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As vigas alveolares são vigas metálicas que possuem aberturas no seu montante da alma. Usualmente, estas vigas são fabricadas a partir de vigas laminadas a quente de secção I, nas quais é feito um corte com um certo padrão ao longo do montante da alma, desta forma são obtidas duas secções Tê e posteriormente estas duas secções são deslocadas e soldadas para formar uma viga alveolar. Investigou-se o comportamento resistente das vigas alveolares pelos métodos de elementos finitos através do software ANSYS. Foi escolhida uma viga de perfil IPE 220 de aço S355 como viga paternal e foram investigadas vigas alveolares de diferentes comprimentos e com diferentes parâmetros geométricos, tais como, a altura final da secção transversal, o diâmetro das aberturas e os espaçamentos entre aberturas, fornecidos pelo catálogo da ArcelorMittal. Foram realizadas um total de 356 simulações, nas quais todas foram realizadas com um carregamento uniformemente distribuído aplicado no banzo superior, a carga foi aumentada de forma incremental até ao momento que a viga sofresse de um colapso. Foram realizadas simulações à temperatura ambiente 20 [°C] e a temperaturas elevadas de 500, 600 e 700 [°C]. No modelo foram implementadas as imperfeições geométricas e materiais de acordo com literaturas. Teve-se como objetivo principal verificar os momentos resistentes à encurvadura lateral torsional e comparar com os resultados obtidos através Eurocódigo 3 parte 1-2 sendo necessário recorrer ao Eurocódigo 3 parte 1-1, também foi feita a comparação entre os resultados numéricos e os resultados obtidos através da proposta de Vila Real. Foram analisados os modos de colapso ocorrentes das vigas alveolares, visto que estas podem sofrer de uma instabilidade global ou local. De forma suplementar fizeram-se simulações de vigas sólidas, estando estas sujeitas às mesmas condições que as das vigas alveolares. Para as vigas alveolares conclui-se que existe divergência entre os resultados obtidos de forma numérica e os resultados obtidos pela norma. Quando os resultados são comparados em relação à sua esbelteza verifica-se uma maior concordância entre os resultados dos momentos resistentes. Notou-se também que o modo de colapso para as vigas mais curtas dá-se pelo mecanismo de Vierendeel sendo que com o aumento do comprimento passamos a verificar a encurvadura lateral torsional. Para as vigas sólidas verifica-se concordância entre os resultados numéricos e os resultados analíticos.
Cellular beams are metal beams that have openings in their web. Usually, these beams are manufactured from hot-rolled I-section members, in which a cut is made with a certain pattern along the web, thus there are two T-sections and later these two sections are moved and welded to form a cellular beam. The resistant behavior of cellular beams was investigated by finite element methods using the ANSYS software. An IPE 220 profile beam made of S355 steel was chosen as the paternal beam and cellular beams of different lengths and with different geometric parameters were investigated, such as the final height of the cross section, the diameter of the web openings and the spacing between openings, provided by ArcelorMittal catalog. A total of 356 simulations were carried out, in which all were executed with a uniform distributed load applied on the upper flange, the load was increased incrementally until the instance the beam suffered a collapse. Simulations were performed at room temperature 20 [° C] and at high temperatures of 500, 600 and 700 [° C]. In the model, geometric and material imperfections were implemented according to literatures. The main goal was to verify the moment of resistance to lateral torsional buckling and to compare with the results obtained through Eurocode 3 part 1-2, being necessary to make use of the Eurocode 3 part 1-1. A comparison was also made between the numerical results and the results obtained through the Vila Real proposal. The occurring failure modes of the cellular beams were analyzed, as they can suffer from global or local failure modes. In addition, simulations of solid beams were made, considering the same conditions in the model as the cellular beams. For cellular beams it is concluded that there is a divergence between the results obtained in numerical form and the results obtained by the Eurocode 3. When the results are compared in relation to their slenderness, there is a greater agreement between the results of the moment of resistance. It was also noted that the failure mode for the shortest beams is due to the Vierendeel mechanism, and with the increase in length, we can verify the lateral torsional buckling. For solid beams, between the numerical and the analytical results there is agreement.
Cellular beams are metal beams that have openings in their web. Usually, these beams are manufactured from hot-rolled I-section members, in which a cut is made with a certain pattern along the web, thus there are two T-sections and later these two sections are moved and welded to form a cellular beam. The resistant behavior of cellular beams was investigated by finite element methods using the ANSYS software. An IPE 220 profile beam made of S355 steel was chosen as the paternal beam and cellular beams of different lengths and with different geometric parameters were investigated, such as the final height of the cross section, the diameter of the web openings and the spacing between openings, provided by ArcelorMittal catalog. A total of 356 simulations were carried out, in which all were executed with a uniform distributed load applied on the upper flange, the load was increased incrementally until the instance the beam suffered a collapse. Simulations were performed at room temperature 20 [° C] and at high temperatures of 500, 600 and 700 [° C]. In the model, geometric and material imperfections were implemented according to literatures. The main goal was to verify the moment of resistance to lateral torsional buckling and to compare with the results obtained through Eurocode 3 part 1-2, being necessary to make use of the Eurocode 3 part 1-1. A comparison was also made between the numerical results and the results obtained through the Vila Real proposal. The occurring failure modes of the cellular beams were analyzed, as they can suffer from global or local failure modes. In addition, simulations of solid beams were made, considering the same conditions in the model as the cellular beams. For cellular beams it is concluded that there is a divergence between the results obtained in numerical form and the results obtained by the Eurocode 3. When the results are compared in relation to their slenderness, there is a greater agreement between the results of the moment of resistance. It was also noted that the failure mode for the shortest beams is due to the Vierendeel mechanism, and with the increase in length, we can verify the lateral torsional buckling. For solid beams, between the numerical and the analytical results there is agreement.
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Vigas alveolares Instabilidade global e locaL Temperaturas elevadas Método dos elementos finitos Eurocódigo 3