TÍTULO DO TRABALHO AVALIAÇÃO DA ESTABILIDADE GLOBAL EM EDIFÍCIOS DE CONCRETO ARMADO: PARÂMETRO DE INSTABILIDADE α E COEFICIENTE ϒz

Abstract

The construction of increasingly taller structures highlights the importance of studying the global stability of reinforced concrete structures. Therefore, the parameters α and coefficient γ_z allow verifying the need to consider or not the second-order effects in a given structure. In this study, the global stability analysis of a four-story building was performed. The first step consisted of defining the structure to be used in the study. In this case, three situations were proposed for the structure modeling, varying the dimensions and cross-sectional area of the pillars, as well as the concrete's fck to be used. They are as follows: Situation I (Pillar: 14x30 cm; Fck: 30 MPa), Situation II (Pillar: 14x40 cm; Fck: 25 MPa), and Situation III (Pillar: 20x30 cm; Fck: 20 MPa). Next, the action of wind on the structure is determined, allowing the calculation of the parameters α and coefficient γ_z. Finally, a comparative analysis in 2D and 3D of the bending moment and shear force at a specific node of the structure was performed. To carry out the analysis of global effects, the software Ftool and Eberick were used, assisting in the prototyping and structural calculation of buildings in 2D and 3D, respectively. With the calculations performed, it was concluded that the structural design using Situation II presented the best stiffness, while the other situations, I and III, proved to be less efficient. Therefore, it is possible to conclude that prioritizing an increase in the section's inertia rather than the fck of the concrete is more valid.