Navegando por Autor "Oliveira, Matheus Miranda de"

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Análise de ligações tipo luva sob compressão.
(2019) Oliveira, Matheus Miranda de; Sarmanho, Arlene Maria Cunha; Amparo, Lucas Roquete; Sarmanho, Arlene Maria Cunha; Amparo, Lucas Roquete; Carvalho, Hermes; Alves, Vinicius Nicchio
A utilização de perfis tubulares de aço na construção metálica é difundida como uma alternativa aos tradicionais perfis abertos e em algumas aplicações é a mais viável. Nesse contexto, tem-se buscado facilitar a execução, montagem e manutenção, bem como reduzir custos e melhorar o design das estruturas. Assim, esse trabalho apresenta estudos sobre um novo tipo de emenda entre perfis tubulares de seção circular aplicado a sistemas treliçados, a ligação tipo luva. A ligação explorando a eficiência quanto a resistência a tração e compressão dos perfis tubulares, bem como seu apelo estético. A ligação luva é composta por dois tubos de seção circular ligados por parafusos passantes a um terceiro tubo interno e também de seção circular e com menor diâmetro. A ligação permite uma harmonia na continuidade do perfil, tornandose uma ligação que induz esteticamente a uma continuidade das barras ligadas na estrutura real. Algumas pesquisas anteriores avaliaram a ligação luva com parafusos passantes e com a furação alinhada e cruzada sob força axial de tração. Neste trabalho avaliou-se o comportamento da ligação luva sob compressão. Foi desenvolvido um modelo numérico em elementos finitos utilizando o programa computacional ANSYS, permitindo a análise numérica com variações de diversas características geométricas da ligação. As análises numéricas/paramétricas propiciaram a identificação dos possíveis modos de falha da ligação, sendo eles: escoamento da seção bruta, flexão nos parafusos, cisalhamento do parafuso e ovalização dos furos. Além disso, pôde-se estudar parâmetros geométricos limites para o dimensionamento e utilização da luva sob compressão. Ao final foi possível propor e avaliar formulações existentes para a determinação da capacidade resistente da ligação atestando sua eficiência e aplicabilidade.
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 Nicchio
This 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.
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 Nicchio
This 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.
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 Nicchio
Structures 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.
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 Nicchio
This 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.
Model-based damage identification of railway bridges using genetic algorithms.
(2020) Alves, Vinicius Nicchio; Oliveira, Matheus Miranda de; Ribeiro, Diogo; Calçada, Rui; Cury, Alexandre Abrahão
The assessment of structural integrity via numerical model updating has been drawing attention in several areas of engineering over the last years. Basically, it consists in an optimization process based on the minimization of the residuals between measured and estimated numerical re- sponses. In such methodologies, several factors influence the success of both localization and quantification of structural damage, such as: the damage features used in the formulation of the objective function, the optimization algorithm and the adopted updating parameters. Many ex- isting studies using these methods are applied to simple structural systems, e.g., beams, frames and trusses. However, few studies applied to large and complex structures are found in the lit- erature. In this context, this work proposes to assess the performance of a genetic algorithm- based approach applied to two case studies. The first case refers to a two-dimensional model of a hypothetical railway bridge, where the efficiency and robustness of five different indicators are assessed considering three damage scenarios. In the second case, a real railway bridge is con- sidered. The results obtained show that the proposed approach is able to detect, locate and quantify multiple damage with several updating parameters and few target responses.
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 Cunha
This 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.
Simulation of the dynamic behavior of a centenary metallic bridge under metro traffic actions based on advanced interaction models.
(2021) Ribeiro, Diogo; Costa, Bruno J. Afonso; Cruz, Luís; Oliveira, Matheus Miranda de; Alves, Vinicius Nicchio; Montenegro, Pedro Aires; Calçada, Rui
The present work focuses on the evaluation of the dynamic behavior of a centenary steel arch bridge, located in Portugal, under light railway tra±c loads. This works aims to assess the dynamic behavior of the bridge subjected to an alternative type of railway vehicle, more speci ̄cally, a typical underground vehicle that is currently in service in the Lisbon Metro. The dynamic response of the system has been evaluated using two distinct methodologies, namely a moving loads model and a vehicle–bridge interaction model. To achieve this goal, ̄nite element (FE) models from both the bridge and the vehicle have been developed and a comprehensive study has been carried to evaluate the in°uence of distinct factors in the dynamic response of the bridge–train system, namely the methodology used to assess the dynamic response, the location of the response reference point in the deck, the train speed and the vehicle con ̄guration (single or double vehicle). Moreover, both the tra±c safety, passenger comfort and pedestrian comfort have also been evaluated using normative criteria based on acceleration responses. The results shown that the normative limits related to tra±c safety and passenger comfort were never exceeded in any condition analyzed in the study. However, the pedestrian comfort was jeopardized when the train speed exceeded 20 km/h.