Estudo de metodologias para o dimensionamento de vigas mistas de aço e concreto com perfil celular

Abstract

Resumo Atualmente, com o avanço da tecnologia de corte e solda, perfis de aço com aberturas sequenciais na forma circular, denominados perfis celulares, vêm sendo bastante utilizadas como vigas de edificações. A ABNT NBR 8800:2008 e as normas estrangeiras não abordam vigas de aço e vigas mistas de aço e concreto com perfil celular, o que contribui para que o seu uso seja limitado. Foi desenvolvido e aferido um programa computacional para o dimensionamento de vigas mistas de aço e concreto com perfil celular biapoiadas de acordo com duas metodologias distintas da literatura. Um estudo paramétrico abordando vigas mistas com perfis celulares obtidos de dois perfis I de aço laminados comerciais foi realizado. Nesse estudo, a influência dos parâmetros geométricos do perfil celular e do comprimento do vão da viga na resistência e na forma de colapso foi analisada. Foi possível concluir que em muitas situações o uso de vigas mistas com perfil celular é vantajoso em relação às vigas mistas de alma cheia.

Numerical simulation of composite steel-concrete alveolar beams: web-post buckling, Vierendeel and flexural mechanisms

“…Thus, with practically the same self-weight, the expanded profiles are produced with a greater moment of inertia and, consequently, greater flexural strength, resulting in a better performance under serviceability limit states. According to Badke-Neto et al (2015), depending on the shape of the openings, the alveolar beams can be named as castellated beams (with hexagonal openings) or cellular beams (with circular openings). Furthermore, the use of steel alveolar beams presents other advantages, in addition to the structural ones, such as an appealing aesthetic aspect and the possibility of passing pipes through the openings, which allows the optimization of the ceiling height in buildings.…”

“…Furthermore, the use of steel alveolar beams presents other advantages, in addition to the structural ones, such as an appealing aesthetic aspect and the possibility of passing pipes through the openings, which allows the optimization of the ceiling height in buildings. However, in terms of structural behavior, these beams also present some disadvantages, such as the reduction in shear resistance and a worse performance when subjected to concentrated loads, in comparison to full web beams, often requiring reinforcements on the web, thus increasing their cost (Badke-Neto et al, 2015). Moreover, due to their peculiar geometry, specific modes of failure may occur and must be properly understood for their correct employment as reliable structural elements.…”

Predicted temperature development on protected cellular steel beam (CSB) under fire exposure

“…The standard I or H steel beam was trimmed into semi-circular shape along the web section. After the cutting process ended, then the two halves were separated and welded together to form a new, stronger and stiffer section called CSB with increase depth of the web section (Badke-Neto et al, 2015). The web section depth is much longer than the standard steel beam, which leads to larger section modulus.…”

“…The production process of the CSB is shown in Figure 1. It is virtually using the same amount of steel when adopting CSB as per original steel beam section (Badke-Neto et al, 2015). This type of beam creates much higher moment strength due to the increased height of the cross-section, which can accommodate longer spans (Badke-Neto et al, 2015).…”

“…It is virtually using the same amount of steel when adopting CSB as per original steel beam section (Badke-Neto et al, 2015). This type of beam creates much higher moment strength due to the increased height of the cross-section, which can accommodate longer spans (Badke-Neto et al, 2015). Apart from that, composite CSB systems have significantly reduced the material cost of fabricating CSB, improve strength and ability to improvise the beam design.…”