DECIV - Artigos publicados em periódicos
URI permanente para esta coleçãohttp://www.hml.repositorio.ufop.br/handle/123456789/497
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Item Influence of inverted-v-braced system on the stability and strength of multi-story steel frames.(2023) Azevedo, Iara Santana de; Silva, Andréa Regina Dias da; Silveira, Ricardo Azoubel da MotaPopulation growth in urban centers, together with the lack of physical space, has led to the construction of increasingly tall and slender buildings. Multiple-story structures present substantial challenges to civil engineering because they have specific requirements for their design, construction, and use. The increased number of floors leads to more lateral displacements resulting from horizontal actions. Under these conditions, to ensure system stability, structural bracing components are commonly adopted. In addition, along with the use of more resistant materials and new construction techniques, it is necessary to improve the methodologies adopted in the structural analysis to offer professionals in the area the conditions to undertake safer and more economical projects with better speed and efficiency. Thus, in this study, numerical analyses were applied to steel planar reticulated structures to evaluate their stability and strength when inserting bracing systems. The study compared the arrangement of the bars and analyzed the influence of the parameters of the bracing systems, such as the properties of the cross-section and the position of the inverted-V-braced system. The MASTAN2 program was used to perform nonlinear static assessments using reticulated finite elements that considered both geometrical and physical nonlinearities. It was observed that the inverted-V-braced system had a substantial impact on all of the structures that were analyzed, providing increased stiffness and, as a result, significantly reducing the frame’s lateral displacement.Item Numerical and theoretical investigation of bolted sleeve connections with rectangular hollow sections.(2023) Oliveira, Matheus Miranda de; Amparo, Lucas Roquete; Tanus, Lucas da Silva; Monteiro, Isabella Estevão; Alves, Vinicius Nicchio; Sarmanho, Arlene Maria CunhaThis article presents a theoretical and numerical study of bolted sleeve connections with rectangular hollow sections (RHS) under axial tension and compression. The geometric form of a hollow section provides resistance for high axial loads, torsion and combines effects, spreading its utilization in truss systems. In this context, the sleeve connections proposed explore these characteristics of RHS and offer an attractive aesthetic appearance for the continuity of elements. The bolted sleeve connection with RHS is formed by two outer tubes connected by an inner tube and staggered bolts. Herein, a parametric study was developed for identification of the failure modes in the connection. Finite element models with different geometric parameters and number of bolts were created in commercial software. The width, depth and thickness of RHS tubes and diameter of bolts were variated. In the theoretical/numerical/ parametric results, the yielding gross section failure, the fracture through the effective net area failure and the bearing failure were observed. These failure modes occurred in both outer and inner tubes. The load results were compared to determine the resistance capacity of sleeve connections. The theoretical formulations were evaluated for representation of the ultimate load of the failure modes.Item Bearing failure in bolted sleeve connections with circular hollow sections under compression.(2020) Oliveira, Matheus Miranda de; Amparo, Lucas Roquete; Sarmanho, Arlene Maria Cunha; Pereira, Daniel José Rocha; Alves, Vinicius NicchioThis article analyzes sleeve connections between circular hollow sections. This type of connection is composed of two tubes connected by bolts to an inner tube with a smaller diameter, and explores the efficiency, aesthetics and resistance of hollow sections subjected to tension and compression. In previous researches, sleeve connec- tions with aligned and crossed bolt dispositions and under axial tension were studied. Herein, the behavior of sleeve connections with aligned bolts and under compression was analyzed. A model to represent the connection using the finite element method was developed, which allowed a numerical analysis with geometric property varia- tions. In the numerical/parametric results, bearing failure was observed in all cases, either in the outer or inner tube. Limiting the number of bolts to 6 and considering that connections have a lower outer thickness than the inner tube, a formulation was proposed to determine the ultimate bearing capacity of sleeve connections under com- pression and with bearing failure.Item Experimental and numerical assessment of CHS-RHS T-joints with chords subjected to axial tensile forces.(2021) Silva Neto, João Batista da; Nunes, Gabriel Vieira; Sarmanho, Arlene Maria Cunha; Pereira, Daniel José Rocha; Guerra, Messias Júnio Lopes; Alves, Vinicius NicchioHollow steel sections are widely used in the construction industry due to their mechanical properties. Joints used in these structures are the subject of research because of their singular and critical behavior. Joints containing chords with more slender cross-sections and axially loaded are still a challenge for design, especially in joints with circular hollow sections (CHS) in the braces and rectangular hollow sections (RHS) in the chords. In this context, this work aimed to study joints formed by a combination of CHS braces subjected to compression loads and RHS chords axially loaded with tension, welded as T-joints. Experimental tests, a numerical model using finite elements, and a parametric analysis were developed. A new equation for the chord stress function was proposed, including joints containing chords with semi-compact sections in tension. The joint resistance values obtained through the numerical models were compared with the equations from ISO 14346:2013 and with the proposed equation. It was observed that, for the numerical models with geometric properties inside the normative validity ranges of ISO 14346:2013, the mean rate of analytical by numerical joint resistance results was equal to 68%, using either the normative or the proposed equation. In the same way, for models outside the current validity ranges, either the proposed equation or the modified equation from ISO 14346:2013 could be used to design CHS-RHS T-joints with the geometric and material properties analyzed.Item Bearing failure in bolted sleeve connections with circular hollow sections under compression.(2020) Oliveira, Matheus Miranda de; Amparo, Lucas Roquete; Sarmanho, Arlene Maria Cunha; Pereira, Daniel José Rocha; Alves, Vinicius NicchioThis article analyzes sleeve connections between circular hollow sections. This type of connection is composed of two tubes connected by bolts to an inner tube with a smaller diameter, and explores the efficiency, aesthetics and resistance of hollow sections subjected to tension and compression. In previous researches, sleeve connections with aligned and crossed bolt dispositions and under axial tension were studied. Herein, the behavior of sleeve connections with aligned bolts and under compression was analyzed. A model to represent the connection using the finite element method was developed, which allowed a numerical analysis with geometric property variations. In the numerical/parametric results, bearing failure was observed in all cases, either in the outer or inner tube. Limiting the number of bolts to 6 and considering that connections have a lower outer thickness than the inner tube, a formulation was proposed to determine the ultimate bearing capacity of sleeve connections under compression and with bearing failure.Item Análise estrutural de contêineres marítimos utilizados na construção civil.(2021) Souza, Flávio Teixeira de; França Junior, Adelmo Magalhães de; Sarmanho, Arlene Maria CunhaUma possibilidade para a redução do déficit habitacional ou para a construção de habitações provisórias pode ser a utilização de contêineres marítimos descartados ao fim de sua vida útil na cadeia logística. Pela sua finalidade, os contêineres são estruturas robustas. No entanto, a arquitetura geralmente requer a inclusão de aberturas, a modificação das condições de apoio e o empilhamento dos contêineres, levando a condições de serviço diferentes das originalmente previstas. Este trabalho visa avaliar a influência destas modificações no comportamento estrutural dos contêineres. Para isto foi feita uma análise numérica via Método dos Elementos Finitos no programa comercial SAP2000, considerando aberturas e variações nas condições de apoio sob carregamento oriundo do empilhamento. Os resultados numéricos foram comparados a prescrições de normas brasileiras, e indicaram a viabilidade da utilização dos contêineres na construção civil na maioria das situações. No entanto, a combinação de grandes aberturas e modificações de suas condições de apoio leva a grandes deslocamentos e a elevadas concentrações de tensões, indicando a necessidade da adoção de medidas complementares para assegurar seu bom funcionamento estrutural.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 Numerical and experimental analysis of yield loads in welded gap hollow YT-joint.(2009) Vieira, Rosilene de Fátima; Requena, João Alberto Venegas; Sarmanho, Arlene Maria Cunha; Arcaro, Vinicius FernandoThis paper presents an analytical, experimental, and numerical analysis of plain steel, circular hollow sections welded into a YT joint. The overall behavior and failure of the joint are characterized under axial compression of the lap brace. There are two joint failure modes: plastic failure of the chord face and local buckling of the chord walls. Numerical finite element models agree with the experimental data, in terms of principal stress near the joint intersection, with an accuracy of around 10%. The finite element model thus proves to be reliable and accurate, and will be used in future parametric studies.