Otimização de vigas biapoiadas de concreto armado

Abstract

This paper deals with an optimization model for minimum cost of simply supported concrete beams of rectangular section subjected to a uniformly distributed load. It was considered the amount of concrete, the longitudinal and transverse steel reinforcement and the formwork used in the construction process to calculate the monetary cost of the optimized beam. The constraints of the model were based on the requirements of ABNT NBR 6118/2007 and some principles of easy building practice. The model’s formulation and its computational implementation were carried out in order to enable the practical use of the results. To make it possible, the area of longitudinal reinforcement is given by indicating the diameter, number and arrangement within the section of steel bars .The transverse reinforcement was modeled with common stirrups, being defined by the type of bars indicated on reinforcement and their spacing . The model can easily be calibrated to indicate the dimensions of the concrete section in increments of 1 cm or in multiples of 5 cm which is more commonly used. A Genetic Algorithm was implemented using C + + language on BIOS (Biologically Inspirade Optimization System), a software on developing from Laboratory of Computational Mechanics and Visualization at UFC. The model has been shown to be able to reduce costs on dimensioning when the vertical displacements were disconsidered as shown on this work.