Dissertations / Theses on the topic 'Composite beam'
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1
Elghazouli, Ahmed Youssef. "Earthquake resistance of composite beam-columns." Thesis, Imperial College London, 1991. http://hdl.handle.net/10044/1/7906.
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Chandrasekaran, Ganesh. "Dynamic analysis of a composite moving beam." Morgantown, W. Va. : [West Virginia University Libraries], 2000. http://etd.wvu.edu/templates/showETD.cfm?recnum=1526.
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Thesis (M.S.)--West Virginia University, 2000.Title from document title page. Document formatted into pages; contains xi, 159 p. : ill. Includes abstract. Includes bibliographical references (p. 156-159).
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LeBlanc, David N. "Beam shear connections to HSS composite columns." Thesis, McGill University, 1985. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=63273.
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Oh, Seung-Taek. "Impact response of pultruded composite beam structure." Thesis, Imperial College London, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.431767.
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Dissanayake, Udaya Indrajith. "The influence of the composite beam-to-steel column joint on the behaviour of composite beams in frames." Thesis, University of Sheffield, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.389752.
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Davis, Richard Anthony. "The Effects of a Damage Arrestment Device on the Mechanical Behavior of Sandwich Composite Beams Under Four-Point Bending." DigitalCommons@CalPoly, 2011. https://digitalcommons.calpoly.edu/theses/506.
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The demand for an insert on composite sandwich structures to aid in the arrestment of face-core delamination is of great need. This research studies the use of a damage arrestment device (DAD) that connects the carbon fiber face sheets to the foam core to find whether an increase in the structural integrity of the sandwich beam results. Experimental analysis was employed to test the samples and was verified by a theoretical and finite element approach.
The mechanical properties of LTM45/CF1803 pre-impregnated carbon fiber and Last-A-foam FR 6710 polyvinylchloride foam were experimentally analyzed using ASTM D3039 and ASTM D1621 standards respectively to verify the manufacturer’s data for the given material. With all the mechanical data, the effects of adding DAD keys to a delaminated composite sandwich beam were studied under a four-point bending test using ASTM standard D6272 and compared with non-delaminated beams to see if an increase in ultimate strength could be achieved. The initial delamination in the beams under consideration was one inch in length and located in between the loaded span of the beam. Two control beams were utilized for comparison: one with no defects, and another with a one inch delamination introduced at the face-core interface. The DAD keys were added in two different configurations to potentially stop the delamination propagation and increase the ultimate strength. In the first configuration DAD keys were added 0.25 inches on either side of the initial delamination in the transverse direction and provided a significant increase in strength over the delaminated control beam. The second configuration had a DAD key running along the longitudinal axis of the sandwich beam and resulted in a significant increase in ultimate strength over the delaminated control beam. After testing ten successful samples for each of the six different configurations, it was concluded that the addition of DAD keys in both configurations significantly increased the structural integrity of both the delaminated and non-delaminated control beams.
With all the experimental data acquired, finite element models were created in COSMOS. The purpose of the finite element analysis was to validate the experimental results by comparing the deflections of the beam subjected to four-point bending during the experiment to the deflections found numerically. The deflections for the various DAD key configurations found in the experimental work were in agreement with the finite element results.
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Kim, Dong Keon. "A Database for Composite Columns." Thesis, Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/7126.
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A database of composite column tests was augmented and utilized to evaluate the proposed AISC 2005 provisions. The database consists of column and beam-column steel-concrete columns (or encased, SRC), circular concrete filled tubes (CCFT), and rectangular concrete filled tube (RCFT). Information on material and geometric properties on each specimen was summarized. The database includes 119 SRC columns, 136 SRC beam-columns, 312 circular CFT columns, 198 circular CFT beam-columns, 222 rectangular CFT columns and 194 rectangular CFT beam-columns. The database has a total of 1181 specimens, an addition of 451 specimens over those in the original database (Aho 1996).
The data on each specimen was analyzed and compared with current design provision for composite columns (AISC 1999 and Eurocode 4), and reassessed by the upcoming 2005 AISC specification. The data indicates that the Eurocode gives good predictions for columns and the AISC 2005 method performs very well for beam-columns. For rectangular CFT columns, all three methods predict the ultimate capacity very well. The main improvement for the AISC 2005 method is its ability to handle specimens which have high yield stress and/or high strength concrete.
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Jackson, Rahsean LaNaul. "Vibration and Flexural Strength Characteristics of Composite Castellated Beams." Thesis, Virginia Tech, 2002. http://hdl.handle.net/10919/31242.
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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 specimensâ moment strength was verified based on span, beam properties, concrete slab, and amount of shear connection.
Master of Science
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Al, Shawawreh Sewar F. "Three-Dimensional Finite Element Modeling of Non-Composite and Composite Adjacent Box Beam Bridges." Ohio University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1534516905239026.
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Heidarpour, Amin Civil & Environmental Engineering Faculty of Engineering UNSW. "Behaviour of steel and steel-concrete composite beams and beam-to-column connetions at elevated temperatures." Awarded by:University of New South Wales. Civil & Environmental Engineering, 2007. http://handle.unsw.edu.au/1959.4/40555.
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The current research work investigates the behaviour of steel and composite beams as well as beam-to-column connections at elevated temperatures. Significant attention is needed to identify the main issues. as the behaviour is profoundly different from that at ambient temperature. Local buckling of the beam flange outstands has been found to be highly significant in accelerating the development of catenary action in fire, since this action is reliant on hinges forming which may result from local buckling. Local buckling of the beam web, which experiences a non-uniform temperature variation, is also important because the mechanical properties of the steel are degraded non-uniformly from their ambient values. Current formulations for web buckling at ambient temperature therefore need substantial revision at elevated temperatures. Very large compressive forces are developed within the beams initially and these induce large stresses in the column web; hitherto this has not been considered. Developing a formulation representing the mechanics of this potential failure zone in the column web in the compression region of the connection is a useful and needed addition to research in the topic. Predicting the critical temperature in a connection that causes failure of the bolts, end plate and column flange in the tension zone of the connection is considered in this research work. An elastic analysis of a panel zone in a rigid or semi-rigid joint in a steel frame, which is based on simple equilibrium considerations that takes into account the shear and flexural deformations of the panel zone, is developed at elevated temperatures. In order to model the structural response of a composite beam restrained by cooler members in a steel compartment fire in a frame structure at elevated temperature, recourse is needed to a geometric nonlinear formulation, since the beam transverse deflections are not negligible and the axial eompressive force in the member is also substantial at the early stages of the fire. This thesis presents such a formulation, which incorporates partial interaction between the concrete slab and steel component, as well as the degradation of the stiffnesses of the components of the composite beam prior to yield at elevated temperature.
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Rackham, James William. "The design of haunched composite beam frames for buildings." Thesis, City University London, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.358221.
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Coyle, Neil Robert. "Development of fully composite steel-concrete-steel beam elements." Thesis, University of Dundee, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.270046.
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Steel-Concrete-Steel (SCS) composite construction consists of two relatively thin steel plates with the space between filled with concrete. Various forms of this construction exist, using overlapping shear studs and single bar connectors to provide shear reinforcement to the concrete and provide a shear transfer at the interface. The problem with current systems that rely purely upon shear studs or bar connectors is that they are prone to slip between the steel faceplates and concrete core. This slip leads to a loss of composite action causing a loss of stiffness and a reduced fatigue life. An extensive experimental programme consisting of 32 beam specimens and 34 other small scale specimens formed the basis for the study of the behaviour of surfaced SCS specimens under a variety of load conditions. The results of this test program showed that surfaced SCS specimens behaved in a more composite manner. This increase in composite action manifested itself in a number of ways. • Reduced slip between steel plate and concrete core • Increased stiffness of specimen • More even crack distribution This extensive experimental study was backed up with an analytical study to understand and predict the behaviour of the surfaced SCS elements. This study has led to a new method of predicting the capacity of such sections, to a greater degree of accuracy than current methods allow. Further to this a FE parametric study was carried out to investigate the sensitivity of the elements to changes in the main geometrical and material variables.
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Van, Nosdall Stephen Paul. "Experiments on a Hybrid Composite Beam for Bridge Applications." Thesis, Virginia Tech, 2013. http://hdl.handle.net/10919/23106.
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This thesis details a study of the structural behavior of Hybrid-Composite Beams (HCB) consisting of a fiber reinforced polymer (FRP) shell with a concrete arch tied with steel prestressing strands. The HCB offers advantages in life cycle costs through reduced transportation weight and increased corrosion resistance. By better understanding the system behavior, the proportion of load in each component can be determined, and each component can be designed for the appropriate forces. A long term outcome of this research will be a general structural analysis framework that can be used by DOTs to design HCBs as rapidly constructible bridge components. This study focuses on identifying the load paths and load sharing between the arch and FRP shell. Testing was performed by applying point loads on simple span beams (before placing the bridge deck) and a three beam skewed composite bridge system. Curvature from strain data is used to find internal bending forces, and the proportion of load within the arch is found. Additionally, a stress integration method is used to confirm the internal force contributions. The tied arch carries about 80% of the total load for the non-composite case without a bridge deck. When composite with a bridge deck, the arch has a minimal contribution to the HCB stiffness and strength as it is below the neutral axis. For this composite case the FRP shell and prestressing strands resist about 85% of the applied load while the bridge deck carries the remaining 15% to the end diaphragms and bearings.
Master of Science
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NITTALA, GANESH KUMAR. "COMPOSITE BEAM WITH WARPAGE FOR EXPLICIT FINITE ELEMENT SIMULATION." University of Cincinnati / OhioLINK, 2003. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1060894192.
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Rex, Clinton O. "Behavior of composite semi-rigid beam-to-girder connections." Thesis, This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-07102009-040338/.
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Heidarpour, Amin Civil & Environmental Engineering Faculty of Engineering UNSW. "Behaviour of steel and steel-concrete composite beams and beam-to-column connections at elevated temperatures." Awarded by:University of New South Wales, 2007. http://handle.unsw.edu.au/1959.4/37234.
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The current research work investigates the behaviour of steel and composite beams as well as beam-to-column connections at elevated temperatures. Significant attention is needed to identify the main issues, as the behaviour is profoundly different from that at ambient temperature. Local buckling of the beam flange outstands has been found to be highly significant in accelerating the development of catenary action in fire, since this action is reliant on hinges forming which may result from local buckling. Local buckling of the beam web, which experiences a non-uniform temperature variation, is also important because the mechanical properties of the steel are degraded non-uniformly from their ambient values. Current formulations for web buckling at ambient temperature therefore need substantial revision at elevated temperatures. Very large compressive forces are developed within the beams initially and these induce large stresses in the column web; hitherto this has not been considered. Developing a formulation representing the mechanics of this potential failure zone in the column web in the compression region of the connection is a useful and needed addition to research in the topic. Predicting the critical temperature in a connection that causes failure of the bolts, end plate and column flange in the tension zone of the connection is considered in this research work. An elastic analysis of a panel zone in a rigid or semi-rigid joint in a steel frame, which is based on simple equilibrium considerations that takes into account the shear and flexural deformations of the panel zone, is developed at elevated temperatures. In order to model the structural response of a composite beam restrained by cooler members in a steel compartment fire in a frame structure at elevated temperature, recourse is needed to a geometric nonlinear formulation, since the beam transverse deflections are not negligible and the axial compressive force in the member is also substantial at the early stages of the fire. This thesis presents such a formulation, which incorporates partial interaction between the concrete slab and steel component, as well as the degradation of the stiffnesses of the components of the composite beam prior to yield at elevated temperature.
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Fior, Valerie F. "A beam test for adhesives." Thesis, Virginia Tech, 1988. http://hdl.handle.net/10919/43969.
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The strength of materials solution for a new bonded cantilever beam test specimen to determine adhesive shear properties is reviewed and discussed. A parametric analysis for the adhesive shear stress and for the end deflection reveals the specimen dimensions required for reliable bonded adhesive shear properties determination. Recommendations are provided for conducting reproducible tests. A pure and quasi-uniform shear test for stiff adhesives is proposed.
Analytical solutions are compared with Finite Element solutions from VISTA and NOVA for the stresses in the adhesive. It appears that the assumption of pure shear is nearly valid even for very stiff and/or very thick adhesives. In order to increase the end point deformations for stiff adhesives, a modified specimen is proposed. Three-dimensional effects through the thickness of the adhesive layer are studied with the program ABAQUS.
Experiments were performed using the two methods derived from theory and good correlation between theory and experiment were obtained with some restrictions. For both methods, experimental results underlined the need for defining proper specimen geometry prior to testing. Simple numerical codes are proposed to facilitate this purpose.Master of Science
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Luk, Herman Chi Yung. "FRP-strengthened beam : interfacial failure and development of empirical design approach /." View Abstract or Full-Text, 2002. http://library.ust.hk/cgi/db/thesis.pl?CIVL%202002%20LUK.
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Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2002.Includes bibliographical references (leaves 216-222). Also available in electronic version. Access restricted to campus users.
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Ho, Jimmy Cheng-Chung. "Modeling spanwise nonuniformity in the cross-sectional analysis of composite beams." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/29638.
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Thesis (Ph.D)--Aerospace Engineering, Georgia Institute of Technology, 2009.Committee Chair: Hodges, Dewey; Committee Member: Bauchau, Olivier; Committee Member: Volovoi, Vitali; Committee Member: White, Donald; Committee Member: Yu, Wenbin. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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Brinkhus, Raquel Nailê. "Análise de vigas casteladas e vigas casteladas mistas." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2015. http://hdl.handle.net/10183/115556.
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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.
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Kavaliauskas, Saulius. "Behaviour of timber-concrete composite beam interconnection with inclined screws." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2010. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2010~D_20100317_151205-00517.
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The dissertation investigates the behaviour of timber-concrete connections with inclined screws – the load carrying capacity and deformability. The essen¬tial objects of investigation are the load carrying capacity of inclined screws; the modules of connection slip deformation, and the mechanical properties of mate¬rials and ware of which the connection is made. The load-carrying capacity of the connection depends on the properties of the material of connected member and the connectors, on which depends the strength and stiffness of the composite member. The main aim of dissertation is to create the connection load carrying capacity predicting model, based on the more realistic behaviour of the material of connected members; to prepare the simplified approach for load-carrying capacity predicting model for composite timber-concrete connections within at any angle in respect to timber grain in¬clined crews. The paper approaches a few major tasks such as the choice of suitable load-carrying capacity predicting base model; preparing it to composite timber-con¬crete connections with inclined screws; the experimental investigation of con¬nection with inclined screws under long- and short term loading; the experi¬mental investigation of properties of connected materials and type of used con¬nectors; the evaluation of created predictive model based on results also of other researchers experimental investigations.Disertacijoje nagrinėjama kompozitinės medinės-betoninės jungties su įžambiai šlyties plokštumai orientuotais medsraigčiais elgsena – laikomoji galia ir deformacinės savybės. Pagrindiniai tyrimų objektai yra įžambiai medienos pluoštui orientuotų medsraigčių laikomoji galia, slinkties deformacijų moduliai ir mechaninės jungtį sudarančių elementų savybės, veikiančios jungties elgseną. Nuo medsraigčio ašies posvyrio kampo, deformacinių po medsraigčiu glemžiamos ir ištraukiamos medienos ir lenkiamo medsraigčio savybių priklauso ir jungties irties pobūdis, laikomoji galia ir slinkties deformacijų moduliai, o nuo pastarųjų – kompozitinio elemento stiprumas ir standumas. Pagrindinis disertacijos tikslas yra sukurti skaičiavimo modelį tokių jungčių laikomajai galiai nuspėti, kuo tiksliau atsižvelgiant į medžiagų ir elementų mechanines savybes; pateikti supaprastintą skaičiuojamąjį modelį, skirtą bet kokiu kampu medienos pluošto atžvilgiu įsriegtų medsraigčių laikomajai galiai nuspėti. Darbe sprendžiami keli pagrindiniai uždaviniai: tinkamo pamatinio jungties laikomąją galią vertinančio skaičiuojamojo modelio parinkimas, jo pritaikymas įžambiai medienos pluoštui orientuotiems medsraigčiams; trumpalaikis ir ilgalaikis eksperimentinis įžambinės medsraigtinės jungties laikomosios galios tyrimas ir vertinimas; kitų autorių eksperimentinių rezultatų vertinimas sukurtajam jungties laikomąją galią vertinančiam modeliui pagrįsti.
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Kunwar, Sushil. "Comprehensive Evaluation of Composite Core Walls for Low-Seismic Force and Wind Load Applications." University of Cincinnati / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1613750905724949.
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Broderick, Brian Michael. "Seismic testing, analysis and design of composite frames." Thesis, Imperial College London, 1994. http://hdl.handle.net/10044/1/7366.
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LOPES, ELVIS DINATI CHANTRE. "NON-LINEAR DYNAMICAL ANALYSIS OF COMPOSITE FLOORS CONSIDERING THE EFFECTS OF PARTIAL INTERACTION AND BEAM TO COLUMN AND BEAM TO BEAM CONNECTIONS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2012. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=21173@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO
O crescimento dos problemas de vibrações excessivas em edificações oriundos de atividades humanas rítmicas tem conduzido à necessidade de desenvolvimento de critérios específicos para projetos estruturais submetidos à ação dessas cargas dinâmicas. Esta foi uma das motivações para o desenvolvimento de uma metodologia de análise para investigação da resposta dinâmica de sistemas estruturais de pisos mistos (aço-concreto). Objetiva-se verificar a influência da interação aço-concreto (interação total e parcial) e, bem como, das ligações estruturais (ligações viga-coluna e viga-viga), sobre a resposta dinâmica não linear de pisos mistos (aço-concreto). Deste modo, são utilizados três modelos de carregamento dinâmico representativos das atividades humanas rítmicas referentes a saltos à vontade e ginástica aeróbica. As cargas dinâmicas são obtidas por meio de testes experimentais e, também, com base em normas e recomendações internacionais de projeto. Com referência a interação aço-concreto, vários tipos de conectores (tipo stud e perfobond) são considerados ao longo da investigação. Mesmo sabendo-se que a análise de vibrações de pisos induzidas por atividades humanas tem sido alvo de inúmeras investigações ao longo dos últimos dois séculos (1828-2012), os autores desconhecem na literatura técnica um trabalho de pesquisa tão abrangente, no que diz respeito à análise dinâmica não linear de pisos mistos (aço-concreto) submetidos à ação de atividades humanas rítmicas, com base na consideração dos efeitos dos conectores (interação aço-concreto) e das ligações (viga-coluna e viga-viga). Diante do exposto, o quadro global investigado neste trabalho de pesquisa demonstra, claramente, um indicativo de que os critérios de projeto devem levar em conta o caráter dinâmico da excitação e, especialmente, a influência da interação aço-concreto e das ligações estruturais, no que tange a verificação dos estados limites de utilização (conforto humano), associados ao comportamento estrutural de pisos mistos de edificações.
The increasing incidence of building vibration problems due to human activities led to a specific design criterion to be addressed in structural design. This was the main motivation for the development of a design methodology centred on the steel-concrete composite floors non-linear dynamic response submitted to loads due to human rhythmic activities. This way, the main objective of this work is to investigate the influence of steel-concrete interaction degree (from total to various levels of partial interaction) and the beam-to-column and beam-to-beam connections effect over the non-linear dynamic behaviour of composite floors. Thus, three dynamic loading models were utilized, in order to simulate human rhythmic activities such as jumping and aerobic gymnastics. The dynamic loads were obtained through experimental tests and based on international design codes and recommendations. Regarding the steel-concrete interaction degree, the stud and perfobond connectors are considered in this investigation. Even though this topic has been studied in the technical literature for nearly two centuries, the steel-concrete composite floors non-linear dynamic analysis submitted to human rhythmic activities has not yet been addressed so comprehensively, as far as the authors are concerned in this investigation, based on the consideration of the connectors (steel-concrete interaction degree) and connections (beam-to-column and beam-to-beam) effects. Considering all aspects mentioned before, the results have demonstrated that the design criteria should include the original nature of the dynamic excitation and, specially, the steel-concrete interaction degree and structural connections effects when the steel-concrete composite floors structural behaviour, related to the serviceability limit states (human comfort) are investigated.
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Schniepp, Timothy John. "Design Manual Development for a Hybrid, FRP Double-Web Beam and Characterization of Shear Stiffness in FRP Composite Beams." Thesis, Virginia Tech, 2002. http://hdl.handle.net/10919/34550.
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Fiber-reinforced polymeric (FRP) composites are being considered for structural members in bridge construction as lighter, more durable alternatives to steel and concrete. Extensive testing and analysis of a pultruded, hybrid double web beam (DWB) developed for use in bridge construction has been conducted at Virginia Tech. A primary purpose of this testing is the development of a structural design guide for the DWB, which includes stiffness and strength data. The design manual also includes design allowables determined through a statistical analysis of test data.
Static testing of the beams, including failure tests, has been conducted in order to determine such beam properties as bending modulus, shear stiffness, failure mode, and ultimate capacity. Measuring and calculating the shear stiffness has proven to be an area of particular interest and difficulty. Shear stiffness is calculated using Timoshenko beam theory which combines the shear stiffness and shear area together along with a shear correction factor, k, which accounts for the nonuniform distribution of shear stress/strain through the cross-section of a structure. There are several methods for determining shear stiffness, kGA, in the laboratory, including a direct method and a multi-span slope method. Herein lays the difficulty as it has been found that varying methods produces significantly different results. One of the objectives of current research is to determine reasons for the differences in results, to identify which method is most accurate in determining kGA, and also to examine other parameters affecting the determination of kGA that may further aid the understanding of this property.
This document will outline the development of the design guide, the philosophy for the selection of allowables and review and discuss the challenges of interpreting laboratory data to develop a complete understanding of shear effects in large FRP structural members.Master of Science
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Kim, Inn B. "Development and analysis of elastically tailored composite star shaped beam sections." Diss., Available online, Georgia Institute of Technology, 2004:, 2003. http://etd.gatech.edu/theses/available/etd-04062004-164703/unrestricted/kim%5Finn%5Fb%5F200312%5Fphd.pdf.
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Ragon, Scott A. "Optimization of composite box-beam structures including effects of subcomponent interaction /." This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-06162009-063327/.
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Song, Ohseop. "Modeling and response analysis of thin-walled beam structures constructed of advanced composite materials." Diss., This resource online, 1990. http://scholar.lib.vt.edu/theses/available/etd-07282008-135316/.
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Treadway, Jason Andrew. "Inelastic behaviour of composite beam-columns subject to extreme loading conditions." Thesis, Imperial College London, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.501214.
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Canning, Lee. "The structural analysis and optimization of an advanced composite / concrete beam." Thesis, University of Surrey, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.365155.
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ERINGER, DAIANA SANTOS. "EXPERIMENTAL STUDY OF COMPOSITE BEAM-COLUMNS WITH HIGH STRENGTH STEEL SECTIONS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2017. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=33897@1.
Full textAbstract:
PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO
Estruturas mistas de aço e concreto estão se tornando cada vez mais viáveis do ponto de vista de execução com custos mais competitivos. Graças às pesquisas e aos estudos desenvolvidos que visam aproveitar ao máximo as vantagens oferecidas pelos materiais concreto e aço, as estruturas mistas vêm sendo cada vez mais utilizadas na construção civil. Neste estudo são apresentadas as configurações estruturais dos pilares mistos e recomendações de projeto de normas vigentes. O objetivo dessa dissertação é avaliar o comportamento experimental de pilares mistos com perfis de aço de alta resistência submetidos a ensaios em escala real. Para tal avaliação, levou-se em consideração as características e propriedades dos materiais que compõem as peças: concreto, aço das armaduras e aço de alta resistência dos perfis U de chapa dobrada. Para atingir o objetivo deste trabalho, foram testados seis elementos mistos com seção transversal formada por dois perfis U de chapa dobrada e concreto armado, formando uma seção retangular. Inicialmente duas colunas foram submetidas à compressão centrada e duas vigas foram testadas à flexão. Posteriormente os dois pilares mistos foram ensaiados com excentricidade de 40 mm no carregamento. Os resultados experimentais foram, então, analisados e comparados com os resultados teóricos calculados com as recomendações da norma brasileira ABNT NBR 8800:2008 e do Eurocode 4, 2004. E os resultados experimentais foram em média coerentes com os teóricos calculados.
Composite structures of steel and concrete are becoming increasingly feasible from the execution point of view, with more competitive costs. Thanks to the work and studies developed that aim to make the most of the advantages offered by both materials, they have been increasingly used in building construction. This study presents the structural configurations of the composite beam-columns and design recommendations using current codes. The objective of this dissertation is to evaluate the experimental behavior of composite beam-columns with high strength steel profiles tested in real scale specimens. For this analysis, the characteristics and properties of the materials that compose the structure were taken into consideration: concrete, reinforcing steel and high strength steel of the cold formed sections. To reach the aims of this work, six composite elements with cross section formed by two channel profiles of folded sheet and reinforced concrete were tested. Initially two columns were subjected to centered compression and two beams were subjected to flexural tests. Subsequently, the composite beam-columns were tested with a 40 mm eccentricity at loading. The experimental results were then analyzed and compared with the theoretical ones, which were calculated with the recommendations of the Brazilian standard ABNT NBR 8800:2008 and the Eurocode 4, 2004. The experimental results, obtained were consistent with the theoretical predictions.
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Ahsan, Shainur. "Evaluation of Hybrid-Composite Beam for Use in Tide Mill Bridge." Thesis, Virginia Tech, 2012. http://hdl.handle.net/10919/35061.
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A test program for the Hybrid-Composite Beam (HCB) was conducted prior to its use for the replacement of a skewed, simply-supported bridge (Tide Mill Bridge). The HCB is an innovative combination of conventional materials and ideas in a structural beam. The beam consists of a concrete arch tied with prestressing strand that is placed within a Fiber-Reinforced Polymer (FRP) box. Behavior in individual HCBâ s and a three HCB-system was examined to determine the appropriateness of the current design methodology developed by John Hillman and the simplifying assumptions made within it. Such assumptions include strain compatibility and linear-elastic behavior. Three HCBâ s were tested at the structures laboratory at Virginia Tech. During individual beam tests, the predicted behavior of the FRP box and prestressing strand agreed with experimental results. The tests revealed the arch was susceptible to local bending and behaved far differently from predicted. Overall, the beams were shown to behave linearly. A final test was performed to apply the design live load to the system. Slight non-linear behavior was observed in the beams. Distribution factors for the system were also investigated and compared to AASHTO and Hillmanâ s model. AASHTO factors were conservative for exterior girders but unconservative for interior girders. Hillmanâ s factors were often conservative but were in agreement for the shear in the exterior girder. The current design procedure appeared to predict FRP and strand behavior well, but the behavior of the arch appeared to differ greatly from the other components of the HCB.Master of Science
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Ragon, Scott Alan. "Optimization of composite box-beam structures including effects of subcomponent interaction." Thesis, Virginia Tech, 1994. http://hdl.handle.net/10919/43336.
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Minimum mass designs are obtained for a simple box beam structure subject to bending, torque and combined bending/torque load cases. These designs are obtained subject to point strain and linear buckling constraints. The present work differs from previous efforts in that special attention is payed to including the effects of subcomponent panel interaction in the optimal design process. Two different approaches are used to impose the buckling constraints. When the global approach is used, buckling constraints are imposed on the global structure via a linear eigenvalue analysis. This approach allows the subcomponent panels to interact in a realistic manner. The results obtained using this approach are compared to results obtained using a traditional, less expensive approach, called the local approach.
When the local approach is used, in-plane loads are extracted from the global model and used to impose buckling constraints on each subcomponent panel individually. In the global cases, it is found that there can be significant interaction between skin, spar, and rib design variables. This coupling is weak or nonexistent in the local designs. It is determined that weight savings of up to 7% may be obtained by using the global approach instead of the local approach to design these structures.
Several of the designs obtained using the linear buckling analysis are subjected to a geometrically nonlinear analysis. For the designs which were subjected to bending loads, the innermost rib panel begins to collapse at less than half the intended design load and in a mode different from that predicted by linear analysis. The discrepancy between the predicted linear and nonlinear responses is attributed to the effects of the nonlinear rib crushing load, and the parameter which controls this rib collapse failure mode is shown to be the rib thickness. The rib collapse failure mode may be avoided by increasing the rib thickness above the value obtained from the (linear analysis based) optimizer. It is concluded that it would be necessary to include geometric nonlinearities in the design optimization process if the true optimum in this case were to be found.Master of Science
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Waldron, Christopher J. "Determination of the Design Parameters for the Route 601 Bridge: A Bridge Containing the Strongwell 36 inch Hybrid Composite Double Web Beam." Thesis, Virginia Tech, 2001. http://hdl.handle.net/10919/34414.
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The Route 601 Bridge spans 39 ft over Dickey Creek in Sugar Grove, VA and represents the first use of Strongwell's 36 in. double web beam (DWB) as the main load carrying members for a traffic bridge. The bridge was designed for AASHTO HS20-44 and AASHTO alternate military loading with a targeted deflection limit of L/800. For the preliminary design, conservative properties for the 36 in. DWB were assumed based on experience at Virginia Tech with Strongwell's 8 in. DWB used in the Tom's Creek Bridge. An elastic modulus (E) of 6,000 ksi and a shear stiffness (kGA) of 20,000 ksi-in2 were assumed and used with Timoshenko shear deformable beam theory to characterize the beams and determine the deflections.
This thesis details the experimental work conducted in conjunction with the design of the Route 601 Bridge, which had two goals. First, a deck-to-girder connection was tested to determine if a bolted connection could develop composite action between the girder and the deck. This connection was shown to provide a significant amount of composite action when used with the 8 in. DWB and a composite deck, but little or no composite action when used with the 36 in. DWB and a glue-laminated timber deck. Second, eleven 36 in. DWB's were tested to determine their stiffness properties (EI and kGA) to insure that these properties were above the values assumed in the preliminary design, and all the beams had stiffness properties that were close to or above the assumed values. The eleven beams were also proof tested to a moment equivalent to five times the service load moment to insure the safety of the Route 601 Bridge, and one beam was tested to failure to determine the failure mode and residual stiffness of the 36 in. DWB. Finally, based on these results eight beams were chosen for the Route 601 Bridge.Master of Science
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Wang, Qi. "Asymptotic Multiphysics Modeling of Composite Beams." DigitalCommons@USU, 2011. https://digitalcommons.usu.edu/etd/1066.
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A series of composite beam models are constructed for efficient high-fidelity beam analysis based on the variational-asymptotic method (VAM). Without invoking any a priori kinematic assumptions, the original three-dimensional, geometrically nonlinear beam problem is rigorously split into a two-dimensional cross-sectional analysis and a one-dimensional global beam analysis, taking advantage of the geometric small parameter that is an inherent property of the structure.
The thermal problem of composite beams is studied first. According to the quasisteady theory of thermoelasticity, two beam models are proposed: one for heat conduction analysis and the other for thermoelastic analysis. For heat conduction analysis, two different types of thermal loads are modeled: with and without prescribed temperatures over the crosssections. Then a thermoelastic beam model is constructed under the previously solved thermal field. This model is also extended for composite materials, which removed the restriction on temperature variations and added the dependence of material properties with respect to temperature based on Kovalenoko’s small-strain thermoelasticity theory.
Next the VAM is applied to model the multiphysics behavior of beam structure. A multiphysics beam model is proposed to capture the piezoelectric, piezomagnetic, pyroelectric, pyromagnetic, and hygrothermal effects. For the zeroth-order approximation, the classical models are in the form of Euler-Bernoulli beam theory. In the refined theory, generalized Timoshenko models have been developed, including two transverse shear strain measures. In order to avoid ill-conditioned matrices, a scaling method for multiphysics modeling is also presented. Three-dimensional field quantities are recovered from the one-dimensional variables obtained from the global beam analysis.
A number of numerical examples of different beams are given to demonstrate the application and accuracy of the present theory. Excellent agreements between the results obtained by the current models and those obtained by three-dimensional finite element analysis, analytical solutions, and those available in the literature can be observed for all the cross-sectional variables. The present beam theory has been implemented into the computer program VABS (Variational Asymptotic Beam Sectional Analysis).
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Mwita, Wambura Mwiryenyi. "Development and testing an intelligent hybrid polymeric composite beam with healing ability embedded with Ni-Ti shape memory alloy." Thesis, Cape Peninsula University of Technology, 2010. http://hdl.handle.net/20.500.11838/1251.
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Thesis (MTech (Mechanical Engineering))--Cape Peninsula University of Technology, 2010.Hybrid polymeric composites (HPC) are widely used for the design of aerospace, automobile and civil engineering structures. One of the major challenges posed by these materials and structures is their brittle nature. When subjected to impact and dynamic loads, the polymeric composite structures undergo micro cracking. The cracks coalesce, propagate and can lead to catastrophic failure of the material and structures. In this thesis, an intelligent hybrid polymeric composite (IHPC) beam with healing ability was developed and tested. The IHPC beam developed consisted of a 3% prestrained 1mm diameter Ni-Ti shape memory alloy (SMA) wire actuator embedded in the polymeric host matrix. The function of the embedded Ni-Ti shape memory alloy was to enhance intelligence and healing ability to the IHPC beam. Upon electric current resistance heating, the Ni-Ti SMA actuator responds by contracting as a result of detwinned martensite → austenite phase transformation. Contraction of the SMA in the IHPC beam was utilized to stiffen and enhance healing by retarding crack growth and recovery of the strain induced in the loaded IHPC beam. This can result to increase of the flexural stiffness EI (defined as the product of the Young’s Modulus E of the material and the moment of inertia I of the geometry of the beam) and mode I fracture stress intensity factor KIC of the IHPC beam. One (1) mm diameter Ni-Ti SMA wire was used in the experimental work in this thesis. The wire was cut into 35 pieces, 200 mm long each. Ni-Ti SMA wires were heated in the furnace to a temperature of 250ºC for ten (10) hours then were left to cool in the ambient air. The heat treatment was aimed to release any residual stress and to stabilize the austenite start (AS) and austenite finish (Af) transformation temperatures of the Ni-Ti SMA. After heat treatment, the Ni-Ti SMA wires were prestrained by 3% (based on a gauge length of 150mm) on a tensile testing machine. Prestraining of the Ni-Ti SMA wires was aimed to induce detwinned martensite volume fraction in them hence increasing the transformation strain and recovery force of the Ni-Ti SMA actuator. Intelligent hybrid polymeric composite (IHPC) beams and polymeric virgin (PV) beams, all of dimensions 150mmx25mmx10mm were manufactured by casting 60D polyurethane thermosetting epoxy resin in a silicon mould. transformation strain and recovery force of the Ni-Ti SMA actuator.
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Lim, Hyungsuk. "Performance of strand-based wood composite post-and-beam shear wall system." Thesis, University of British Columbia, 2016. http://hdl.handle.net/2429/56823.
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This dissertation proposes a strand-based wood composite product to be utilized as the vertical members of post-and-beam (P&B) shear walls. Since the shear wall performance is largely governed by connection systems holding the wall components together, the research focuses on the structural behaviour of two key connection types: nail and hold-down connections. The experimental studies were designed to evaluate the effects of orthogonal properties, such as vertical density profile of the strand-based product, on the connection performance. Static load tests were conducted following ASTM standards and Japanese HOWTEC connection performance guidelines. The test results showed that the connections with fasteners mounted on the face-side of the composite product outperform the ones with fasteners mounted on the product’s edge-side. Subsequently, full-scale shear wall tests were conducted on three P&B wall types to study the effect of the fastener driving direction on the wall performance. The test results confirmed that the shear walls with face-driven nails outperforms the ones with edge-driven nails in terms of load carrying capacity.
A detailed mechanics-based finite-element connection model RHYST was also developed to predict the load-displacement relationship of a nail connection. It was developed based on an existing connection model HYST which idealizes a dowel-type connector driven into a wood medium as an elasto-plastic beam embedded in a nonlinear foundation that only acts in compression. RHYST assumes that the lateral response of the wood medium does not decrease at any compressive displacement. The presented model takes into account the contribution of the fastener’s vertical displacements on the response of the foundation. The simulation results of RHYST agreed well with the reversed-cyclic nail connection test results in terms of load carrying capacity and energy dissipation. The model is also able to simulate strength and stiffness degradation between the repeated loading cycles. Moreover, the applicability of RHYST was confirmed by incorporating it as a subroutine in a finite-element shear wall model WALL2D. The simulation results of WALL2D with RHYST showed a good agreement with the wall test results.Forestry, Faculty of
Graduate
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Al-Jabri, Khalifa Saif. "The behaviour of steel and composite beam-to-column connections in fire." Thesis, University of Sheffield, 1999. http://etheses.whiterose.ac.uk/2997/.
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Recent fire tests on the Cardington full-scale test frame and observations from real fires have demonstrated the significance of connections in fire, when they can have beneficial effects on the survival time of the structure. The lack of experimental data on the behaviour of steel and composite connections in fire means that this is insufficiently addressed in current design codes and also limits the effective use of numerical models. However, recent experimental tests on small-scale specimens have shown that it is possible to derive accurately the moment-rotation relationships at elevated temperature and have established the principles by which this could be achieved. In order to extend the scope to include further parameters, five series of tests have been carried out in a portable connection furnace at the Building Research Establishment. The test series includes flush and flexible end-plate bare-steel connections, and flexible end-plate composite connections. The testing procedure and the resulting behaviour are described. The fire test temperature profiles across the connections are detailed and the connection failure mechanisms are discussed. From the test results, moment-rotation- temperature curves for different connection types are derived. The degradation of connection characteristics is compared with that of structural steel. The experimental behaviour is also compared with the results obtained from an existing finite element analysis developed to model connection response in fire conditions. The experimentally derived connection characteristics have been incorporated within a parametric study of a typical sub-frame, to study the effect of connection type, end-plate thickness, concrete strength, load ratio, and connection temperature. Analysis is extended to a three-dimensional sub-frame. The patterns of behaviour observed in the connection tests is compared with that of the connections in the large-scale fire tests on the composite building at BRE's Cardington laboratory. Based on knowledge about the behaviour of connections at elevated temperature, a component-based model is developed for the elevated temperature response for flexible end-plate connections, both as bare-steel and composite. This is based on the response of constitutive parts of connection. The model is easy to use, and capable of modelling the entire non-linear range of connection behaviour. The predicted response is compared with that recorded experimentally.
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Hsieh, Kunlin. "Numerical Modeling and Analysis of Composite Beam Structures Subjected to Torsional Loading." Thesis, Virginia Tech, 2007. http://hdl.handle.net/10919/32580.
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Torsion of cylindrical shafts has long been a basic subject in the classical theory of elasticity. In 1998 Swanson proposed a theoretical solution for the torsion problem of laminated composites. He adopted the traditional formulation of the torsion problem based on Saint Venantâ s torsion theory. The eigenfunction expansion method was employed to solve the formulated problem. The analytical method is proposed in this study enabling one to solve the torsion problem of laminated composite beams. Instead of following the classical Saint Venant theory formulation, the notion of effective elastic constant is utilized. This approach uses the concept of elastic constants, and in this context the three-dimensional non-homogeneous orthotropic laminate is replaced by an equivalent homogeneous orthotropic material. By adopting the assumptions of constant stress and constant strain, the effective shear moduli of the composite laminates are then derived. Upon obtaining the shear moduli of the equivalent homogeneous material, the effective torsional rigidity of the laminated composite rods can be determined by employing the theory developed by Lekhnitskii in 1963. Finally, the predicted results based on the present analytical approach are compared with those by the finite element, the finite difference method and Swansonâ s results.Master of Science
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Tudela, Mark A. "Impact response of a laminated beam on an elastic foundation." Diss., Georgia Institute of Technology, 2002. http://hdl.handle.net/1853/17880.
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Hemanshu. "Vibration Analysis of Composite Beam." Thesis, 2013. http://ethesis.nitrkl.ac.in/5009/1/VIBRATION_ANALYSIS_OF_COMPOSITE_BEAM..pdf.
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Beams are the basic structural components. When they are made laminated composites their strength to weight ratio increases. They can be used for different application just by changing the stacking sequence in the laminate with the same weight and dimensions. So this requires a complete analysis of laminated composite beams. They are used in a variety of engineering applications such as airplane wings, helicopter blades, Sports equipment’s, medical instruments and turbine blades. An important element in the dynamic analysis of composite beams is the computation of their natural frequencies and mode shapes. It is important because composite beam structures often operate in complex environmental conditions and are frequently exposed to a variety of dynamic excitations. In this research work first order shear deformation theory is used for vibration analysis of composite beams. A dynamic analysis is carried out which involves finding of natural frequencies and mode shapes for different L/H ratios and different stacking sequences. Finally the non-dimensional natural frequencies of the beam are calculated by using MATLAB and ANSYS model of corresponding composite beam.
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Dorsey, Daniel John. "Development of neutron beam analytical techniques for characterization of carbon fiber composite materials." Thesis, 2003. http://wwwlib.umi.com/cr/utexas/fullcit?p3120285.
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Lo, Chiao, and 羅喬. "Composite Beam Design - Theory and Practice." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/58130184485773587302.
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碩士國立中興大學
土木工程學系
87
Composite beams have been widely used in both building and bridge structures. The specified composite beams in this research consist of w-shaped rolled shapes, concrete, formed steel decks, and shear connectors. The current AISC manuals provide two specifications for analysis and design, which include the ASD (Allowable Stress Design) and the LRFD (Load and Resistance Factor Design). The AISC/ASD specifications provide engineers with the tools for analyzing the required section properties, however, this is not enough for the general practicing engineers, especially the fresh engineers. The study gives the derivations of the formulas listed in the specifications and show how the allowable moments of various composite beams are obtained. The comparison between the theoretical and the tabled values of the manual is also conducted. The AISC/LRFD provides only the design moment strength and the low bound moment of inertia of various composite sections. The research shows how the formulas are derived and the difference between the theoretical and the listed values. The study surveys the difference of two AISC specifications and compares various composite sections in the two AISC manuals. The final conclusions and suggestions are drawn and hope that they will raise the analysis and design at a high lever for the practicing engineers.
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Kumar, Nikhil. "Vibrational Analysis Of Laminated Composite Beam." Thesis, 2011. http://ethesis.nitrkl.ac.in/2219/1/final_report.pdf.
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A composite beam consists of laminate consisting of more than one lamina bonded together through their thickness. Thicknesses of Lamina are of order 0.005 inch (0.125mm), implying that to take realistic loads several laminae will be required. For a typical unidirectional lamina the mechanical properties are severely limited in the transverse direction. Stacking several unidirectional layers, may lead to an optimum laminate for unidirectional loads. However, this would not be desirable for complex loading and stiffness requirements,. One can overcome this problem by making a laminate with layers stacked at different angles to withstand different loading and stiffness requirements. Usually more than one lamina are bonded together through their thickness to get real structure. Each layer can be identified, its material, its angle of orientation with respect to a reference axis and by location in the laminate.
Reduced stiffness matrix was obtained by using properties of composite material. These properties are Longitudinal elastic modulus , Transverse elastic modulus , Major poisons ratio and Shear modulus . Using these properties composite compliance matrix was obtained . Inverse of compliance matrix was taken and reduced stiffness matrix was obtained . Then reduced stiffness matrix for each and every layer was calculated . Reduced stiffness matrix for each and every layer was calculated taking in consideration angles of the fiber in lamina .
Mid plane symmetry was taken and position of each layer was calculated with respect to mid plane .D11 matrix was determine by formula using relative position of layer from mid plane and reduced stiffness matrix of all lamina ( effect of angle of fiber was included ) . Density of composite material was obtained by using densities of each material and there volume composition. Value of natural frequency in rad/sec and per sec was obtain by using formulation for finding frequency of composite material . Frequency was obtained for all the supports i.e simple –simple , simple – clamped , clamped –clamped and clamped –free and for first three mode of vibration . Glass/epoxy , graphite /epoxy and boron epoxy composites were used to obtain tabulation for natural frequency in hertz . Comparison of frequency for these composite , frequency of composite under different mode condition were done for these composites and required histogram was plotted . Taking beam as euler beam , equation of euler beam was considered and was solved for simple –simple case taking in consideration boundary condition of simple – simple support condition i.e displacement at support and bending moment at support is equal to zero .
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Tsung-Pin, Hung, and 洪宗彬. "Finite Element Analysis for Laminated Composite Beam." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/67982289202915513452.
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碩士中國文化大學
材料科學與製造研究所
89
Based on the analysis of the laminated I beam, the laminated T beam has been analyzed by using composite beam theory and lamination theory. One-dimensional and two-dimensional approaches are applied to derive the theoretical formulas of the bending stiffness and the bending stress of the laminated T beam. Under the Kirchoff-Love deformation assumption, the one-dimensional approach only considers the uniaxial strain, while the two-dimensional approach takes into account 2-D plane stress state. Furthermore, the laminated T beam has been treated as the combination of two thin laminate plates of the web and the flange for the two-dimensional approach. Then, the neutral axis is determined by the condition of the zero axial force and the effective stiffness can be deduced from the moment-curvature relation. Finally, the stress and strain in each ply can be calculated. The MSC/NASTRAN for window is applied to perform the finite element analysis. The AS4/3501-6 carbon/epoxy I and T beam with a length of 20in and the web height of 0.75in as well as the flange width of 0.5in are simply supported and subjected to a uniformly distributed load. Two cases of the symmetric flange lay-up of and the nonsymmetric flange lay-up of with the web layup of are used for case studies. The comparisons of the theoretical and FEM results have shown that: 1.The accuracy of and the limitation of the usage of the theoretical formulas have been verified by the finite element analysis. 2.FEA results will convergence as I beam elements greater than 1200 elements/in, while T beam elements greater than 800 elements/in. 3.As the aspect ratio (length/height) is greater than 15, the formulas can provide the acceptable accuracy. 4.As the one-dimensional approach only considers the uniaxial strain, the accuracy of the one-dimensional approach is much less than the two-dimensional approach as compared to the FEM results. 5.Because 0°plies sustain most bending stress and placing them to the outer surface of the flange, the bending stiffness will increase without changing materials.
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Chien-Chung, Chen, and 陳建中. "Flexural Behavior of Steel-Encased Composite Beam." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/42556988911180339428.
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碩士國立臺灣科技大學
營建工程系
88
In this research,16 large size SRC beams were fabricated and tested under monotonic load to investigate the flexural behavior of SRC beams. Test results show that : (1)the horizontal shear strength could influence composite action; (2)the shear studs are beneficial for the horizontal shear strength; (3)the behavior of SRC beams is similar to the behavior of RC (Reinfored Concrete) beams; (4)the ductility of SRC beams is influenced by the ratio of the depth of steel H-shape to the depth of the section; (5)it is more accurate to approach the flexural strength of SRC beams by using the ACI method.
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Lawson, M., E. S. Aggelopoulos, and Dennis Lam. "Test on 15m Span Composite Cellular Beam." 2014. http://hdl.handle.net/10454/10305.
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noCellular beams are the preferred form of long span construction in multi-storey buildings. For efficient design of composite cellular beams, asymmetric sections are often manufactured in which the bottom flange is larger than the top flange. A further innovation is in the use of 80mm deep deck profiles which allows beam spacing to be increased to 4.5m, and so the effective slab width acting compositely with the long span beams is also increased. The values for shear connector (stud) resistance given in Eurocode 4 (EN 1994-1-1), when used in combination with these modern decking profiles, have led to problems in achieving the minimum degree of shear connection for composite beams in comparison to the former BS 5950-3. For secondary beams, the number of shear connectors that can be accommodated in a span is limited by the spacing of the deck ribs (typically 300mm for deep trapezoidal profiles), and it is found that even for pairs of shear connectors per deck rib, it is impossible to satisfy the shear connection rules in Eurocode 4 for long span asymmetric beams. SCI, with support from the Research Fund for Coal and Steel, is on the way to resolving this problem in design to Eurocode 4, and has completed a test on a 15.3m composite cellular beam at the University of Bradford. This is believed to be the longest composite cellular beam test ever carried out. The test was part-sponsored by ASD Westok.
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Th, Abdul Khader Shahadaf. "Vibration analysis Of composite beam with crack." Thesis, 2013. http://ethesis.nitrkl.ac.in/5011/1/VIBRATION_ANALYSIS_OF_COMPOSITE_BEAM_WITH_CRACK.pdf.
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Composite beams and beam like elements are principal constituents of many structures and used widely in high speed machinery, aircraft and light weight structures. Crack is a damage that often occurs on members of structures and may cause serious failure of the structures. The influence of cracks on dynamic characteristics like natural frequencies, modes of vibration of structures has been the subject of many investigations. However, the parametric studies like effect of geometry, crack location and support conditions on natural frequencies of composite beam are scarce in literature. In the present work, a numerical study using finite element is performed to investigate the free vibration response of composite beams. The finite element software ANSYS is used to simulate the free vibrations. A variety of parametric studies are carried out to see the effects of various changes in the laminate parameters on the natural frequencies. The parameters investigated include the effects of fiber orientation, the location of cracks relative to the restricted end, depth of cracks, volume fraction of fibers, length of beam and support conditions. The study shows that the highest difference in frequencies occur when the value of the fiber orientation equal to zero degree. The increase of the beam length results in a decrease in the natural frequencies of the composite beam and also shows that an increase of the depth of the cracks leads to a decrease in the values of natural frequencies.
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Wang, Ren-You, and 王仁佑. "Composite Sector Beam and Switched-Beam Single-Conductor Leaky-Wave Antenna Arrays." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/68526137538948473625.
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碩士國立交通大學
電信工程系所
97
Ordinary leaky wave antenna has the advantages of broadband, high gain, and high directivity. Also, most of them have the function of frequency scanning. However, since single conductor leaky wave antenna is without actual ground, the radiation pattern is fixed in the end-fire direction. Thus, by making use of this characteristic, we arrange a fan-shaped antenna array, which results in sector radiation pattern while preserving the strengths of broadband, high gain, and end-fire radiation pattern. Finally, we present an efficient method to synthesize radiation patterns based on the antenna array theory. By changing the radius and spacing angle of fan-shaped antenna array appropriately, we can mold and obtain the desired half-power beamwidth of this antenna. Generally, the beam of beam-switched smart antenna does not change with frequency, which fits the nature of the mainbeam of single conductor leaky wave antenna. Therefore, we design two sets of smart antenna. Both are formed with four identical single conductor leaky wave fan-shaped antenna arrays placed in four different directions. The half-power beamwidth of the first and the second antenna array are 23°and 50° respectively. After adding a pair of SP4T switch, which we designed, we are able to switch the main beam of each array, which will allow the first and the second antenna arrays to cover a range of angle of 92° and 200° respectively. Related statistics, stimulation and the values of measurement will be presented.
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Lam, Dennis, and F. Fu. "Modelling of semi-rigid composite beam-column connections with precast hollowcore slabs." 2005. http://hdl.handle.net/10454/5551.
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NoThe chapter describes the ongoing work on modeling the semi-rigid composite beam-column connections of composite beams with precast hollow core slabs. Using the finite element (FE) software ABAQUS, a three-dimensional (3D) model of a composite joint is set up. The technique of simulating bolt force, endplate, concrete elements, reinforcement, and shear connectors, and the interaction between slabs and steel beams is presented in the chapter. Preliminary results on the steel joint and simplify composite joint are also presented in the chapter. FE model for the bare steel joints and the simplified composite joints are presented, and the result of the simplified composite model showed good agreement with the experimental result but with lower joint stiffness. Further work on the full finite element model of composite joints is still going on.