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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.
81

Avaliação da delaminação e da resistência da linha de cola de elementos de MLC com base no projeto de revisão da norma ABNT NBR 7190:2013 considerando madeiras de reflorestamento tratadas com CCA e sem tratamento preservativo /

Bianchi, Natália Andrade January 2020 (has links)
Orientador: Julio Cesar Molina / Resumo: A Madeira Laminada Colada (MLC) é uma alternativa promissora no mercado brasileiro de construção, as indústrias vêm buscando alternativas que melhorem a qualidade de seus produtos seja através das espécies de madeira utilizadas, tipo de adesivo ou processo de fabricação. Este estudo avaliou os métodos de ensaio de delaminação e resistência da linha de cola propostos pelo projeto de revisão da norma brasileira de madeiras ABNT NBR 7190:1997. Foram considerados os métodos de ensaio ABNT NBR PN 02:126.10-001-5 e ABNT NBR ISO PN 02:126.10-001-3. Foram utilizados dois gêneros de madeiras (Pinus e Eucalipto), com e sem tratamento preservativo das lamelas com CCA e três tipos de adesivos (poliuretanas mono e bicomponente e resorcinol-formaldeído). Para os ensaios de delaminação e resistência da linha de cola, foram confeccionados os dispositivos necessários (autoclave e dispositivo para ensaio de cisalhamento da linha de cola). Os resultados de delaminação revelam que os valores médios obtidos para as combinações ERS (Eucalipto - Resina resorcinol-formaldeído - In natura), EBS (Eucalipto - Resina poliuretana bicomponente - In natura) e PRS (Pinus - Resina resorcinol-formaldeído - In natura) apresentaram valores dentro do aceitável de 4% pelo projeto de norma PN 02:126.10-0001- 5. Os resultados da análise estatística entre as linhas de cola mostraram que há diferença significativa entre as resistências médias ao cisalhamento. De modo geral, as combinações empregando Eucalipto apresen... (Resumo completo, clicar acesso eletrônico abaixo) / Mestre
82

Limträstomme till hallbyggnader : Utformning och dimensionering av momentstyva ramhörn och 3D-modell framtagning / Glulam frames for industrial buildings : Configuration and sizing of moment resisting eaves and 3D-model generation

Johansson, Anton, Simonov Lopez, Maxim January 2012 (has links)
Industrial buildings are increasing all over Sweden. Farmers are building new modern facilities and the government chooses to build new halls to invest i youth sports. Glulam is the most common framework but there are limitations because of the transport. Therefore, there is a need to develop new solutions to increase the use of glulam. The maximum torque in the eaves was found in the frame with a roof pitch of 18 degrees and a wingspan of 25 meters. Using hand calculations according to Eurocode and comparison with the computer software StatCon, the maximum torque, shear force and utilization rate is calculated. Based on the maximum torque, of 973,86 kNm (calculated as 1000 kNm), the maximum compressive force is found in the eaves storage. The area is determined to 0.116m2 and the eaves are formed with 7 lamellae glued to the inside of the frame to relocate the support surface so that cutting of the laminated timber should be as simple as possible. The relocation of the storage is also needed for the required number of WR-T screws to fit on top of the frame. The screws are dimensioned according to previously calculated traction force in the eaves and to the transmission between the screws and the glulam. The transmission forces were found in a product brochure by SFS intec. Two different screw sizes is tested and deployed by distance according to Eurocode. -          WR-T-9x400                  Number: 332 pieces/frame   Cost: 15 897 skr/frame -          WR-T-13x700               Number: 136 pieces/frame   Cost: 22 927 skr/frame Calculations on the new attachment method show that it is possible to construct moment resisting eaves. In an economic comparison between the screws, it appears that WR-T-9x400 was the cheapest regardless of the length or span on the chosen building. The design of the glulam frame system in 3D is based on the calculations and definitions. The models are developed in the software Revit in stages according to the desired dimensions and local conditions in order to show the client at the tender negotiations. / Byggandet av hallbyggnader ökar runt om i Sverige. Lantbruk bygger nya moderna anläggningar och staten väljer att bygga nya hallar för att satsa på ungdomsidrotten. Limträ är ett mycket vanligt stommaterial men det finns begräsningar av limträmöjligheterna som styrs av transporten. Därför finns det behov av att utreda nya lösningar för att kunna öka användandet av limträ. Av de undersökta ramarna beräknades det maximala momentet i ramhörnet där taklutningen var 18 grader och spännvidden 25 meter. Med hjälp av handberäkningar enligt Eurocode och jämförelser med dataprogrammet StatCon togs maximalt moment, tvärkrafter, normalkrafter och utnyttjandegrader ut. Utifrån det maximala momentet, 973,86 kNm (räknas som 1000 kNm) beräknas tryckkraften vid ramhörnsupplaget som dimensionerar upplagsarean. Arean bestämdes till 0.116m2 och ramhörnet utformas med 7 pålimmade lameller på insidan av rambenet samt på undersidan av överramen för att förskjuta upplagsytan så att sågningen av limträet ska vara så enkelt och ekonomiskt som möjligt. Förskjutningen krävs även för att erfordrat antal WR-T skruvar ska få plats på ovansidan av rambenet. Skruvarna dimensioneras efter tidigare beräknad dragkraft i ramhörnet och skruvarnas kraftöverföring till limträet bestäms enligt underlag från SFS intec. Två olika skruvdimensioner testas och placeras ut efter avstånd enligt Eurocode:  - WR-T-9x400 Antal: 332 st/ram Kostnad: 15 897 kr/ram - WR-T-13x700 Antal: 136 st/ram Kostnad: 22 927 kr/ram  Beräkningar på den nya infästningsmetoden visar att det är möjligt att konstruera momentstyva ramhörn som kan monteras på plats med skruvmontage. Vid en ekonomisk jämförelse mellan skruvarna visar det sig att WR-T-9x400 skruven blir billigast oavsett vilken längd eller spännvidd man väljer på byggnaden. Utifrån beräkningar och avgränsningar utformas 3D-modeller av limträstomsystemet i dataprogrammet Revit. Modellerna tas fram stegvis efter önskade dimensioner och lokala förutsättningar för att kunna visa beställaren vid offerförhandlingarna.
83

Parametric design and optimization of steel and timber truss structures : Development of a workflow for design and optimization processes in Grasshopper 3D environment

WELDEGIORGIS, FILMON, DHUNGANA, ANUP RAJ January 2020 (has links)
The demand for complex structures and the urge to perform more detailed structural analyses in an early stage of the project design phase has increased the use of parametric design in the construction sector, especially among architects and structural engineers. Also, an increasing demand for sustainable structures is creating pressure on engineers and architects to design optimized structures that consume as little resources as possible. Keeping these demands in mind, this thesis tries to uncover the benefits of parametric design and optimization by applying these processes to industrial roof truss structures.The primary objective of the thesis is to investigate the feasibility and reliability of parametric design and optimization processes in real-life designs. For this purpose, a parametric algorithm has been developed in the visual programming software Grasshopper 3D. The workflow performs structural analysis and design verification on a parametric FE-model using the FEA software for parametric engineering, Karamba 3D in combination with Python where standards for design verification were scripted. These procedures were developed to be applied on both steel and timber truss structures. The workflow then performs a constrained cross-sectional and geometrical optimization of the truss structures. For the optimization process, the plug-in Galapagos have been used which uses evolutionary and simulated annealing techniques.After analyses of different cases and on comparison of the results from the model response verification, the resulting models showed that the workflow and analysis procedure was capable of obtaining a solution that is more effective and as reliable as the traditional structural analysis procedures and thus can be used for real case. When used during preliminary design, the parametric design procedure displayed great potential in saving time, thus saving resources and cost which paves a promising path for implementations in this sector.
84

Ett gestaltningsförslag på ett flerbostadshus i trå : Stubben i Rosenlundsparken / A proposal of a residential building in wood : Stubben in Rosenlundsparken

Holmstjerna, Elin, Haraldsson, Erika January 2019 (has links)
Examensarbetet behandlar trä som byggnadsmaterial. I arbetet ingår en rapport med förklarande illustrationer samt framtagning av programhandlingar för ett bostadsprojekt. Byggbranschen står idag för en hög miljöbelastning där den största bidragande faktorn är materialproduktionen. Trots att trä är det enda koldioxidneutrala konstruktionsmaterialet byggs få flerbostadshus med trä som bärande stomme. Det råder brist på kunskap och erfarenhet inom träbyggnadsteknik av anledningen att en tidigare lagstiftning förbjöd byggnader över två våningar med trästomme. Studien har fördjupat sig i möjligheterna när det gäller lång spännvidd, konstruktionshöjd och arkitektonisk karaktär men även kraven för ljud och brand har styrt utformningen. Till en början förväntades trä ge upphov till en del begränsningar, främst gällande brand och akustik, men dessa kan till stor del lösas genom kompletteringar och noggrann projektering. Trä har många positiva egenskaper som hög hållfasthet, bra bärförmåga vid brand, bra värmeisoleringsförmåga samt att det ger ett bra inomhusklimat, vilket kan nyttjas i en byggnad. Fastigheten som valdes för projektet ligger i Rosenlundsparken på Södermalm i Stockholm. På platsen var det gynnsamt att bygga i trä på grund av bland annat dåliga markförhållanden. Studien har resulterat i en byggnad på 9 våningar, där den bärande stommen är helt utförd i trä. Stommen är uppbyggd av pelarbalksystem i entréplan och KL-trä på de resterande våningarna. Ett ribb-bjälklag har använts, som är en kombination av KL-trä och limträ. Resultatet visade att om tjocka bjälklag implementeras kan flerbostadshus med långa spännvidder uppföras, med en högre byggnadshöjd som följd. Långa spännvidder ger en frihet när det gäller att utforma planlösningar. Trä är ett flexibelt material vilket ger möjlighet till frihet i form. Träets naturliga karaktär ger en positiv effekt på människor och är estetiskt tilltalande. Byggnaden har böjda former vilket bidrar med kontrast till det befintliga stadsrummet. Fasaden är utförd i trä och även interiört är det synligt trä i stor utsträckning. / The thesis is about wood as a building material. The work contains a report with explanatory illustrations and a project planning document for a residential. The building sector has a big impact on the climate, where the biggest contribution is the manufacturing of materials. Wood is the only material that is carbon oxide neutral, but still a small amount of the high apartment buildings is constructed with a wooden frame. The reason behind this is that a former law prevented wooden buildings higher than two floors and therefore there is a lack of knowledge and experience regarding wooden building technique. Wood has many positive qualities, which can be of advantage in a building. Such as a good load bearing capacity during a fire, good strength, good thermal conductivity, and it provides a healthy internal climate. There are also limitations with wooden constructions regarding fire and sound, but this can often be solved with supplements and thorough planning. This study examined the possibilities regarding span, height, and architecture. Additionally, sound- and fire conditions had an impact on the design. The project resulted in a long free span in consequent of a thick slab and therefore the building height increases. The property that was chosen for the project is located to Rosenlundsparken at Södermalm in Stockholm. The condition of the ground was not optimal to build on, because it consists of clay. But an advantage with a wooden construction it that it is light, which reduces the land work. This study resulted in a 9-floor high building where the frame is completely in wood. The frame is constructed with a column and beam system in the entrance floor and CLT walls on the other floors. A ribbed slab was chosen, which is a combination of CLT and glulam. The result showed that if thick slabs are implemented, residential buildings with long free span can be built and with a higher building height as a consequence. A long free span gives freedom when making floor plans. Furthermore, the wood offers flexibility, which makes different shapes possible. The building has round shapes which makes a contrast to the existing cityscape. Moreover, the woods natural character has a positive effect on humans and is aesthetically appealing. Wood is used as a cladding to the extent possible both interior and exterior.
85

Skillnaden i koldioxidutsläpp mellan limträ och stål : En studie som jämför två olika stommaterial / A study that compares two different frame materials

Dicksen, Jesper January 2021 (has links)
Idag görs livscykelanalyser (LCA) för att identifiera de byggkomponenter somorsakar stora koldioxidutsläpp i byggbranschen.Syftet med denna studie är att med hjälp av livscykelanalysverktyget One ClickLCA jämföra hur stora koldioxidutsläpp som bildas av materialen i enlimträstomme, som tillhör en inomhusarena jämfört med materialen i en fiktivstålstomme, som är dimensionerad för att klara samma laster och funktion somlimträstommen. Detta görs i syfte att lyfta fram skillnaderna mellankoldioxidutsläppen i produktskedet (A1-A3) mellan en limträstomme och enstålstomme.En konstruktör har konstruerat stålstommen för jämförelsen. Konstruktören togfram dimensionerna och byggmaterialen, men stålstommen blev inte tillräckligtgenomarbetad och projekterad för att jämförelsen skulle kunna göras direkt.I One Click LCA behövs mängderna och byggkomponenterna för båda stommarnaför att kunna göra fullständiga livscykelanalyser. Med mängder menas volymeroch vikter för byggkomponenterna. I studien saknades från början mängder förvissa av byggkomponenterna och en del av syftet blev därför att ta fram allamängder för stommarna. För att få rätt mängder i studien användes bland annat tvåprogram, Bluebeam och Excel. Med dessa program togs längdmåtten för olikabyggkomponenter från ritningar. Tillsammans med de övriga uppgifterna ombyggkomponenterna kunde mängderna sedan tas fram.I One Click LCA behöver resurser väljas. Dessa kan vara kopplade till specifikabyggkomponenter och innehåller data om hur stora koldioxidutsläpp sombyggkomponenter orsakar. Med byggkomponenter och mängder som grund valdessedan resurser i One Click LCA. När resurser väljs räknar programmet ut hur storakoldioxidutsläpp som bildas i produktskedet (A1-A3) för byggkomponenterna.Med mängder och resurser kunde två resultat erhållas i programvaran. Resultatetvisar att 55 ton koldioxid bildas av limträstommen och 779,9 ton koldioxid bildasav stålstommen. I stålstommen är det fackverken som orsakar mestkoldioxidutsläpp och i limträstommen är balkarna i högdelen av inomhusarenansom orsakar mest koldioxidutsläpp. / Today, life-cycle assessment (LCA) are performed to identify the buildingcomponents that cause large carbon dioxide emissions in the construction industry.The purpose of this study is to use the life-cycle assessment tool One Click LCA tocompare how large carbon dioxide emissions are formed by the materials in aglulam frame, which belongs to an indoor arena compared to the materials in afictitious steel frame, which is dimensioned to withstand the same loads andfunction as the glulam frame. This is done in order to highlight the differencesbetween the carbon dioxide emissions in the product phase (A1-A3) between aglulam frame and a steel frame.A designer has designed the steel frame for comparison. The designer producedthe dimensions and building materials, but the steel frame was not sufficientlyworked out and projected for the comparison to be made directly.In One Click LCA, the quantities and building components for both frames areneeded to be able to make complete life-cycle assessment. By quantities is meantvolumes and weights for the building components. The study initially lackedquantities for some of the building components and part of the purpose wastherefore to produce all quantities for the frames. To get the right amounts in thestudy, two programs were used, Bluebeam and Excel. With these programs, thelength measurements for different building components were taken from drawings.Together with the other information about the building components, the quantitiescould then be produced.In One Click LCA, resources need to be selected. These can be linked to specificbuilding components and contain data on how large carbon dioxide emissions thatbuilding components cause. Based on building components and quantities,resources were then selected in One Click LCA. When resources are selected, theprogram calculates how large carbon dioxide emissions are formed in the productphase (A1-A3) for the building components. With quantities and resources, tworesults could be obtained in the software. The results show that 55 tonnes ofcarbon dioxide are formed by the glulam frame and 779.9 tonnes of carbon dioxideare formed by the steel frame. In the steel frame, it is the trusses that cause themost carbon dioxide emissions and in the glulam frame, the beams in the upperpart of the indoor arena cause the most carbon dioxide emissions.
86

Convergence: A New Future for the Samuel Madden Homes

Tran, Tram Anh Teresa 02 July 2019 (has links)
Housing in prosperous American cities is becoming increasingly expensive, forcing many municipal governments to re-evaluate how they will continue to serve lower-income residents and ensure equitable access to housing and resources. In the City of Alexandria, the Alexandria Re-Development and Housing Authority (ARHA) has worked in recent years to partner with private developers to convert its existing stock of low-density, designated-affordable housing into more dense, mixed-income communities. This is possible because many of its existing communities sit on land in now-prime locations where the City currently allows the most density, as well as bonus density through a variety of mechanisms. While these projects have succeeded to some extent, the City is unfortunately still seeing a rapid rise in rents accompanied by a rapid decrease in available affordable housing of all types, in both privately-developed and publicly-subsidized communities. Increasing income disparity is also simultaneously driving lower-income to middle-class residents to suburban and exurban sites where limited access to municipal resources and public transportation can be highly detrimental to quality of life. While additional density is the knee-jerk response to many of affordability's challenges, often the resulting built solutions seem incomplete – achieving the basic goal of housing more residents, but failing to build thriving and diverse communities that connect people the way previous communities may have. After all, the pragmatics of building generally point towards maximizing square footage, monetary return, and speed of delivery by using conventional and commonly-accepted solutions, with less energy given to resident outcomes, and how people might be affected by the change to their living environments and communities. As Jan Gehl and Jane Jacobs examined in Cities for People and The Death and Life of Great American Cities respectively, simple pragmatics do not make for livable environments. A truly humanist approach to design for living in cities requires not only good policy, practice, and engagement, but also architectural strategies that respond to how humans relate to each other and their surroundings. Convergence explores how designers can contribute to making urban housing better for everyone by addressing housing affordability, person-to-person interaction, and community engagement in increasingly-dense environments. Its primary objectives are: • Encouraging neighborliness by increasing chance encounters as well as reducing the sharp threshold between private and public space often found in apartment-style buildings. • Increasing the visibility of human activity to the street in a multi-floor, multi-family project. • Using new mass timber methods and modularity to improve initial building construction and cost while also incorporating sustainable practices to reduce resource use and operating cost. • Anticipating that modification and reconfiguration will be required in the future, and offering defined parameters to simplify that process. • Creating a variety of unit sizes while also offering future flexibility to respond to changing community needs. • Combining the familiar with the novel to connect the new community to its surroundings, bridge experiences, and manage change. / Master of Architecture / In the City of Alexandria, the Alexandria Re-Development and Housing Authority (ARHA) owns several affordable housing sites in desirable locations that it has been working to convert into more dense, mixed-income housing in partnership with private developers. While these projects have succeeded to some extent, housing in the City continues to become increasingly expensive, and wages for low-income and lower-middle class residents are not keeping pace with the increase in cost of living. This phenomenon is pushing many long-time and/or lower-wage residents to the suburbs and exurbs, limiting access to municipal resources and public transportation, and reducing quality of life. As a result, communities and families with long histories in the City are breaking apart and dispersing. Many advocates, policymakers, designers, and developers have turned to additional density as the most immediate response to these concerns. However, additional density isn’t enough; new buildings may house more people, but fail to address the other aspects of building thriving and diverse communities that connect people the way previous communities may have. Good housing and good communities need more than square footage, so it is time to look beyond conventional solutions. New approaches are needed to respond to how people are affected by changes to their living environments and communities, and create the kinds of positive outcomes that should be part of any new housing project. Therefore, if we want to design for living in cities, we have to have good policies, practices, and engagement, but we also need architectural strategies that respond to how humans relate to each other and their surroundings. Convergence explores how designers can contribute to making urban housing better for everyone by addressing housing affordability, person-to-person interaction, and community engagement in increasingly-dense environments. Its primary objectives are: • Encouraging neighborliness by increasing chance encounters as well as reducing the sharp threshold between private and public space often found in apartment-style buildings. • Increasing the visibility of human activity to the street in a multi-floor, multi-family project. • Using new mass timber methods and modularity to improve initial building construction and cost while also incorporating sustainable practices to reduce resource use and operating cost. • Anticipating that modification and reconfiguration will be required in the future, and offering defined parameters to simplify that process. • Creating a variety of unit sizes while also offering future flexibility to respond to changing community needs. • Combining the familiar with the novel to connect the new community to its surroundings, bridge experiences, and manage change.
87

A Future for Housing

Prentice, David Neil 30 June 2021 (has links)
This project seeks to propose an ideal model for housing in a future where it is no longer feasible at a lower density. It identifies several characteristics of good housing, primarily: individual response to site, desirability, and sustainability, then applies them in the design of an apartment building on a specific site. The project also touches on questions of what makes a living space desirable, namely the preservation of the tenant's individuality and the fostering of community, each of which is examined and applied through the architecture. The project stresses that individuality is supported through a tenant's choice of living space and, therefore, that buildings following this model should not be identical copies, but rather unique responses to their own sites following the guiding principles of this project. It addition, as a secondary objective, the project explores the intricacies of mass timber construction and building code. / Master of Architecture / As the population rises and it becomes clearer that we can no longer afford to gobble up land for low density housing, our idea of what housing should be must also grow. It's inescapable that the future of housing involves refocusing on medium density apartments so that we can house more people on less land, but making that happen would involve a paradigm shift in what we consider the ideal housing condition. Convincing people to stay in apartment buildings instead of moving into a single-family house requires buildings that respond to their individual site, provide desirable apartments, respect the environment, and preserve the sense of community that is often found in low density developments. This project seeks to propose a model for the future of housing.
88

"Fit Body" Sporting Centre / Sportovní centrum "Fit Body"

Janíček, Vít January 2014 (has links)
Master thesis processes documentation for the realization of the new building of the multi-functional sporting centre. Object is designed as the two storey building with the external thermal insulation system ETICS. Object is designed according to the appropriate legislation. Object fulfills demands for the low-energy standard. Building is without cellar with the flat warm roof. Load bearing constructions of the floor ceilings are made out of prestressed concrete panels SPIROL. Load bearing construction of the hall roof is made of the glulam timber beams and purlins with the bracing.
89

Análise numérica e experimental de vigas de madeira laminada colada em situação de incêndio / Numerical and experimental analysis of glued laminated timber in fire situation

Martins, Gisele Cristina Antunes 29 July 2016 (has links)
Elementos estruturais de Madeira Laminada Colada (MLC) têm sido muito utilizados na América do Norte e na Europa. Entretanto no Brasil há restrições quanto ao uso, principalmente, em razão da insegurança diante de potenciais riscos relacionados a incêndios. Este trabalho investigou o comportamento térmico e mecânico de elementos estruturais de MLC expostos à curva de incêndio-padrão ISO 834, preparados com duas espécies de madeira (Eucalyptus e Pinus) sem adição de tratamentos preservantes. Adicionalmente, elementos tratados com preservante ignífugo a base Borato de Cobre Cromatado (MOQ® OX 50CCBO) ou tratamento retardantes ao fogo (OSMOGUARD® FR100) também foram utilizados para analisar a influência na carbonização. O objetivo principal da pesquisa foi analisar a resistência ao fogo de elementos de MLC, avaliando a influência da espécie de madeira, a influência da densidade, bem como os efeitos dos tratamentos preservantes. O programa experimental foi realizado no forno horizontal a gás instalado no Departamento de Engenhara das Estruturas - EESC/USP, com dimensões internas de 3m x 4m x 1,5m, e as análises numéricas foram implementadas no pacote computacional ABAQUS. O modelo numérico, com vistas ao monitoramento a deflexão no meio do vão e a avaliação da distribuição da temperatura ao longo da profundidade dos elementos, foram desenvolvidos e os resultados obtidos foram comparados com os dados obtidos por meio das análises experimentais. Métodos de cálculo propostos por diferentes autores e regulamentações internacionais foram aplicados para verificação das propostas de dimensionamento em situação de incêndio. A comparação dos resultados mostrou que a utilização dos métodos de dimensionamento (simplificado ou avançado) representa risco à segurança contra incêndio caso utilize valores para a taxa de carbonização das espécies nacionais determinados a partir dos métodos de cálculo ou normas internacionais. / Structural elements of Glued Laminated Timber (glulam) have long been used in North America and Europe, but their use is still restricted in Brazil for safety reasons, especially related to potential risks in face of fire. The present work investigated the thermal and mechanical behavior of structural elements of glulam exposed to fire standard ISO 834. The glued laminated timber was produced from two wood species (Eucalyptus and Pinus) without any treatments. However, elements treated with wood treatments like Copper Chrome Boron (MOQ® OX 50 -CCB-O) or fire retardant treatment (OSMOGUARD® FR100) were also used to investigate their influence on charring. The main objective of this study was to assess the fire resistance of the glulam elements, evaluating the influence of wood species and, consequently, the influence of density, as well as the effects of preservative treatment. The experimental program was carried out in a gas oven, with internal dimensions of 3m x 4m x 1.5m, and the numerical analyses were performed by ABAQUS. The numerical analyses aimed to monitor the deflection in the middle of the span as well as the temperature distribution along the depth of the elements. The results obtained from both the experimental and numerical analyses were compared. Calculation methods proposed by different authors and international regulations have been applied for verification of the proposed design in fire. A comparison of the results show that the use of calculation methods (simplified and advanced) represents a risk to fire safety in case of using the values of char rate for Brazilian wood species determined from the calculation methods.
90

Desenvolvimento de um modelo estatístico para aplicação no estudo de fadiga em emendas dentadas de madeira / not available

Espinosa, Mariano Martinez 27 November 2001 (has links)
Madeira laminada colada (MLC) é um material de construção muito empregado em estruturas. Este produto é composto de lâminas classificadas de madeira, coladas horizontalmente, para formar peças estruturais de madeira grandes dimensões. A união das lâminas é realizada através de distintos tipos de emendas longitudinais, sendo as emendas dentadas as mais utilizadas. Considerando que os componentes estruturais de MLC, em geral, são solicitadas a carregamentos cíclicos, este trabalho tem por finalidade a proposta de um modelo estatístico para a determinação da vida à fadiga em menos dentadas de madeira. O trabalho foi realizado no Laboratório de Madeiras e de Estruturas de madeira (LaMEM), com o estudo teórico e experimental da fadiga em corpos-de-prova tracionados de ligações com emendas dentadas, baseado em um planejamento estatístico de experimentos e na NBR 7190/97. Os resultados contidos mostram que o modelo Polinomial Ortogonal Múltiplo da distribuição de Birnbaum-Saunders é de grande precisão e o mais adequado ao estudo da fadiga. O uso deste modelo pode ser de grande benefício, já que com ele se poderá estimar e caracterizar com maior confiabilidade e precisão a um menor custo a vida à fadiga em emendas dentadas de madeira, considerando as variáveis independentes de tensão e freqüência. / In the production of structural elements of Glued Laminated Timber (GLULAM), the horizontal union of lumbers are made with finger joints. Considering that the structural components of GLULAM need a great number of finger joints, and some of these structures are subject to cyclic loading, the objective of this work is to present a statistical model to estimate the fatigue life in lumber tension finger joints. The theoretical and experimental work was made in the Laboratory of Wood and Timber Structures (LaMEM), based on a statistical experiment design using tension tests and in agreement with the NBR 7190/97 code. The estimation procedure was based on the multiple orthogonal polynomial Birnbaum-Saunders model and the results show that the parameter estimates of the multiple orthogonal polynomial Birnbaum-Saunders model are obtained with at good accuracy and the most appropriate for the wood fatigue study. The use of the model can be of great benefit, since with it can be fit and characterize with greater reliability and precision at a smaller cost the fatigue life in finger joints of wood, considering the independent variables stress and frequency.

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