Joints are critical parts of timber structures, transmitting static and dynamic forces between structural members. The ultimate behavior of e.g. a building depends strongly on the structural configuration and the capacity of its joints. The complete collapse of a building or other less extensive accidents that may occur usually start as a local failure inside or in the vicinity of a joint. Such serious failures have recently occurred in the Nordic countries. Especially the collapses of two large glued-laminated timber (glulam) structures clearly indicate the need of an improved joint design. The trend toward larger and more complex structures even further increases the importance of a safer design of the joints. One aim of this partly experimentally and partly numerically based work has been to investigate if the short term capacity of steel-timber dowel joints loaded parallel to the grain is affected by an initial drying exposure. The experimental results showed that the load-bearing capacity of the joints is indeed reduced by such moisture changes. Moisture induced stresses was mentioned to be the explanation. The key point is that the climates chosen in the present work (20°C / 65% RH and 20°C / 20% RH) are equivalent to service class 1 according to EC5 (Eurocode 5 2004). Thus, EC5 predicts no decrease in load-bearing capacity, in relation to the standard climate used during testing. A decrease in load-bearing capacity in the range of 5-20%, which was found in the present work, is of course not negligible and, therefore, there could be a need to introduce the effect of drying in design codes. Because similar results were also observed for a double-tapered glulam beam, further work should consider timber structures in general. Two numerical methods in order to predict the capacity of multiple steel-timber dowel joints loaded parallel to the grain were tested in the thesis. For the first method, where fracture mechanics (LEFM) concepts were implemented, a good correlation with the experimental results was seen. Also for the second method, where the capacity for a single dowel-type joint as given in EC5 was used as a failure criterion, a good correlation to traditional EC5 calculations of multiple dowel-type joints was seen. One advantage of using numerical methods in design is that the capacity of the joint can be calculated also for cases when the dowels are placed in more complex patterns. From both a structural and an architectural point of view this can be very important. In addition, such numerical methods are effective tools for the structural engineer when considering complicated loading situations in joints, i.e. eccentric loading giving moments in the joint.

Samhället efterfrågar idag i allt högre grad miljövänlig och hållbar byggnation. Ett sätt möta dessa nya krav på miljövänlig byggnation är att använda mer trä då detta minskar koldioxidutsläpp genom substitutionseffekten. Syftet att undersöka huruvida traditionella fogningstekniker som helt utförs i trä kan ersätta samtida fogar i framtida byggnation. Målet är att visa att detta är möjligt ur hållfasthetssynpunkt. Undersökningen kommer att begränsas till att undersöka en pelar-balk-anslutning där den traditionella fogen representeras av tre olika varianter tapp i tapphålsfog och den samtida av balksko. Fogarna undersöks beräkningsmässigt samt genom försök där belastningsfallet ämnar ge en hög tvärkraft. Resultaten pekar på att det är möjligt att introducera den undersökta traditionella träfogningstekniken vid samtida byggnation. / Societies demand for environmentally friendly and sustainable construction is ever increasing. One way to meet these new demands on environmentally friendly construction is to use more wood which decreases carbon emissions through the substitution effect. This report aims to research whether traditional joinery techniques entirely executed in wood can replace contemporary joinery techniques in future construction. The goal is to show whether this is possible from a strength standpoint. The research will be limited in that it will strictly seek to study a pillar-beamconnection where the traditional joint researched will be three varying mortise and tenon joints and the contemporary joint is a joist hanger. The joints will be analyzed with calculation and experimentation where the load case aims to produce mainly shear in the joint. The results point towards it being possible to introduce this traditional joint in contemporary construction.

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.

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.

In recent years, industrialised house building has gained shares on the Swedish house building market. The market demands for industrialised house building are exceeding the available supply of housing and experiencing a substantial increase in the housing production costs. For industrialised house building, the design has been identified as a critical phase with the systematization of the design a necessary part of industrialisation. Therefore, companies strive towards the inclusion of standardization and controlled processes in the design phase. Product platforms have proved to be related to the standardization of processes and products. Introducing a product platform approach in the design phase of house building could be a way to improve the design and ensure value creation in entire processes. Thus, the aim of this research is to outline means to support and improve the design phase of industrialised house building by using a product platform approach. A Swedish multi-storey house building company that uses glulam post and beam building system with a focus on platform development was used as the single case study in this research. The company intends to achieve increased efficiency by moving towards industrialized approaches. Empirical data were mainly gathered from interviews, observations, workshops, and document analysis. The findings present the existing challenges in the housing building industry and outlines twenty critical success factors that need to be considered in the design phase. Also, the result outlines support methods and tools that can be used for the improvement of the design phase when applying a product platform approach. Moreover, a flexible product platform can be developed with the support of parametric modelling and used to design building components having an engineer-to-order characteristic. Finally, the results show that a building system can be considered as part of a product platform in light of the necessity of an adequate support in the design process to maintain a sustainable platform. Thus, the contribution includes the addition of knowledge to platform theory in general and its application on the design phase of industrialised house building. / Under de senaste åren har det industriella husbyggandet tagit andelar på den svenska husbyggnadsmarknaden. Behovet av bostäder på marknaden överstiger tillgången och med ökning av bostadsproduktionskostnaderna som konsekvens. För det industriella husbyggandet har projekteringen identifierats som en avgörande fas och dess systematisering är en nödvändig för industrialiseringen. Som en följd strävar företag i segmentet efter att inkludera standardisering och kontrollerade processer i projekteringen. Produktplattformar har kunnat kopplas till standardisering av processer och produkter. Införandet av produktplattformar i projekteringen kan vara ett sätt att förbättra designen och säkra värdeskapandet igenom hela processen. Således är syftet i denna avhandling att ta fram medel för att stödja och förbättra projekteringen för industriellt husbyggande genom att tillämpa en ansats med produktplattformar. Ett svenskt byggnadsföretag med flera våningar som använder limträ- och balksystem med fokus på plattformsutveckling användes som en enda fallstudie i denna forskning. En fallstudie har genomförts på ett företag som bygger flervåningshus med ett pelar-balksystem i limträ med fokus på plattformsutveckling. Företaget har ambitionen att nå högre effektivitet genom att röra sig mot ett mer industriellt tillvägagångssätt. Data samlades in från intervjuer, observationer, workshops och dokumentanalyser. Resultaten visar vilka de befintliga utmaningarna är för husbyggandet och presenterar tjugo kritiska framgångsfaktorer som ska beaktas i projekteringen. Studien har även tagit fram supportmetoder och verktyg som kan användas för att förbättra projekteringen vid tillämpning av produktplattformar. Vidare, en flexibel produktplattform kan utvecklas med stöd av parametrisk modellering och användas för att projektera byggnads-komponenter med engineer-to-orderegenskaper. Slutligen, resultaten pekar mot att ett byggsystem kan betraktas som en del av en produktplattform ur perspektivet att tillräckligt med stöd i projekteringen krävs för att underhålla en hållbar plattform. Således, arbetet har bidragit med kunskap till teori om plattformar i allmänhet och dess tillämpning på projekteringen för industriellt husbyggande.

This thesis aims to develop knowledge of non-metallic connections in order to develop and change the Swedish wood architecture as well as wood structures. The main question being "Are metal-free connections suitable for contemporary timber buildings?". In the theory chapter, facts about wood are introduced, followed by literature studies and previous research. Through literature research in the university database and conducting interviews with an architect, a designer and a carpenter, data was collected for the design process and for the calculation of the dimensions for one of the selected glulam connections. The result showed that there is a lack of knowledge in Sweden regarding non-metallic connections, other countries such as Switzerland are more developed in the area and has accepted the idea of this concept. The result also showed that the lack of strength in wooden connections lead to large dimensions of the timber elements, but an aesthetic advantage can be developed. Finally, the results are discussed and analyzed according to the different requirements set on appearance, durability and manufacturability. / Detta examensarbete syftar till att utveckla kunskap om metallfria knutpunkter för att möjliggöra en mer varierad svensk träarkitektur. Den övergripande frågan har varit ”Hur väl lämpar sig metallfria knutpunkter för nutida byggande av träkonstruktioner?”. I teorikapitlet beskrivs fakta om materialet trä, följt av beskrivning av litteratur och tidigare forskning som är relevant för denna studie. Genom en litteraturstudie via universitetets databaser samt intervjuer med en arkitekt, en konstruktör och en möbeldesigner samlades data för gestaltningsprocessen och dimensionering av en knutpunkt i limträ. Resultatet visade att det finns kunskapsbrist i Sverige gällande metallfria knutpunkter, andra länder som Schweiz är mer utvecklade inom området samt har accepterat tanken på detta koncept. Resultatet visade även att frågor kring hållfasthet leder till stora dimensioner för de ingående träelementen, men att en estetisk fördel kan utvecklas. Slutligen diskuteras och analyseras resultaten utefter olika krav som ställts på utseende, hållfasthet och tillverkning.

Wood structural elements are more vulnerable to blast loading due to the inherent brittle nature and low density of the material, as demonstrated by recent significant research efforts on the behaviour of timber elements subjected to the effect of blast loading. These studies showed that wood performs poorly under blast loading. A way of improving this performance is to provide additional ductility or energy absorption capabilities to wooden elements. Recently, there was interest in investigating and developing energy-absorbing connections (EAC) to improve timber assemblies’ ductility and energy absorption capabilities. Although some research effort has been made to investigate the use of EACs to enhance the ductility of reinforced concrete or structural steel members, only limited work is available on this topic about timber elements. The current study aims to systematically investigate the use of various shapes of EACs to be used to enhance the post-peak performance of timber assemblies. Preliminary finite element analysis led to selecting nine steel EACs with varying geometries for further experimental investigation. A total of eighteen specimens were tested statically. In comparison, a total of eighteen specimens were tested dynamically in the shock tube facility of the University of Ottawa to simulate the effects of far-field blast explosions. The experimental results showed that decreasing the leg length or increasing the thickness of EACs manufactured with steel angles and reducing the diameter of EACs manufactured with circular HSS caused an increase in yield load and elastic stiffness while reducing the densification displacement. Connections with angles and a centre weld, and connections with 90-degree arcs from circular HSS, were identified as unsuitable for the application of EACs. The experimental program also showed that EACs manufactured from angles offer a well-defined plateau able to absorb a large quantity of energy, making them particularly suitable for blast mitigation. EACs manufactured from multiple circular HSS were shown to achieve multiple load-displacement plateaus and present an interesting option for systems with multiple failure modes occurring at different levels. SDOF analysis and FEA were conducted to predict the experimental behaviour with some success. The importance of the weld type was also highlighted from both the analytical and experimental results. A methodology for developing idealized load-displacement curves from experimental results of EACs was also proposed and evaluated.

Area of the airport Medlánky is situated on the border of city districts Brno-Medlánky and Brno-Komín near the nature reserve "Medlánecké kopce". The designed gallery of aviation is a two-storey building, which consists of three parts. The main part is the exhibition space for airplanes, which is formed of a single-storey long-span hall, with the two-storey entrance part of the complex of buildings connected to it, in which are situated the area of the entrance, the training center (detached workplace of the institute of aviation FS BUT in Brno) and the administration. In the building of the original hangar, which is located along the street Turistická are located restaurants and aeroclub. Exhibition hall of the building of the gallery is formed by the structural system of the arched wooden glulam beams. The load-bearing wooden structures are visible and form the elements of the interior of the exhibition space. Two-storey extention of the entrance part of the building is structurally designed as a skeleton wooden structure. The material exception is the area of the entrance, which is made of monolithic concrete.

The subject of this thesis is the construction of Sport and relaxation center in Moravany. The building is divided into three objects. The first object is Bowling & Billiard Bar. The object is single-storey with no basement, flat roof and a total built area of 602,30 square meters. The second object is Technical and operational support + Fitness. The object has two floors, no basement, flat roof and a total built area of 757,40 square meters. The third object is Restaurant. The object is single-storey with no basement, flat roof and a total built area of 602,30 square meters. The building is designed in Porotherm constructional system. Ceiling structure is designed as a monolithic concrete slab. The roof system consists of wood glued laminated beams, purlins and rafters of solid wood. The slope of the roof plane is 3 %.

This Doctoral thesis is focused on research of usability hardwood that is not used in structural engineering nowadays. Analysis of known hardwood properties and its verification by experiment was made. Mathematic analysis using the PROMETHEE method was used for most suitable hardwood species selection in the Central Europe conditions. The most suitable hardwood – beech – was subjected for further tests: finger-joint load bearing capacity experiment and beech homogenous and hybrid glulam experiment. The test results are compared with the values from professional literature.