EM - Escola de Minas
URI permanente desta comunidadehttp://www.hml.repositorio.ufop.br/handle/123456789/6
Notícias
A Escola de Minas de Ouro Preto foi fundada pelo cientista Claude Henri Gorceix e inaugurada em 12 de outubro de 1876.
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9 resultados
Resultados da Pesquisa
Item Experimental and numerical analysis of composite steel and concrete trusses.(2021) Martins, Joel Donizete; Pereira Junior, Sineval Esteves; Xavier, Ellen Martins; Neiva, Luiz Henrique de Almeida; Sarmanho, Arlene Maria CunhaIn the present work, two composite trusses formed by tubular shapes supporting a concrete slab were evaluated. Based on analytical formulation related to the problem, according to recommendations of standards, numerical analyses were performed, with models created using the software Ansys, and an experimental analysis with full-scale tests. Good agreement between the three analysis types was observed. A possible shear connection failure in one truss was observed. With a change in the second truss's connector length, an increase in the structure's strength and rigidity was achieved. In this study, because the shear connectors were directly welded on the upper chord wall, local effects with localized plastifications were evidenced.Item Analysis of beam-to-upright end connections steel storage systems.(2020) Escanio, Lucas Alves; Elias, Guilherme Cássio; Neiva, Luiz Henrique de Almeida; Alves, Vinicius Nicchio; Sarmanho, Arlene Maria CunhaThis study presents an experimental and numerical research into the behavior of beam-to-upright end connections, which are part of steel storage systems. A total of 21 cantilever tests comprising three upright and four beam cross sections, were conducted, and a finite element numerical model was developed. The model was developed to compare its results with experimental results and to extrapolate these results in a parametric analysis. The aim of the study is to evaluate the behavior, semi-rigidity, and influence of the geometric parameters in the stiffness of beam–upright lipped connections of pallet-type industrial storage systems. The results of the numerical model showed good correlation with the experimental results, in terms of moment–rotation behavior and the initial stiffness values, with a maximum differenc e of 10%. In the parametric analysis, a pattern was observed in the variation of stiffness when the dimensions—mainly the height of beams—of the prototypes were increased.Item Análise numérica de ligações tipo T com perfis tubulares.(2019) Guerra, Messias Júnio Lopes; Nunes, Gabriel Vieira; Sarmanho, Arlene Maria Cunha; Pereira, Daniel José Rocha; Neiva, Luiz Henrique de AlmeidaNeste trabalho é apresentada uma análise paramétrica de ligações soldadas do tipo T formadas por perfis estruturais de aço sem costura, com seção transversal retangular no banzo e circular no montante. Um modelo numérico foi calibrado com resultados experimentais e após a calibração foi feito um estudo paramétrico variando os parâmetros (relação entre o diâmetro do montante e largura da face banzo conectado) e 2 (relação entre a largura e a espessura da face do banzo). Os resultados dos modelos numéricos, obtidos pelo critério de deformação limite, foram comparados com as prescrições mais recentes da ABNT NBR 16239 (2013) e da ISO 14346 (2013).Item Numerical and experimental analysis of perforated rack members under compression.(2018) Neiva, Luiz Henrique de Almeida; Sarmanho, Arlene Maria Cunha; Faria, Vinícius de Oliveira; Souza, Flávio Teixeira de; Starlino, Juliane Aparecida BrazThis paper presents a numerical and experimental study of uprights with rack-type perforated section in coldformed profiles, subjected to axial compression. 18 tests were performed on uprights with fixed-ends under uniform compression load to obtain the ultimate load applied, along with the measurement of the displacements. A numerical model with material and geometric nonlinearities was calibrated with the experimental tests. Next, a parametric analysis with 64 different numerical models was performed, determining the ultimate loads of the models. These results, when compared to the DSM predictions, showed that the equations of DSM are unreliable to predict the strength of this type of perforated uprights. Therefore, based on the model results, modifications were proposed to the parameters of the DSM distortional mode curve, so that it can predict the strength of the models studied.Item Análise do modo distorcional de elementos perfurados segundo método da resistência direta.(2018) Neiva, Luiz Henrique de Almeida; Sales, Amaury Eloy Carvalho Araújo; Elias, Guilherme Cássio; Sarmanho, Arlene Maria Cunha; Souza, Flávio Teixeira deEste trabalho apresenta um estudo teórico e numérico da influência de perfurações no comportamento e capacidade resistente de pilares em perfis formados a frio submetidos a compressão. Pilares com diferentes seções transversais e perfurações foram avaliados numericamente via ANSYS e GBTul, com ênfase no modo de instabilidade distorcional. As forças últimas da análise numérica foram comparadas às equações do Método da Resistência Direta (MRD) da ABNT NBR 14762:2010. Finalmente, foram propostas adequações às equações do MRD para possibilitar o dimensionamento de pilares que apresentam seções com a tipologia de perfurações estudadas.Item Cold formed steel semi rigid joints.(2018) Silva, Adriano Toledo da; Sarmanho, Arlene Maria Cunha; Nunes, Gabriel Vieira; Pereira, Daniel José Rocha; Neiva, Luiz Henrique de AlmeidaThis article presents a theoretical and numerical study of an innovative joint using cold-formed steel sections. The motivation for the study of this connection is the ease of manufacturing and assembly that it provides. The profiles are made of coldformed lipped channel sections, which are welded to form closed built-up sections on the columns and open built-up lipped sections to the beams. The beams use endplates connected by bolts (threaded bars) to the columns. The study evaluates the connection’s initial stiffness of 19 models, where the following parameters were varied: the thickness of the profiles and endplates, the height of the column sections and the diameter of the bolts. A theoretical and a numerical study were developed: the numerical study was performed using finite elements through the commercial software ANSYS, whereas the theoretical study was made based on the component method, prescribed by Eurocode 3, that does not include the design of the connection analyzed herein. Thus, aiming to enable the design of joints composed of cold-formed lipped channel sections, the analysis results were compared and an adjustment coefficient, proportional to the slenderness of the column’s plates, was proposed. The coefficient was introduced to the stiffness component that represents the column web in compression in the mechanical model. The ratio between the coefficients’ numerical and theoretical values presented a maximum variation of 11%, which was considered satisfactory.Item Ultimate load of steel storage systems uprights.(2018) Elias, Guilherme Cássio; Neiva, Luiz Henrique de Almeida; Sarmanho, Arlene Maria Cunha; Alves, Vinicius Nicchio; Castro, Ana Flávia Barbosa eThis study presents an experimental investigation into the behavior of steel storage rack perforated uprights under axial compression. A total of 44 prototypes comprising eleven cross-sections and four lengths were tested, and a buckling curve of the studied uprights is proposed. The focus of the study is to compare the ultimate loads of the experimental uprights by numerical and theoretical analysis, through modifications to the direct strength method (DSM) equations, using the Brazilian and European design codes. The theoretical values obtained are smaller than the experimental ones, and the interaction of distortional and global buckling is also discussed. The ultimate loads obtained with the proposed buckling curve were less conservative than the DSM equations.Item Análise da influência da variação de perfurações no comportamento e capacidade de carga de perfis formados a frio de seção tipo rack.(2017) Neiva, Luiz Henrique de Almeida; Sarmanho, Arlene Maria Cunha; Sarmanho, Arlene Maria Cunha; Souza, Flávio Teixeira de; Lima, Luciano Rodrigues Ornelas deOs perfis formados a frio (PFF), em função de sua versatilidade, economia e leveza, tem cada vez mais sido utilizados na construção metálica. A trabalhabilidade encontrada nos perfis de paredes finas permite uma grande variedade de seções transversais e aplicações. Um desses usos se dá nos sistemas de armazenagem, os racks, nos quais os PFF são empregados na maioria dos elementos, inclusive nas colunas. Tais colunas apresentam perfurações ao longo do comprimento, visando facilitar a montagem do sistema como um todo. Estudos a respeito da influência dessas perfurações no comportamento e resistência das colunas são relativamente recentes. Portanto, é necessário avaliar os modos de instabilidade usuais em seções de PFF com perfurações e a carga máxima dos elementos. Além disso, dificilmente o carregamento nas colunas do tipo rack é de forma centrada, considerando o arranjo dos sistemas de armazenagem. O carregamento excêntrico afeta a capacidade máxima, bem como o modo de falha dos perfis formados a frio. O objetivo deste trabalho é contribuir para o entendimento da influência das perfurações e da excentricidade nas colunas, bem como avaliar a ocorrência de modos de flambagem, local e distorcional, considerando o carregamento centrado e excêntrico. Os estudos foram realizados por meio do Método dos Elementos Finitos, com a utilização do programa ANSYS. Foi realizado estudo considerando perfurações ao longo do comprimento das colunas, sendo avaliada a influência do tamanho e da inclinação dos furos, bem como a variação da largura da alma, na carga de flambagem e na carga máxima desse elemento. No estudo citado foi considerada a coluna com carregamento centrado e com os resultados foi avaliada a influência da excentricidade para o arranjo de furos inclinados. Ao final é proposta uma formulação para avaliação da capacidade resistente para o modo local e distorcional utilizando o Método da Resistência Direta que é previsto em diversas prescrições normativas.Item Numerical analysis of truss systems with stiffened flattened end-bars.(2018) Mazon, Ana Amélia Oliveira; Sarmanho, Arlene Maria Cunha; Nunes, Gabriel Vieira; Amparo, Lucas Roquete; Neiva, Luiz Henrique de Almeida; Souza, Flávio Teixeira deCircular hollow sections are usually used in long-span roof truss systems. One of the typology for connecting elements in such structures involves the flattening of bar ends. This article presents the numerical analysis of a plane truss composed of circular hollow sections, in which diagonal bars have flattened ends. In this sense, a new flattening typology called stiffened flattening is proposed, characterized by a non-flat geometry, with the creation of stiffeners in the lateral edges of the diagonal flattened ends. The diagonal connecting system with the chord members uses connecting plates. The plates are welded to the chords and the diagonals are connected to latter through a single bolt. The numerical analysis using finite elements method was developed in two stages through ANSYS software with the Parametric Design Language (APDL), in which parameters such as geometry, materials, element types, boundary conditions and loads are specified. A non-linear analysis was performed using shell elements on the chords, diagonals, plates and welds, and contact elements between the diagonals with stiffened flattened ends and the connecting plates. Initially, a numerical study of the connecting node and the stiffened flattened end was performed, and the results directed the modeling of the plane truss. The numerical results were calibrated with the experimental truss results in full scale. The numerical result of the plane truss was also compared to a theoretical study, considering the axial load eccentricity applied in the diagonal with stiffened flattened ends. The study was based on the consideration of combined effects of axial force and bending moment provided by the Brazilian standard ABNT NBR 8800:2008. The final results indicate that the numerical model proposed is efficient and has good correlation with the experimental and theoretical results.