DECIV - Artigos publicados em periódicos
URI permanente para esta coleçãohttp://www.hml.repositorio.ufop.br/handle/123456789/497
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Item Design of sleeve connections with cross-bolted on circular hollow sections under axial tension.(2022) Amparo, Lucas Roquete; Oliveira, Matheus Miranda de; Sarmanho, Arlene Maria Cunha; Xavier, Ellen Martins; Alves, Vinicius NicchioThis present paper evaluates the behavior and resistance capacity of cross-bolted sleeve connections with circular hollow sections (CHS) under axial tension. This connection allows harmony in the continuity of the tubes. The cross-bolted sleeve connection with CHS comprises outer tubes connected by an inner tube and cross bolts at 90◦. Therefore, an experimental, numerical, and parametric study was conducted to identify the connection’s possible failure modes. The experimental tests were developed with cross bolts at 90◦, which enable the identification of fracture through the effective net area, bearing failure, and bolt bending. Finite element (FE) numerical models were developed and validated by Ansys software to provide a parametric study. Thus, such a parametric study was carried out using the verified FE models. The failure modes were evaluated considering the effects of geometric properties concerning their type and location; a relative slenderness limit for the design of connections was proposed, directing the occurrence of a failure in the outer tube. Normative prescriptions do not foresee the design of the sleeve. Therefore, new formulation methods for estimating the strength were proposed, allowing the design of these connections.Item Effect of chord length on CHS-RHS T-joints with slender sections.(2021) Pereira, Daniel José Rocha; Guerra, Messias Júnio Lopes; Sarmanho, Arlene Maria Cunha; Silva Neto, João Batista da; Nunes, Gabriel Vieira; Alves, Vinicius NicchioThe chord length is an essential geometric property that must be defined in the analysis of isolated joints composed of hollow steel sections, as well as the boundary conditions of the test. The analysis of these parameters’ effect on the behavior of joints has been addressed by other studies, mostly with joints between circular hollow sec- tions with compact or semi-compact cross-sections. Recent research about tubular joints has addressed cases with slender sections, where the design of joints containing these sections is still in development. In this context, this study aimed to evaluate the effect of the chord length in the behavior of T-joints between circular hollow section braces and slender rectangular hollow section chords through experimental tests and a numerical study considering the application of axial compression at the braces. The joint behavior was examined through the load-strain and load-deformation curves and the von Mises stress distribution, which allowed the failure mode's determination and the joint resistance value. Chord face failure was observed in the prototypes. It was concluded that a minimum chord length of 0.6m would be the adequate value for the study of the T-joints containing the geometric properties used in this study, which would be equivalent to a chord length five times higher than the width of the cross- section (5b0).Item Behavior and design formulation of steel CHS with sleeve connections.(2021) Amparo, Lucas Roquete; Oliveira, Matheus Miranda de; Sarmanho, Arlene Maria Cunha; Xavier, Ellen Martins; Alves, Vinicius NicchioStructures with tubular profiles gain space in civil construction due to their excellent response under tension, compression, and torsion. They are widely used in structural trusses, especially in large lengths. The profiles have a limited size due to the manufacturing and transport process. Therefore, there is a need to use some mechanism to perform the joint of profiles and obtain the desired length. This work aims to develop a new type of bar splice in circular hollow section (CHS) connection called sleeve connection, composed of two tubes connected with another smaller diameter tube with bolts arranged in a line (staggered bolts). This research presents an experimental, numerical, and parametric study of sleeve connection in CHS under centric axial tension. A numerical model was developed using the finite element method (FEM) considering sleeve connection with staggered bolts. From the numerical results, it was possible to analyze the connection behavior and failure modes: yielding gross cross-section, fracture through the effective net area, bolt shear failure, bearing failure of the plate, and bolt bending failure. This way, formulations were proposed to predict the sleeve connections' behavior with staggered bolts as a function of the failure modes.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.