Dimensionamento de vigas de concreto armado submetidas a flexão simples utilizando otimização

Abstract

With the advance of Civil Engineering and the increase in market competitiveness it is increasingly necessary that more efficient and cost-effective structural solutions are proposed. However, even today, the conventional design model is still widely used, based on the experience of the designer with previous works, being an efficient model, but not always economical. In this scenery, the objective of this work was the optimized design of reinforced concrete beams to minimize financial costs. The work was divided into four problems, being that in the first problem only the longitudinal reinforcement design was performed, and in the second problem, only the transverse reinforcement design was performed. In the third problem there was the design of both longitudinal and transverse reinforcement, and finally, in the fourth problem, besides the design of the reinforcement, verification of excessive deformation was added. The problems were applied to two cases, Case 1 was a propped beam and Case 2, a biengasted beam. The objective function took into account the costs of concrete, molds and steel, with the goal of minimizing the cost and, as design variables, the base (bw), height (h) of the cross-section and the longitudinal and transverse stell áreas, with safety constraints based on ABNT NBR 6118:2014. Furthemore, the equations inherent to the design of a cross-section subjected to simple bending and the verification of excessive deformation were also employed as constraints. After the analyses, it was possible to verify the efficiency of the optimized design because it offered economical solutions, besides being efficient from the safety point of view.