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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Vibration and Flexural Strength Characteristics of Composite Castellated Beams

Jackson, Rahsean LaNaul 27 February 2002 (has links)
With the development of lightweight concrete and design optimizations, floor vibration problems are becoming a serious serviceability problem. The castellated beam is a prime example and was the focus of this study. The vibration and flexural strength performance were verified in this paper. The vibration characteristics of castellated beams were examined using experimental and analytical test methods. The effective moment of inertia is essential to accurately predict the frequency and deflection of a floor system due to human occupancy. Since castellated beams have non-prismatic cross-sections, their effective moment of inertia is an uncertainty and was verified in this study. This paper confirmed the accuracy of the AISC Design Guide procedures used in for prismatic beam, when applied to castellated beams. The flexural strength of various composite castellated beam were studied. Three full-scale specimens were tested to failure to evaluate their yield and maximum applied load. Each specimen's moment strength was verified based on span, beam properties, concrete slab, and amount of shear connection. / Master of Science
2

Blast resistant design for roof systems

McClendon, Mark Andrew. January 2007 (has links)
Thesis (M.S.)--University of Missouri-Columbia, 2007. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on April 1, 2008) Includes bibliographical references.
3

Stability of Castellated Beams During Erection

Bradley, T. Patrick 05 February 2003 (has links)
The increased depth of castellated beams presents stability problems, specifically during erection. During erection the castellated beam must support the weight of an erector and self-weight until the continuous bracing of the floor deck is in place. The stability of the unbraced member is based on its resistance to lateral-torsional buckling. The cross-sectional properties that are related to lateral-torsional buckling, such as out-of-plane bending, warping constant, and torsional constant were calculated using three different approaches to model the unique geometry of castellated beams. These properties were used in various lateral-torsional buckling solutions to determine which procedure should be used to check for this mode of failure. Two specimens were tested to evaluate the results of the analytical unbraced length determination process. The tests results were used to better model the contribution of the web-to-column flange double angle connection on the stability of the castellated beam. / Master of Science
4

Feasibility of open web rafters constructed of single angles

HagenBurger, William C. 14 April 2009 (has links)
The purpose of the research reported here was to determine if single angles can be used for chord and web members in lightweight steel open web rafters, and if so to determine what effect the single angles have on the design of the rafter's members. A computer model was constructed to determine the effects of a unsymetric cross section coupled with eccentric loadings of the members on out-or-plane displacements, and bending moments and stresses in the chord and web members. This computer model modeled the eccentricities and unsymetric section properties of the single angles. A study of the effect of out-or-plane bracing on the bending moments and stresses was also conducted. Finally various web configurations (angle web members on the same side, alternating, and opposite) were studied to determine their effect on moments in the web and chord members, along with their effect on out-or-plane displacements. A preliminary design procedure for chord and web members using the new AISC ""Specification For Allowable Stress Design of Single Angle Members" is presented. Finally suggestions on out-of-plane bracing and connections are made. / Master of Science
5

Análise de vigas casteladas e vigas casteladas mistas / Analysis of castellated beams and composite castellated beams

Brinkhus, Raquel Nailê January 2015 (has links)
As vigas casteladas são fabricadas a partir do corte em zigue-zague da alma de perfis I, após são deslocados e soldados, fazendo com que a viga tenha uma expansão na altura, porém sem aumentar a massa do perfil. As mesmas voltaram a ser uma opção competitiva devido aos avanços tecnológicos, que possibilitam a automação do corte e solda da alma do perfil e com o inicio das produções de perfis I laminados no Brasil em 2002. Apresenta grandes vantagens proporcionando a passagem de dutos e tubulações, aumento na rigidez no plano de flexão e boa estética. O presente trabalho apresenta um estudo analítico-numérico realizado com objetivo de verificar o comportamento de vigas casteladas e vigas casteladas mistas, a fim de apresentar e/ou propor dimensionamentos conforme a norma brasileira para as mesmas. Os trabalhos apresentados por Cimadevila (2000) e Veríssimo (2012) foram utilizados para formulação da análise de vigas casteladas. O trabalho de Lawson (2011) que aborda vigas casteladas mistas com aberturas (circulares e retangulares), que é baseado no EUROCODE 3 (2005), foi utilizado para formulação da metodologia de análise de vigas casteladas mistas. Foram realizadas planilhas para análise de vigas casteladas e vigas mistas com aberturas utilizando as metodologias estudadas, e planilhas de análise de vigas casteladas mistas com a metodologia proposta. Utilizando-se o software ANSYS as planilhas e metodologias puderam ser testadas e validadas. Foram selecionados alguns projetos de dimensionamento para comparar vigas de alma cheia, vigas casteladas, vigas mistas, vigas mistas com aberturas e vigas mistas casteladas. / Castellated beams are made of metal I-beams, in which the webs are first divided by a lengthwise zigzag cut, then these parts are welded together in order to join the peaks of both parts, thus increasing its depth and strength, without mass increasing. Castellated beams are again competitive due to technological advances, which enabled automatic cut and welding the web of the I-beams, and with the beginning of the production of rolled metal I-beams in Brazil in 2002. They exhibit great advantages, such as passing of ducts and pipes, increasing bending stiffness, and having good aesthetics. This work presents analytical and numerical studies looking for analysis the behavior of castellated beams and composite castellated beams in order to develop design methods satisfying the corresponding Brazilian code. The castellated beams analysis were based in the works of Cimadevila (2000) and Veríssimo (2012). The work of Lawson (2011), which concerns composite castellated beams and is based on EUROCODE 3 (2005), was used for the formulation of the methodology of the analysis of composite castellated and cellular beams. Spreadsheets were developed for analysis of castellated beams and composite beams with web openings, using both, the studied methodologies and the suggested methodologies for the composite beams. Using ANSYS software, it was possible to test and validate the developed spreadsheets. Design projects of full web beams, castellated beams, composite beams, composite castellated beams and composite beams with web openings were selected for comparison.
6

Análise de vigas casteladas e vigas casteladas mistas / Analysis of castellated beams and composite castellated beams

Brinkhus, Raquel Nailê January 2015 (has links)
As vigas casteladas são fabricadas a partir do corte em zigue-zague da alma de perfis I, após são deslocados e soldados, fazendo com que a viga tenha uma expansão na altura, porém sem aumentar a massa do perfil. As mesmas voltaram a ser uma opção competitiva devido aos avanços tecnológicos, que possibilitam a automação do corte e solda da alma do perfil e com o inicio das produções de perfis I laminados no Brasil em 2002. Apresenta grandes vantagens proporcionando a passagem de dutos e tubulações, aumento na rigidez no plano de flexão e boa estética. O presente trabalho apresenta um estudo analítico-numérico realizado com objetivo de verificar o comportamento de vigas casteladas e vigas casteladas mistas, a fim de apresentar e/ou propor dimensionamentos conforme a norma brasileira para as mesmas. Os trabalhos apresentados por Cimadevila (2000) e Veríssimo (2012) foram utilizados para formulação da análise de vigas casteladas. O trabalho de Lawson (2011) que aborda vigas casteladas mistas com aberturas (circulares e retangulares), que é baseado no EUROCODE 3 (2005), foi utilizado para formulação da metodologia de análise de vigas casteladas mistas. Foram realizadas planilhas para análise de vigas casteladas e vigas mistas com aberturas utilizando as metodologias estudadas, e planilhas de análise de vigas casteladas mistas com a metodologia proposta. Utilizando-se o software ANSYS as planilhas e metodologias puderam ser testadas e validadas. Foram selecionados alguns projetos de dimensionamento para comparar vigas de alma cheia, vigas casteladas, vigas mistas, vigas mistas com aberturas e vigas mistas casteladas. / Castellated beams are made of metal I-beams, in which the webs are first divided by a lengthwise zigzag cut, then these parts are welded together in order to join the peaks of both parts, thus increasing its depth and strength, without mass increasing. Castellated beams are again competitive due to technological advances, which enabled automatic cut and welding the web of the I-beams, and with the beginning of the production of rolled metal I-beams in Brazil in 2002. They exhibit great advantages, such as passing of ducts and pipes, increasing bending stiffness, and having good aesthetics. This work presents analytical and numerical studies looking for analysis the behavior of castellated beams and composite castellated beams in order to develop design methods satisfying the corresponding Brazilian code. The castellated beams analysis were based in the works of Cimadevila (2000) and Veríssimo (2012). The work of Lawson (2011), which concerns composite castellated beams and is based on EUROCODE 3 (2005), was used for the formulation of the methodology of the analysis of composite castellated and cellular beams. Spreadsheets were developed for analysis of castellated beams and composite beams with web openings, using both, the studied methodologies and the suggested methodologies for the composite beams. Using ANSYS software, it was possible to test and validate the developed spreadsheets. Design projects of full web beams, castellated beams, composite beams, composite castellated beams and composite beams with web openings were selected for comparison.
7

Análise de vigas casteladas e vigas casteladas mistas / Analysis of castellated beams and composite castellated beams

Brinkhus, Raquel Nailê January 2015 (has links)
As vigas casteladas são fabricadas a partir do corte em zigue-zague da alma de perfis I, após são deslocados e soldados, fazendo com que a viga tenha uma expansão na altura, porém sem aumentar a massa do perfil. As mesmas voltaram a ser uma opção competitiva devido aos avanços tecnológicos, que possibilitam a automação do corte e solda da alma do perfil e com o inicio das produções de perfis I laminados no Brasil em 2002. Apresenta grandes vantagens proporcionando a passagem de dutos e tubulações, aumento na rigidez no plano de flexão e boa estética. O presente trabalho apresenta um estudo analítico-numérico realizado com objetivo de verificar o comportamento de vigas casteladas e vigas casteladas mistas, a fim de apresentar e/ou propor dimensionamentos conforme a norma brasileira para as mesmas. Os trabalhos apresentados por Cimadevila (2000) e Veríssimo (2012) foram utilizados para formulação da análise de vigas casteladas. O trabalho de Lawson (2011) que aborda vigas casteladas mistas com aberturas (circulares e retangulares), que é baseado no EUROCODE 3 (2005), foi utilizado para formulação da metodologia de análise de vigas casteladas mistas. Foram realizadas planilhas para análise de vigas casteladas e vigas mistas com aberturas utilizando as metodologias estudadas, e planilhas de análise de vigas casteladas mistas com a metodologia proposta. Utilizando-se o software ANSYS as planilhas e metodologias puderam ser testadas e validadas. Foram selecionados alguns projetos de dimensionamento para comparar vigas de alma cheia, vigas casteladas, vigas mistas, vigas mistas com aberturas e vigas mistas casteladas. / Castellated beams are made of metal I-beams, in which the webs are first divided by a lengthwise zigzag cut, then these parts are welded together in order to join the peaks of both parts, thus increasing its depth and strength, without mass increasing. Castellated beams are again competitive due to technological advances, which enabled automatic cut and welding the web of the I-beams, and with the beginning of the production of rolled metal I-beams in Brazil in 2002. They exhibit great advantages, such as passing of ducts and pipes, increasing bending stiffness, and having good aesthetics. This work presents analytical and numerical studies looking for analysis the behavior of castellated beams and composite castellated beams in order to develop design methods satisfying the corresponding Brazilian code. The castellated beams analysis were based in the works of Cimadevila (2000) and Veríssimo (2012). The work of Lawson (2011), which concerns composite castellated beams and is based on EUROCODE 3 (2005), was used for the formulation of the methodology of the analysis of composite castellated and cellular beams. Spreadsheets were developed for analysis of castellated beams and composite beams with web openings, using both, the studied methodologies and the suggested methodologies for the composite beams. Using ANSYS software, it was possible to test and validate the developed spreadsheets. Design projects of full web beams, castellated beams, composite beams, composite castellated beams and composite beams with web openings were selected for comparison.
8

Simulação numérica do comportamento estrutural de vigas alveolares mistas de aço e concreto / Numerical Modeling of Structural Behavior of Composite Castellated Beams of Steel and Concrete

Ferrari, Giuliana de Angelo 04 February 2013 (has links)
Made available in DSpace on 2015-03-26T13:28:13Z (GMT). No. of bitstreams: 1 texto completo.pdf: 4285761 bytes, checksum: aedb2e19642633492bc8af806dae08de (MD5) Previous issue date: 2013-02-04 / Castellated beams are fabricated from rolled I-beams. The web of the section is cut by flame along the longitudinal axis according to a zigzag trace. The two halves are then welded together to produce a beam of greater depth with a sequence of openings in the web. The resulting beam has a larger section modulus and greater bending rigidity than the original section, without an increase in weight. Composite structures of steel and concrete have been an alternative increasingly employed in the construction industry by offering constructive and economic advantages over other building technologies. The interest in composite castellated beams arises as a result of the use of castellated beams in floor systems, since the composite solution can further contribute increasing inertia and ultimate strength.. The main objective of this work is the evaluation of the structural behavior of composite castellated beams of steel and concrete, obtained from numerical simulation using the Finite Element Method. For development of the numerical model the computer program ABAQUS was used considering geometric and material nonlinearity. The numerical model allows to consider different degrees of interaction between steel and concrete with partial or full transmission of the shear flow that occurs at the interface between the concrete slab and the steel beam. In order to validate the numerical model, five experimental models of composite castellated beams of steel and concrete, with symmetrical openings, whose test results are available in the literature, were analyzed. The numerical model is able to adequately represent the structural behavior of composite castellated beams of steel and concrete, including the ultimate capacity and failure modes identified. The strategies adopted to simulate the interaction between steel and concrete allowed to reproduce the phenomena observed in experimental models for different types of openings and different degrees of interaction between steel and concrete. / As vigas alveolares são obtidas de perfis de aço tipo I ou H, a partir da expansão da alma dos mesmos, o que gera um ganho de inércia, mantendo-se a mesma massa do perfil original. As estruturas mistas de aço e concreto têm sido uma alternativa cada vez mais empregada na construção civil por oferecerem vantagens construtivas e econômicas em relação a outras tecnologias construtivas. O interesse por vigas alveolares mistas surge como consequência do uso de vigas alveolares em sistemas de piso, já que a solução mista pode contribuir ainda mais com o ganho de inércia e de resistência última. O objetivo principal deste trabalho é a avaliação do comportamento estrutural de vigas alveolares mistas de aço e concreto, obtidas a partir de perfis laminados, por meio de simulação numérica utilizando o Método dos Elementos Finitos. Para o desenvolvimento do modelo numérico utilizou-se o programa computacional ABAQUS, considerando-se a não-linearidade material e geométrica. O modelo numérico desenvolvido permite considerar diferentes graus de interação entre aço e concreto, com a transmissão de parte (interação parcial) ou da totalidade (interação completa) do fluxo de cisalhamento que ocorre na interface entre a laje de concreto e a viga de aço. Para validação do modelo numérico foram analisados cinco modelos experimentais de vigas alveolares mistas de aço e concreto, com aberturas simétricas, cujos resultados de ensaio estão disponíveis na literatura. O modelo numérico desenvolvido foi capaz de representar adequadamente o comportamento estrutural de vigas alveolares mistas de aço e concreto, tanto no que se refere à capacidade última dos elementos estruturais, como no que se refere aos modos de colapso identificados. As estratégias adotadas para simular a interação entre aço e concreto permitiram reproduzir os fenômenos observados nos modelos experimentais, para os diferentes tipos de abertura e graus de interação entre aço e concreto.
9

[en] FINITE ELEMENT MODELING OF CASTELLATED AND EXPANDED CASTELLATED STEEL BEAMS / [pt] MODELAGEM POR ELEMENTOS FINITOS DE VIGAS DE AÇO CASTELADAS E VIGAS CASTELADAS EXPANDIDAS

BRUNO VICENTE DIAS 12 February 2019 (has links)
[pt] As vigas de aço com abertura de alma propiciam a passagem de tubulações de serviços e instalações, fornecendo boa capacidade de resistência aos esforços cortantes. As vigas casteladas e as vigas celulares apresentam limitações de dimensões da abertura que estão ligadas à altura do perfil base, geralmente produzindo-se um perfil 50 por cento maior em altura. Neste trabalho, são estudadas as vigas casteladas expandidas em altura, através da soldagem de uma chapa complementar de alma, de modo a se obter vigas de maior inércia, mais leves e com maiores aberturas. O presente trabalho aborda os resultados obtidos através da modelagem por elementos finitos com análise não linear física e geométrica, com vistas a investigação do comportamento estrutural quanto a resistência da seção transversal e rigidez visando-se a redução de custos de fabricação pela eliminação da soldagem de chapas de reforço na região da abertura. / [en] Steel beams with web openings allow integration between structural and tubular services and facilities, providing good shear strength capacity. The castellated and cellular beams have limitations due to this web openings and results in a profile with 50 per cent higher depth. In this research, depth expanded castellated beams with the use of an additional welded plate will be studied, aiming the obtainment of higher inertia as well as wider openings on lighter beams. The present work addresses the results results obtained through the finite element method using physical and geometric nonlinear analysis, observing the structural behavior regarding stiffness and strength in order to reduce manufacturing costs since the reinforcement plates in the areas will no more be required.
10

Análise analítica e numérica de vigas casteladas com diferentes padrões geométricos / Analytical and numerical analysis of castellated beams with different geometric patterns

Melo, Pedro Henrique Pedrosa de 22 October 2018 (has links)
Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2018-12-11T11:29:18Z No. of bitstreams: 2 Dissertação - Pedro Henrique Pedrosa de Melo - 2018.pdf: 47578131 bytes, checksum: 8fbf8b63ebd4d5db7f6f6223bd26712a (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2018-12-12T10:37:34Z (GMT) No. of bitstreams: 2 Dissertação - Pedro Henrique Pedrosa de Melo - 2018.pdf: 47578131 bytes, checksum: 8fbf8b63ebd4d5db7f6f6223bd26712a (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-12-12T10:37:34Z (GMT). No. of bitstreams: 2 Dissertação - Pedro Henrique Pedrosa de Melo - 2018.pdf: 47578131 bytes, checksum: 8fbf8b63ebd4d5db7f6f6223bd26712a (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-10-22 / Fundação de Amparo à Pesquisa do Estado de Goiás - FAPEG / The present paper deals with the main subjects related to castellated steel beams, initially showing a brief review of the history of emergence and use of the world, highlighting the characteristics that favored the growth of use and the difficulties of its use. The main failure modes are characterized, highlighting the analytical procedures available in the literature to circumvent them, in order to propose a calculation procedure for the design. The proposed procedure is evaluated through the experimental result of four surveys. The work also presents numerical modeling, using Finite Element Method (FEM), for beams available in the technical literature, in order to complement the analysis of beam behavior during loading and to verify the validity of the proposed numerical model, mainly in relation to the analysis criteria adopted in the numerical model, such as von Mises stress distribution, isotropic hardening and tensile stress behavior of the steel using the multilinear graph, also available in the technical literature. The validity allows the proposed beams, with Anglo-Saxon geometry, Litzka and Peiner, to have reliability of analysis of the model, and for the proposed loading the Anglo-Saxon beam obtained greater resistance, mainly due to the small distance between the holes and also the lowest overall width of the aperture. The results of the numerical models, via MEF, showed good precision when compared to the experimental results, showing that MEF is an extremely useful tool for nonlinear analysis, provided the model is properly calibrated. Another important result is the resistance values presented by the proposed analytical procedure, which presents a good approximation to the actual values of the experiment and also the resistance values obtained in the proposed numerical models, and can be adopted for the practical dimensioning of these beams. / O presente trabalho aborda os principais assuntos relacionados às vigas alveolares casteladas, mostrando inicialmente uma breve revisão do histórico de surgimento e utilização pelo mundo, ressaltando as características que favoreceram o crescimento de utilização e quais as dificuldades de seu uso. Os principais modos de falha são caracterizados, ressaltando os procedimentos analíticos disponíveis na literatura para contorná-los, de forma a se propor um procedimento de cálculo para o dimensionamento. O procedimento proposto é avaliado por meio do resultado experimental de quatro pesquisas. O trabalho também apresenta uma modelagem numérica, via Método dos Elementos Finitos (MEF), para vigas disponíveis na literatura técnica, de forma a complementar a análise do comportamento das vigas durante o carregamento e também verificar a validade do modelo numérico proposto, principalmente em relação aos critérios de análise adotados no modelo numérico, como distribuição das tensões de von Mises, endurecimento isotrópico e comportamento tensão x deformação do aço por meio do gráfico multilinear, também disponível na literatura técnica. A validade permite que as vigas propostas, com geometria Anglosaxão, Litzka e Peiner, possuam confiabilidade de análise do modelo, sendo que para o carregamento proposto a viga Anglo-saxão obteve maior resistência, devido principalmente pela pequena distância entre os furos e também a menor largura total da abertura. Os resultados dos modelos numéricos, via MEF, apresentaram boa precisão quando comparado aos resultados experimentais, mostrando que que o MEF é uma ferramenta extremamente útil para análises não-lineares, desde que o modelo esteja devidamente calibrado. Outro resultado importante são os valores de resistência apresentados pelo procedimento analítico proposto, ao qual apresenta boa aproximação aos valores reais do experimento e também dos valores de resistência obtidos nos modelos numéricos propostos, podendo, assim, ser adotado para o dimensionamento prático dessas vigas.

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