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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.
91

Passarela estaiada com tabuleiro de madeira laminada protendida em módulos curvos / Cable-stayed footbridge with stress laminated timber deck composed of curved modules

Pletz, Everaldo 25 February 2003 (has links)
É inegável a importância do desenvolvimento de tecnologias de uso racional da madeira e de solução de problemas de transportes em nossas cidades, principalmente por causa do processo crescente de urbanização do mundo. Existe também, a necessidade estética de se unir à alta tecnologia, o belo. As passarelas estaiadas com tabuleiro de madeira laminada protendida, em módulos curvos, atendem a todas estas exigências. A construção de um protótipo permitiu que a realização de ensaios estáticos e dinâmicos, cujos resultados evidenciaram a viabilidade técnica e econômica de passarelas estaiadas usando madeira de reflorestamento, de tabuleiros compostos apenas por placas de madeira laminada protendida e da construção de placas curvas de madeira laminada protendida. Também foi possível comprovar que as vibrações induzidas por pedestres são a condição mais crítica de projeto. A investigação da perda de curvatura do tabuleiro demonstrou o sucesso do projeto, embora mais estudos ao longo do tempo sejam necessários. Baseando-se nos resultados experimentais, realizou-se a calibração do modelo numérico, que permitiu realizar simulações para determinar quais variáveis definem a resposta da passarela construída. Sugestões de procedimentos de elaboração e construção de passarelas, assim como de criação de norma brasileira específica para pontes e passarelas de madeira, são apresentadas. / The ongoing, worldwide, large scale urbanization is stressing more and more the importance of developing new technologies concerned with the rational use of timber and with the solution of transportation problems in cities. There is also an aesthetical need of showing the melting of up-to-date high technology with beauty. The cable-stayed stress laminated timber footbridge, with curved modules meets all these needs. The buildings of a prototype, enable static and dynamic tests to be carried out. The experimental results revealed the technical and economical feasibility of the following items: a) cable stayed footbridges with timber from reforestation, b) decks only made of stress laminated timber, c) curved plates of stress laminated timber. It also revealed that the human induced vibrations leads to the most critical design condition. The loss of deck curvature study indicated the need of further research considering the time effect, to confirm the initial sucess achieved. Based on the results of these testings, the calibration of the numerical model was done. In order to investigate which variables are responsible for the footbridge response, several simulations were performed with the calibrated model. Guidelines for design and building of timber footbridges are presented. The creation of a brazilian code for timber bridges and footbridges is also suggested.
92

Classificação estrutural de peças de madeira de Pinus elliottii utilizando o módulo de elasticidade obtido pelo método de ondas longitudinais de tensão / Structural grading of Pinus elliottii timber using the modulus of elasticity obtained by longitudinal stress wave method

Andrade Junior, Jairo Ribas de 12 December 2016 (has links)
A classificação estrutural de peças de madeira possibilita melhor utilização do material, separando as peças de acordo com a sua resistência estimada. Nesse processo é feita a classificação visual, de grande importância no caso de madeiras do gênero pinus, e a classificação mecânica por meio de testes não destrutivos com objetivo de estimar o módulo de elasticidade. Com esse objetivo, além de ensaios de flexão estática, podem ser aplicados métodos dinâmicos baseados em medições das frequências naturais e densidade do material para a determinação do módulo de elasticidade da madeira. Nesse sentido o objetivo deste trabalho foi avaliar a eficiência do aparelho portátil Brookhuis Micro Timber Grader (MTG) na estimativa do módulo de elasticidade por meio de ensaios não-destrutivos de vibração longitudinal. Para tanto, foi utilizado um lote de peças estruturais de madeira da espécie Pinus elliottii classificado visualmente. Os resultados obtidos por esse aparelho foram comparados com os resultados de módulo de elasticidade obtidos em ensaio de flexão estática. Tendo em vista a sua praticidade, é recomendável a utilização deste método para a classificação estrutural de peças serradas de madeira. A classificação visual agregada a classificação mecânica são essenciais para a utilização do Pinus em vigas laminadas coladas, construções industrializadas de madeira e do sistema construtivo em woodframe. / The structural grading of wood allows better use of the material, sorting the specimen according to their estimated strength. In this process the visual grading is a fundamental matter in use of the structural Pinus elliottii and also the mechanical grading obtained by non-destructive methods in order to estimate the modulus of elasticity. For this purpose, in addition to the static bending tests, dynamic methods based on measurement of the natural frequencies and density of the material to determining the modulus of elasticity (MOE) of timber can be applied. The objective of this study was to evaluate the efficiency of portable device Brookhuis Micro Timber Grader (MTG) in estimating the modulus of elasticity by non-destructive testing of longitudinal vibration. It was used structural pieces of wood species Pinus elliottii rated visually. The results obtained by this device was compared with the modulus of elasticity results obtained in static bending tests. Given its convenience and low cost, it is recommended to use this method for structural grading of timber sawn pieces. The visual and stress grading are essencial for the use of Pines in glued laminated timber, industrilization timber constructions and woodframe constructions.
93

Strength and Stability of Cross-Laminated-Timber Walls at Short and Long Term / Résistance et stabilité des murs en bois lamellé-croisé à court et à long terme

Perret, Olivier 04 December 2017 (has links)
Ce mémoire de thèse aborde le problème du flambement de murs en bois lamellé-croisé. Ces panneaux de bois, constitués de planches collées perpendiculairement, sont de plus en plus utilisés dans la construction. La tendance actuelle du marché est de concevoir des immeubles de grande hauteur, ce qui soulève la question de la résistance en compression de ces murs. Il s'avère que le bois est fortement anisotrope. En particulier, la raideur et la résistance en cisaillement perpendiculaire aux fibres, également appelé cisaillement roulant, sont beaucoup plus faibles que dans la direction parallèle aux fibres. Ce fort contraste nécessite un critère de conception plus élaboré que les outils classiques utilisés dans l'ingénierie du bois. Ce travail est organisé en deux parties. Dans la première partie, la raideur équivalente de cisaillement transverse d'un panneau de bois lamellé-croisé est étudiée. Des bornes sont établies par une approche théorique. Ces bornes sont validées par un nouveau dispositif expérimental qui permet la mesure de la raideur en cisaillement roulant avec une variabilité plus faible que le test textit{single-lap} classiquement utilisé. Dans la deuxième partie, ces données sont utilisées dans l'analyse du flambement de panneaux en bois lamellé-croisé en raffinant progressivement le problème. Dans un premier temps, la charge critique de flambement linéaire d'une plaque épaisse sans imperfections est établie. Cette charge critique est basée sur une nouvelle théorie de plaque d'ordre supérieur et montre que la charge critique de flambement basée sur une théorie de plaque mince (Kirchhoff-Love) ne peut pas estimer correctement la résistance de murs en bois lamellé-croisé. Dans un second temps, l'influence des imperfections est étudiée en adaptant l'approche classique de Ayrton et Perry à une poutre de Timoshenko. Cette extension a révélé qu'un nouveau critère de résistance doit être satisfait lors du flambement qui est spécifique aux murs en bois lamellé-croisé. Dans un dernier temps, cette analyse est étendue aux charges permanentes en supposant une loi de fluage simple qui conduit à un nouveau critère de conception simple qui pourrait facilement être adopté dans les codes de conception actuels / This PhD thesis addresses the issue of CLT wall buckling. These wooden panels, made of boards which are glued cross-wise, are more and more used in construction. The current trend of the market is to design high-rise buildings which raises the issue of the compressive strength of such walls. It turns out that wood is a highly anisotropic material. Especially, the shear stiffness and strength perpendicular to the grain (rolling shear) are much weaker than in the direction parallel to the grain. This high contrast requires more elaborate design criteria than classical tools used in timber engineering. This work is organized in two main parts. First, the equivalent rolling-shear behavior of a CLT layer is investigated. Bounds are established for the stiffness of an equivalent layer using a theoretical approach. These bounds are validated by means of a new experimental set-up which allows the measurement of the rolling shear stiffness with less variability than the classical single lap shear test. In the second part, this data is used in the buckling analysis of CLT walls with increasing refinements. First, the linear buckling load of a thick plate without imperfection is established. This load is based on a new higher-order plate theory and reveals that the critical load based on a thin plate theory (Kirchhoff-Love) cannot predict correctly the strength of CLT walls. Then, the influence of imperfections is introduced adapting the classical approach from Ayrton and Perry to the case of a Timoshenko beam. This extension reveals that a new design criterion has to be satisfied under buckling which is specific to CLT. Finally, this analysis is extended to long term loads assuming a simple creep law and leading to a new simple design criterion which may be easily introduced in current design codes
94

Äventyrstorn : En undersökning av konstruktionslösningar och material

Frisk Carlman, Joel January 2018 (has links)
Deep Wild är ett företag som bland annat   specialiserar sig på produktutveckling och byggande av äventyrsanläggningar.   Kunder till företaget har efterfrågat ett typ av äventyrstorn som det är   möjligt att åka zipline från samt utföra andra aktiviteter såsom klättring   på. Då Deep Wild inte har egen kompetens gällande dimensionering och   projektering av denna typ av torn har en förfrågan skickats ut till studenter   för att se om det fanns intresse att ta fram en lösning på utförandet. Syftet   med arbetet är att undersöka hur ett äventyrstorn som detta kan konstrueras   och ta fram en lösning på utförandet. Tornet dimensioneras enligt gällande   Eurokoder. De laster som genereras av specialutrustningen tornet förses med   finns i Svensk Standard. Två lösningar på möjliga utföranden tas fram, ett   med alla bärande delar i stål och ett med lämpliga bärande delar i trä. Dessa   jämförs sedan med hänsyn till lämplighet. Det visar sig att det finns många   fördelar med att bygga tornet med enbart stålprofiler. Med stål som material kan   alla bärande delar köpas ur det lagerförda sortiment som erbjuds på   marknaden. Med trä finns inga lagerförda dimensioner att tillgå för de laster   som uppstår. Vid de knutpunkter som dimensionerats visar det sig att de   utförda i stål enkelt kan utföras så att de har mycket god säkerhetsmarginal.   Knutpunkterna i träkonstruktionen klarar de dimensionerande lasterna endast   med små marginaler. Genom att mer specialanpassa utseendet hos konstruktionen   och dess verkningssätt så kan möjligtvis utförandet i trä gynnas. En   prisjämförelse mellan de två materialen visar att skillnaden i materialpris   är försumbar i sammanhanget. Två alternativa stabiliseringssystem undersöks   för tornet. Det ena är att staga med en fackverkskonstruktion som använder   sig av dragna stålstänger och tryckta strävor av respektive   utförandematerial. Det andra är att staga tornet genom skivverkan i   klätterväggen som uppförs på tornets ena sida. Skivverkan har sina fördelar   då det möjliggör tryckta strävor på olika höjd i tornet. Fackverkskonstruktionen   är dock att rekommendera då denna kan dimensioneras att ta avsevärt högre   laster. Det naturliga nästa steget i arbetet ligger i att ta fram ett   förfrågningsunderlag tillräckligt komplett för att kalkyleras. / Deep Wild is an   adventure company which specializes in product development among other   things. Customers of the company have been asking for a tower from which it’s   possible to exercise different kinds of adventure activities, such as   ziplining and climbing. Deep Wild doesn’t have in house experience from   constructing supporting structures that are not directly related to the   special equipment used to exercise these activities. Therefore students have   been asked to find a solution on how to construct a tower like this. The   purpose of this study is to investigate how an adventure tower can be   constructed. The tower is structurally designed using Eurocodes and the loads   generated from the activities exercised appear in European Standard. Two   possible solutions for the construction is developed, one with all supporting   parts in steel and one with selected supporting parts in wood. These are then   compared to each other with regard to their performance. The results show   that there are many advantages using only steel profiles. All steel profiles   required for the construction can be bought out of existing stock from   producers. To use wooden profiles it is required to place orders on standard   dimensions that are not part of the producers existing stock. The joints designed   shows that using steel profiles these can easily be designed to provide a   high safety margin. The joints designed using steel connectors to wooden   profiles provides enough support only with small safety margins. By adjusting   the design of the towers supporting system the use of wooden profiles could   possibly be benefitted. A price comparison based on the price of material   shows that the difference between laminated timber and steel in this   construction is negligible. Two alternative ways of stabilizing the tower   have been investigated. One with tensioned steel bracing and compressed   bracing using the different construction materials. The other one using wall   diaphragms on the side of the tower clad with climbing wall. The wall   diaphragms method has its advantages because it makes it possible to place   compressed bracings on different heights in the tower. The system with   tensioned bracings can take higher loads and provide better safety margins   and is therefore the recommended way of stabilizing this tower. The next step   of this project is to provide complete enough material to calculate the cost   of constructing. / <p>Betyg 2018-06-05</p>
95

Analysis of shear wallsfor multi-storey timber buildings

Vessby, Johan January 2011 (has links)
This doctoral thesis addresses questions of how wind loads acting on multistoreytimber buildings can be dealt with by structural design of such buildings.The conventional use of sheathing either nailed or screwed to a timberframework is considered, together with other stabilizing structures such ascross-laminated timber panels.The finite element method was employed in simulating the structuralbehaviour of stabilizing wall units. A series of studies was carried out of walls inwhich the sheathing was nailed to a timber frame. Different structural levelswere studied starting with modelling the performance of single sheathing-toframingconnections, to the use of models for studying the overall structuralbehaviour of walls. The results of calculations using models for simulation ofwalls subjected to different loading agree reasonably well with experimentalresults. The structural properties of the connections between the sheathing andthe frame, as well as of the connections between the members of the frame,were shown to have a substantial effect on the simulated behaviour of shearwall units. Both these types of connections were studied and described inappended papers.Regarding cross-laminated timber wall panels, it was concluded that walls witha high level of both stiffness and strength can be produced by the use of suchpanels, and also that the connections between the solid wall panels can bedesigned in such a way that the shear forces involved are transmitted from onepanel to the next in an efficient manner.Other topics in the thesis include the properties of connections between shearwalls and the rest of the building. Typically high tension forces occur at specificpoints in a timber structure. These forces need to be transmitted downwards inthe structure, ultimately connecting them to the substrate. A lap-joint that maybe used for this purpose has been studied using generalized Volkersen theory.Finally the maximum capacity of a conventional rail to substrate connection hasbeen examined using linear and nonlinear fracture mechanics.
96

Avaliação tecnológica de emendas por entalhes múltiplos reforçadas com fibras para madeira laminada colada / Technological evaluation of finger joints reinforced with fibers for glued laminated timber

Bourscheid, Cleide Beatriz 28 April 2017 (has links)
Submitted by Claudia Rocha (claudia.rocha@udesc.br) on 2017-12-15T11:25:42Z No. of bitstreams: 1 PGEF17MA082.pdf: 2704849 bytes, checksum: 402c8ed2d802138ba830b989401226b5 (MD5) / Made available in DSpace on 2017-12-15T11:25:42Z (GMT). No. of bitstreams: 1 PGEF17MA082.pdf: 2704849 bytes, checksum: 402c8ed2d802138ba830b989401226b5 (MD5) Previous issue date: 2017-04-28 / FAPESC / The use of the fiber reinforcement in structural elements of Glued Laminated Timber (Glulam) is advantageous because of increase its strength and stiffness. However, few studies have evaluated the performance of reinforcement on finger joints, which, even under excellent manufacturing conditions, shows less strength than solid wood, making this kind of joint one of the main weaknesses of Glulam. In this context, the present dissertation aims to evaluate the performance of reinforcement with fibers in finger-joints for use in Glulam. The performance analysis was developed under two aspects: (i) the tensile strength parallel to grain performance in two geometries, "A" and "B", on joints, with three reinforcement compositions, "Glass", "Glass2" and "Carbon", in two species of wood, Pinus taeda and Eucalyptus spp. and (ii) the performance of Glulam beams of Eucalyptus spp. with three reinforcement compositions, "Glass", "Glass2" and "Carbon", in tensile strength parallel to grain, normal tensile, strength to shear and three points bending test. All tests were performed according to the guidelines of NBR 7190/1997, using the Scott-Knott and Tukey tests for statistical analysis with 95% of confidence interval. The results show that the finger-joints, even within normative requirements, significantly reduces (up to 43%) the tensile strength parallel to grain, regardless of geometry or species. For the samples of Eucalyptus spp., the treatments "B-Glass2", "B-Carbon" and "A-Glass2" presented average strength equivalent to solid wood. For specimens of P. taeda, the treatments with the same performance as solid wood were "A-Glass2", "A-Carbon", "B-Glass2", "B-Carbon" and "B-Glass". It can be concluded that the application of two layers of reinforcement of glass fibers or one layer of carbon, concentrated in the region of the finger-joints with the geometry B, increases significantly (in up to 71% for P. taeda and 25% for Eucalyptus spp. in the treatments with better performance) the tensile strength parallel to grain in both species evaluated. It was also concluded that the apparent densities (Pinus taeda ρap,m= 0.49 and Eucalyptus spp. ρap,m= 0.60) show poor correlation with the tensile strength parallel to the fibers. The performance of the glulam beams of Eucalyptus spp. did not present significant differences for the evaluation of the bonding lines. However, in the flexural strength, the treatments "Glass 2" and "Carbon" were significantly superior to the glulam beams without reinforcement, reaching at increments of 37.8% and 40.5%, respectively, in the bending strength. The modulus of elasticity did not differ significantly among. It was observed that the mode of rupture was by tensile in the finger-joints region in all the beams evaluated in bending test, however, the bending strengths were higher than tensile strengths parallel to grain, indicating influence of the thickness of the blades and thickness of the reinforcements in the performance of the reinforced finger-joints. In this way, it is possible to conclude that the application of concentrated reinforcement in finger-joints significantly improves the performance of glulam beams of Eucalyptus spp. to bending, as well as the tensile strength parallel to grain for P. taeda / A aplicação de reforço com fibras em elementos estruturais de Madeira Laminada Colada (MLC), na linha de colagem de maior esforço, se apresenta de maneira vantajosa por aumentar sua resistência mecânica e sua rigidez. Todavia, poucos estudos avaliam o desempenho do reforço sobre as emendas longitudinais, que, mesmo em condições excelentes de manufatura, têm resistência menor que a da madeira maciça, tornando as emendas um dos principais pontos de fragilidade da MLC. Nesse contexto, a presente dissertação tem por objetivo avaliar o desempenho do reforço com fibras em emendas por entalhes múltiplos (finger-joints) para utilização em MLC. A análise de desempenho foi desenvolvida sob dois aspectos: (i) desempenho à tração paralela às fibras de duas geometrias, “A” e “B”, para emendas, com três composições de reforço, “Vidro”, “Vidro2” e “Carbono”, em duas espécies de madeira, o Pinus taeda e o Eucalyptus spp. e (ii) o desempenho de vigas em MLC de Eucalyptus spp.com três composições de reforço, “Vidro”, “Vidro2” e “Carbono” quanto à resistência à tração paralela às fibras, tração perpendicular às fibras, cisalhamento e flexão estática. Todos os ensaios foram executados de acordo com as diretrizes da NBR 7190/1997, sendo empregados os testes de Scott-Knott e Tukey para as análises estatísticas com 95% de confiabilidade. Os resultados mostram que as emendas por entalhes múltiplos, mesmo dentro dos referenciais normativos, diminuem significativamente (em até 43%) a resistência à tração paralela às fibras, independentemente da geometria ou da espécie utilizada. Para as amostras de Eucalyptus spp., os tratamentos “B-Vidro2”, “B-Carbono” e “A-Vidro2” apresentaram resistência mecânica média equivalente à madeira maciça. Para as amostras de P. taeda, os tratamentos com desempenho mecânico similar à madeira maciça foram “A-Vidro2”, “A-Carbono”, “B-Vidro2”, “B-Carbono” e “B-Vidro”. Pode-se concluir que a aplicação em duas camadas de reforço de fibras de vidro ou uma camada de carbono, ambos concentrados na região das emendas por entalhes múltiplos com a geometria B, aumenta significativamente (em até 71% para o P. taeda e 25% para o Eucalyptus spp. nos tratamentos com melhor desempenho) a resistência à tração paralela às fibras em ambas espécies avaliadas. Conclui-se ainda que a densidade aparente (P. taeda ρap,m= 0,49 e Eucalyptus spp. ρap,m =0,60 ) apresenta fraca correlação com a resistência à tração paralela às fibras. O desempenho mecânico das vigas MLC de Eucalyptus spp. não apresentou diferenças significativas para a avaliação das linhas de colagem. Entretanto, na resistência à flexão estática, os tratamentos “Vidro 2” e “Carbono” foram significativamente superiores às vigas MLC sem reforço, chegando a incrementos de 37,8% e 40,5%, respectivamente, à flexão estática. Os módulos de elasticidade não diferiram significativamente entre si. Foi constatada ruptura por tração na região das emendas em todas as vigas avaliadas à flexão estática, entretanto as resistências à flexão foram superiores às resistências à tração paralela às fibras, indicando influência da espessura das lâminas e da espessura dos reforços no desempenho mecânico das emendas reforçadas. Desta forma, é possível concluir que a aplicação de reforço concentrado na região das emendas por entalhes múltiplos melhora, significativamente, o desempenho de vigas MLC de Eucalyptus spp. à flexão, bem como a resistência à tração paralela às fibras para o P. taeda
97

The Effect of Steel Strapping Tensioning Technique and Fibre-Reinforced Polymer on the Performance of Cross-Laminated Timber Slabs Subjected to Blast Loads

Lopez-Molina, America Maria 09 October 2018 (has links)
Engineered wood products (EWP) are becoming extremely popular and a viable material option for the construction of residential, commercial, and hybrid buildings. Cross-laminated timber (CLT) is among one of the many EWP available in North America, which can be utilized for many different applications such as: walls, floors, and roofs. Despite the available requirements in the Canadian blast design standard (CSA, 2012) with regard to the design of wood structures, there are currently no provisions on how to retrofit timber structures to improve their performance when subjected to blast loads. The current study is aimed at investigating the effect of different retrofitting alternatives in order to improve the overall behaviour of CLT when exposed to out-of-plane bending. The experimental program examined the behaviour of seventeen reinforced CLT slabs. Testing was conducted at the University of Ottawa by means of a shock tube capable of simulating high strain rates similar to those experienced during a blast event. The current study was divided into two phases. The first consisted of CLT slabs retrofitted with steel straps where strap spacing, location, and order of installation was investigated. The second phase focused on the development of dynamic properties of CLT panels when reinforced with GFRP. Lay-up configuration and fabric orientation were among the parameters explored. The results from the experimental program show that reinforcing the panels with steel straps had minimal effect on the ultimate strength, but significant levels of post peak resistance and ductility was achieved. The horizontal straps were able to restrict the failure to small regions and to promote flexural failure by preventing rolling shear failure. It also eliminated flying debris and enhanced the ultimate strength, stiffness as well as ductility. Applying GFRP layers enhanced the overall behaviour of the slab resulting in a significant increase in peak resistance, ductility, and stiffness when compared to the dynamic results of an unretrofitted panel. The post peak resistance was also greatly improved. In particular, applying stacked quadraxial lay-up configuration significantly improved the ductility and resulted in the greatest post peak resistance. The effect of steel straps on damaged and retrofitted was relatively minimal, and only partial recovery of the resistance and the stiffness was achieved. GFRP with full confinement yielded better performance compared to the unretrofitted and undamaged counterpart. More work is needed to quantify the benefits of using GFRP in these applications.
98

Jämförelsestudier mellan olika typer av korslimmat träbjälklag: : Undersökning av konsekvenser vid ändring från betong- till korslimmat trä- bjälklag i ett flervåningshus

Al-Mulla, Tiba January 2018 (has links)
Timber is one of the most common materials that had been use for a long time. The need for new buildings will affect the climate negatively, that is why it’s necessarily to find new ways to build quickly and sustainably. Cross-laminated timber (CLT) product came in the 1990- century. The material was developed to be used in high residential wood constructions buildings. The material considered to have good properties compared with other types of wood material, some of the studies showed the possibilities of building high residential with the CLT material. Such high rises buildings work best when CLT wood constructions combined with other materials, which called, Composite constructions. Case study preformed theoretically in Fullriggaren building in Alderholmen in Gävle city, the building have 14 floors and about 40 m high. With the purpose of trying to investigate the consequences that occur when the concrete floor slabs were replaces  with CLT wood floor slabs, taking into account the rules and standards for fire safety, acoustics, oscillations and vibrations. In order to achieve this and to determine the most suitable alternatives, the different types of CLT-wood floor slabs was compared. The building studied in its design and execution, and a simpler model created in Revit 2018. The challenge was that the building has a long span of maximum 10 m. The different types of CLT floor slabs which compared in the study was, CLT timber joist slaps, flat floor slab and CLT wood floor slabs in combination with steel hat beams and other beam steel types. Each type of floor slabs had its advantages and disadvantages, but the results and studies showed that timber and concrete composite floor slab combined with steel hat beams are the best possible options for the construction in Fullriggaren building, where the floor slab height is the shortest compared to other CLT wood floor types. With the chosen floor slab, the problem of vibration and oscillations will minimize. When using such a floor slab, the building height will increase, which means in this case, removing an entire floor from the building. / Trä är ett av de vanligaste material som har används sedan länge i byggkonstruktioner. Behovet av nya byggnader kommer att påverka klimatet på ett negativ sätt, därför är det bra att bygga snabbt och hållbart. Korslimmat trä (KL-trä) är en produkt som kom under 1990-talet. Trämaterialet utvecklades där den kan användas i träkonstruktioner i flervåningshus.Materialet anses ha goda egenskaper jämfört med andra typer av trämaterialen, litteraturstudier visade på möjligheten att bygga högt med KL-trämaterialet. Liknande höghus fungerar bäst när KL-träkonstruktioner kombineras med andra material s.k. Hybrida konstruktioner. Fallstudien utfördes teoretisk i  Fullriggarenbyggnaden i Alderholmen i Gävle, som består av 14 våningar och är ca  40 m högt. Syftet var att undersöka konsekvenserna som uppstår när betongbjälklaget ersätts med KL-träbjälklag, hänsyn tas till regler och normer när det gäller brandsäkerhet, akustik, svängningar och vibrationer. För att uppnå detta och kunna bestämma lämpligaste alternativ, jämfördes olika typer av KL-träbjälklag. Byggnaden undersöktes beträffande konstruktion och utförande, och en enklare modell skapades i Revit 2018. Utmaningen var att byggnaden har långa spännvidder med max 10 m. Olika typer av KL-bjälklag jämfördes som kassettbjälklag, samverkanbjälklag, plattbjälklag och KL-trä bjälklag i kombination med stålhattbalkar och andra ståltyper. Varje typ av bjälklag har sina fördelar och nackdelar, men resultatet och studierna visade att samverkabjälklag kombinerad  med stålhattbalkar är den bästa lösningen för konstruktionen i Fullriggaren, då dess tvärsnitthöjd är den minsta jämfört med andra KL-träbjälklagtyper. Med det valde  bjälklaget minskas även problemet med vibrationer och svängningar. Vid användning av detta bjälklag kommer byggnadshöjden att ökas, vilket leder till att  en våning måste väljas bort.
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Mätning av fuktkvot i sammansatta KL-träelement / Moisture content measurements in assembled CLT-elements

Andersson, Josefine, Svensson, Simon January 2018 (has links)
Fuktskador är ett problem som kan uppstå vid byggnation i trä om konstruktionen exponeras för nederbörd under byggtiden. Mätning av fuktkvoter i trä kan utföras med flera olika instrument och metoder. Syftet med arbetet är att studera fuktkvotsförändringar i korslimmade träelement som utsätts för långvarig nederbörd i laborationsmiljö. För att utveckla detta område har Linnéuniversitetet tillsammans med Saab utvecklat ett eget mätinstrument. Instrumentet mäter resistans i trä som jämförs med mätvärden från ett annat instrument vid namn Gigamodule. Det egenutvecklade sensorkortet är fortfarande under utveckling. Förutom i arbetets försöksuppställning testas instrumentet även i en byggnad i Växjö. För kontroll av mätresultat har fler metoder och instrument använts. Två modeller har använts som representerar detalj vid anslutning av väggelement-och mellanbjälklag. Båda modellerna har under lika lång tid varit nedsänkta i vattenbad. Försöksuppställningen har utförts mellan 19:e april och 18:e maj 2018. Mätningar och beräkningar har resulterat i jämförbara resultat. Skillnader i resultat utifrån träets fiberriktning har visats från flera instrument. KL-träelementen har uppvisat en god förmåga att trots höga fuktkvotsvärden torka ut och återgå mot normala värden under mätperioden. / Moisture related damage is an occurring problem in wood-based buildings if the material is exposed to rainfall during construction. Measurement of moisture content can be done with various instruments and methods. The purpose of the thesis is to study change in moisture content in cross-laminated-timber, with prolonged exposure to water in laboratory environment. To advance the field, the Linnaeus University has been developing a measurement instrument of their own in collaboration with the company Saab. The instrument measures electrical resistance in wood where the obtained values will be compared to similar measurements from a product named Gigamodule. The self-developed sensor card is still a product under development. In addition to the lab setting measurements the instrument was also installed in a local building in Växjö. To verify the result from the previously mentioned resistance measurers additional instruments and methods have been utilized. Two separate models have been used to represent the detail of the connection between the wall element and the joist. Both models have been submerged under water for an equal amount of time. The experimental setting took place between the 19th of April to the 18th of May 2018. The measurements and calculations have been resulting in values that can be the subject of internal evaluation. Difference in result based on the direction of the grain have been observed in several measurement methods. The CLT-elements demonstrated good drying properties despite periodically high moisture content and the wood indicate a return towards initial levels of moisture.
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Análise de elementos estruturais de MLC na flexão com base na versão de revisão da norma ABNT NBR 7190:2013. / Analysis of glulam elements in bending based on the revision version of ABNT NBR 7190: 2013 Standard.

Gomes, Nádia Barros 20 February 2018 (has links)
Submitted by Nádia Barros Gomes (nadiabarrosg@gmail.com) on 2018-04-11T16:08:14Z No. of bitstreams: 1 DISSERTAÇÃO FINAL.pdf: 6090303 bytes, checksum: ce2f253c72b32bcfc50f67b58a252528 (MD5) / Approved for entry into archive by Pamella Benevides Gonçalves null (pamella@feg.unesp.br) on 2018-04-12T12:36:26Z (GMT) No. of bitstreams: 1 gomes_nb_me_guara.pdf: 6090303 bytes, checksum: ce2f253c72b32bcfc50f67b58a252528 (MD5) / Made available in DSpace on 2018-04-12T12:36:26Z (GMT). No. of bitstreams: 1 gomes_nb_me_guara.pdf: 6090303 bytes, checksum: ce2f253c72b32bcfc50f67b58a252528 (MD5) Previous issue date: 2018-02-20 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O objetivo desta pesquisa consistiu na avaliação do modelo de cálculo proposto pela versão de revisão da Norma Brasileira de Estruturas de Madeira ABNT NBR 7190:2013 para avaliação do comportamento de elementos de MLC na flexão. Foram considerados elementos de MLC com dimensões padronizadas de 5 x 5 x 115 cm para realização dos ensaios experimentais de flexão, tendo-se em vista a da rigidez (EI) para posterior comparação com os resultados numéricos e teóricos. Foram avaliados, também neste caso, os modos de ruptura apresentados nos ensaios experimentais por cada sistema. Na confecção dos elementos de MLC foram utilizadas madeiras de reflorestamento de pinus e eucalipto da região de Itapeva – SP coladas com resina resorcinol formaldeído. Todas as lâminas de madeira passaram por processo de classificação mecânica e visual. As simulações numéricas foram realizadas no software ANSYS, que tem como base o método dos elementos finitos e estas serviram para a avaliação das distribuições das tensões nas regiões de interesse dos elementos de MLC. Os ensaios experimentais de flexão e de caracterização dos materiais foram no Laboratório de Propriedades dos Materiais da UNESP/Itapeva a partir da utilização da Máquina Universal de Ensaios EMIC com capacidade de 300 KN. Como resultado, observou-se que o modelo teórico proposto pela ABNT NBR 7190:2013 mostrou, para este trabalho, maior aproximação com os resultados experimentais e numéricos para as madeiras de pinus. Além disso, os modos de ruptura obtidos teoricamente foram verificados para as análises experimental e numérica realizadas. / The aim of this work was to evaluate the calculation model proposed by the revision version of the ABNT NBR 7190: 2013 Wood Structures Brazilian Standard to evaluate the behavior of Glued Laminated Timber in bending. Glulam elements with standard dimensions of 5 x 5 x 115 cm were considered to perform the experimental bending tests considering the stiffness (EI) for later comparison with numerical and theoretical results of EI. The failure modes presented in the experimental tests by each system were also evaluated. In the preparation of the glulam elements, pine and eucalyptus reforestation woods from the Itapeva - SP region were glued with resorcinol formaldehyde resin. All the wood layers were classified by mechanical and visual process. The numerical simulations were performed in the ANSYS software, which is based on the finite element method and these were used to evaluate the stress distributions in the areas of interest of the glulam elements. Experimental bending tests and material characterization tests were performed at the Materials Properties Laboratory of UNESP / Itapeva using the Universal Testing Machine - EMIC with a capacity of 300 KN. As a result, it was observed that the theoretical model proposed by ABNT NBR 7190: 2013 standard showed, for this work, greater approximation with the experimental and numerical results for pine woods. In addition, the failure modes obtained theoretically were verified for the experimental and numerical analyzes performed.

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