Análise do efeito da redistribuição de esforços no dimensionamento de um edifício em concreto armado

Abstract

Structural analysis is one of the most important phases in the design of buildings, since it provides the requesting efforts and deformations in the various structural elements, thus allowing the verification of the ultimate and service limit states provided for in ABNT NBR 6118:2014. This standard establishes five different models to carry it out, among which stand out linear analysis and linear analysis with redistribution of efforts. For the application of the latter, it is necessary that the ductility conditions are met in the sections, which is done by limiting the position of the neutral line and the redistribution coefficient, otherwise, more careful analyzes of the elements are required. This paper presents how the application of redistribution of efforts is carried out in a computational program for structural calculation, Eberick 2022, as well as the effect it has on the design of a reinforced concrete building. From the results obtained in the two studied models, it was verified that the beams present greater positive bending moments, but that this increase did not cause a significant variation in the reinforcement of the sections. The negative moments decay, with a consequent decrease in the number of bars at the supports. It was also found that the redistribution coefficients are not uniform in all analyzed sections and that, in addition to being beneficial for the beam design, the redistribution of efforts reduces the reinforcement of the columns, since smaller moments are transmitted to them. This change in dimensioned reinforcement was also noted in the quantity of materials, which showed significant reductions in the total weight of steel. Finally, it is concluded that it is important to consider the redistribution of efforts in the structural design of a reinforced concrete building, since, in addition to making the computational model and analysis more realistic, it generates a more uniform distribution of bars, avoiding their congestion.