optimized without the detriment of another.