Dimensionamento Otimizado De Pilares-Parede

Optimized Design of wall columns

Abstract

The overall stability of a tall building is usually guaranteed by bracing structures, such as rectangular or U-shaped pillars. Thus, this article aims to realize the optimized design of wall-pillars from the existing requests and in accordance with the normative prescriptions. The use of optimization for the optimum design of columns has been the object of several studies, such as those of Saves (2005), Rodrigues Júnior (2005), Alves (2013), Bordignon and Kripka (2012), Sias (2014), Alves, Souza and Gama (2017), and Alves e Souza (2018). On the other hand, Souza (2017), Medeiros (2016) and Araújo (2007) deal with the dimensioning of wall-columns. According to NBR 6118: 2014, wall-pillars are those in which the largest cross-sectional dimension exceeds 5 times the smallest. They are classified as simple, in the case of rectangular sections, or composites, in the case of "U" pillars, which have 3 blades, when in at least one of them the thickness is less than 1/5 of the largest dimension. The present work aims to present the formulation of the problem of optimized desing of wall columns, rectangular section and "U" according to NBR 6118: 2014. For the optimization will be used the Interior Points Method, tool available in the library of Matlab software. Two examples will be analyzed, one referring to the rectangular section and another to the "U" section. The optimum design of both will involve two methods, the traditional one and the one of the strip decomposition, in order to compare the optimized steel areas. Then, it is intended to optimize the compressive strength of the concrete (f_ck) of each of the sections in order to verify the savings resulting from this optimization.