DECIV - Departamento de Engenharia Civil

URI permanente desta comunidadehttp://www.hml.repositorio.ufop.br/handle/123456789/496

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Autor: search.filters.author.Sarmanho, Arlene Maria CunhaData final: 2019

Resultados da Pesquisa

Agora exibindo 1 - 10 de 41
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    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 Almeida
    Neste 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).
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    Experimental analysis of bolts employed as shear connectors in circular concrete-filled tube columns.
    (2019) Xavier, Ellen Martins; Ribeiro Neto, Juliano Geraldo; Sarmanho, Arlene Maria Cunha; Amparo, Lucas Roquete; Paula, Letícia Gualberto Caldeira de
    This paper presents experimental and theoretical analysis of bolts employed as shear connectors in circular concrete-filled steel tube columns (CFTs). The theoretical results, obtained from ABNT NBR 16239:2013 formulations, were compared with the experimental results. A series of push-out tests were carried out, where the diameter and length of the bolts, the number of connectors and the concrete strength were varied. From the experimental results, it was observed that the equations from ABNT NBR 16239:2013 are conservative. Therefore, it is proposed an adjustment to the formulations in order to consider the concrete confinement. It was also verified that increments in the diameter and the length of the bolt increase the load capacity of the connector. However, the variation of the quantity of bolts and the concrete strength did not interfere in the load capacity.
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    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 Braz
    This 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.
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    Effect of fillet welds on T-joints with thin-walled chords.
    (2018) Pereira, Daniel José Rocha; Sarmanho, Arlene Maria Cunha; Nunes, Gabriel Vieira; Guerra, Messias Júnio Lopes; Alves, Vinicius Nicchio
    Tubular joints with thin-walled sections could have a wide range of applications in the construction industry, possibly providing light structures with high structural efficiency. However, current design prescriptions do not recommend their use and more studies are needed to attest their viability. In this context, the effect of the size of fillet welds on cold-formed T-joints consisting of thin-walled rectangular hollow section chords and circular hollow section braces under axial compression loading was analysed. Experimental and numerical analyses were conducted and the results were compared with current design prescriptions. Three experiments were performed, with different weld sizes, in a machine that provided displacement-controlled testing with data acquisition from strain gauges and displacement transducers. Finite-element models were developed to replicate the general experimental setup and the results showed good correlation with the experimental data, indicating that the size of the weld influences joint resistance.
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    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 de
    Este 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.
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    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 Almeida
    This 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.
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    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 e
    This 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.
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    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 de
    Circular 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.
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    Experimental analysis of a mechanical shear connector in concrete filled steel tube column.
    (2017) Ribeiro Neto, Juliano Geraldo; Sarmanho, Arlene Maria Cunha
    Este trabalho compreende um estudo analítico e experimental do comportamento estrutural de conectores de cisalhamento em pilares mistos, formados por perfis tubulares laminados de seção circular de aço preenchido por concreto simples. Para este estudo foi adotado um conector do tipo parafuso estrutural, a fim de verificar a validade das expressões analíticas constantes na ABNT NBR 16239:2014 [1]. Foi realizada uma série de ensaios experimentais de cisalhamento direto, fixando o diâmetro externo do tubo e variando a espessura, o diâmetro do parafuso, a resistência do concreto e a presença ou não de folga no furo. Da análise dos resultados observa-se que é viável a utilização desse tipo de conector, que as equações existentes para o dimensionamento dos mesmos estão a favor da segurança e podem ser ajustadas para fornecer valores de capacidade resistente mais próximo do experimental.
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    Análise numérica de ligações tipo “T” com perfis tubulares de paredes esbeltas.
    (2017) Guerra, Messias Júnio Lopes; Sarmanho, Arlene Maria Cunha; Nunes, Gabriel Vieira; Pereira, Daniel José Rocha; Silva Neto, João Batista da
    Neste trabalho é apresentada uma análise teórica e numérica de ligações soldadas do tipo “T” formadas por perfis tubulares de aço de seções esbeltas, com seção transversal retangular no banzo e circular no montante. Os estudos avaliam o comportamento, os modos de falha e a carga última da ligação. Foi analisada a influência dos parâmetros 2 (razão entre a largura e a espessura do banzo) e  (razão entre o diâmetro do montante e a largura banzo). Os modelos numéricos em elementos finitos e os resultados foram comparados com as prescrições normativas recentes, utilizando o critério de deformação limite para determinação da carga última para o modo de falha de plastificação da parede superior do banzo.