One of the identified reasons for the low amount of timber construction in Sweden is a general lack of knowledge about timber engineering and how timber can be used to its full advantage. One way for increased timber construction is the development of a cost-efficient and easy to comprehend building system. Efficiency in construction has recently been under hot debate following the success of lean production in the manufacturing industry. Therefore, the attention of construction has been directed towards the manufacturing industry in an attempt to learn successful methods. Three main principles, modularity, lean construction, and buildability, emerge as potentially useful in order to streamline construction. The aim of this research project is to create a knowledge- based framework for long-span timber construction. This framework should be able to store knowledge and experience about timber construction as well as aid in the design and production of buildable timber structures. A buildable structure is here defined as a structure constructed in competition with all other materials and sub-system choices, i.e., by this definition a constructed structure is buildable and therefore competitive. The research is based on a case study of the design and production of long- span timber structures performed at a Swedish design company. The case study includes interviews, and a survey of 60 constructed long-span timber structures. A literature review of the industrialisation principles reveals that modularity has been a key concept in the evolution of the manufacturing industry. Therefore, the long-span timber construction industry should emit a bottom-up view where product modularity guides the construction processes. A systematic framework, Experience Feedback System (EFS), is created to store buildable construction knowledge based on modularity. The EFS is based on two distinct systems; Experience Based System (EBS), and Construction Knowledge Database (CKD), connected by a feedback loop for buildable construction feedback. The EBS utilises neural network theory containing competitive knowledge and experience of long-span timber structures, providing aid in early design. The CKS is based on the Design Structure Matrix (DSM), providing management of innovative construction and aid in detailed design. Due to the adaptability of neural networks and the developed 3-D DSM hierarchy representing the structural system, the systematic framework is potentially useful for the design and development of other types of structures and materials choices in the future. / Godkänd; 2004; 20070128 (ysko)

This thesis deals with the plastic behaviour of steel. It comprises an investigation with focus on biaxial tests and constitutive modelling. Tests were performed on one stainless steel grade in two different strength classes, C700 and C850, as well as one extra high strength structural steel grade. An earlier developed concept for biaxial testing of cross-shaped specimens was utilised. However, there was a demand for new specimen designs to enable testing of the extra high strength steel. A comprehensive test programme including an initial and one subsequent loading was carried out. This provides data for stress-strain curves in two steps as well as stress points describing initial and subsequent yield criteria. The Bauschinger effect was evident for all grades. Furthermore, the behaviour in subsequent loadings was found to be direction dependent and the transition from elastic to plastic state was observed as gradual. A constitutive model with the possibility of depicting the phenomenological observations from the tests was earlier developed at Steel Structures, LTU, and proposed for annealed stainless steels. Further, it is a two surface model utilising the concept of distortional hardening and it was applied to the steel grades tested in this work. The model was found to be applicable to the steels tested in this study as well and compared to simpler models the applied model clearly improves the agreement with experimental tests. / Godkänd; 2004; 20070131 (ysko)

The purpose of this project has been to set up a freight drawing with accompanying packages drawing for CLT-wood in the program Tekla. This is based on the requirements for freight according to the Transport Agency and what applies to handling of the CLT boards regarding the working environment hazards. Based on the problems and requests from Martinsons, this project resulted in a freight drawing with accompanying package drawing. The package drawing is going to be a helpful tool for the project manager in the manufacture of the CLT boards. The freight drawing is going to provide comprehensive information about how to load the packages on the loading platform. The project is based on a reference model called Tallbocken, which is the model that Martinsons have used before. The model is basically a building, four floors tall, made almost entirely of CLT wood. An instruction has been made, based on this model, for the establishment of freight- and package drawing. A study has been made to ensure the demands from the Transport Agency regarding the shipping of compound elements. By visiting the production line in Bygdsiljum it was clear that the staff wanted a change in how to handle the CLT boards. Information about how to handle this was also an important message on meetings with the project manager and the production staff at the fabric in Bygdsiljum. To make sure that the drawings keep in line with the recommendations, there is an explanation for the review of building documents 90’s. This working project has resulted in an instruction for how to manage the establishing of freight- and package drawing. The instruction is attached as a supplement to this essay. This instruction explains the procedure step by step for how to create a freight drawing for CLT wood in Tekla structures by using a complete project template. / Syftet med detta projekt har varit att få en mer klar bild över vad som gäller, och hur man från en färdig projektmodell kan ta fram en frakt- samt paketritning för KL-trä i Tekla. Detta utifrån de krav transportstyrelsen ställer vid frakt, samt vad som gäller vid hanteringen av skivorna med avseende på arbetsmiljörisker. Utifrån de problem och önskemål personalen på Martinsons ser, har en fraktritning med tillhörande paketritning tagits fram. Paketritningen är tänkt att fungera som underlag för produktionsledaren vid tillverkningen av skivorna. Fraktritningen ska ge en större blick över hur dessa paket sedan ska lastas på flaket. Projektet har utgått från en referensmodell kallad Tallbocken som Martinsons tidigare arbetat med. Modellen är en fyra våningar hög byggnad till största delen gjord av KL-trä. Utifrån denna har en instruktion för upprättandet av frakt- samt paketritning tagits fram. För att transportstyrelsens krav vid frakt av sammansatta element ska säkerställas har en studie över detta gjorts. Det har även via besök vid produktionslinjen i Bygdsiljum framkommit de problem personalen ser vid hanteringen av KL-skivorna. Utöver detta har information om hanteringen framkommit genom medverkande på möten med projektledare samt produktionspersonal vid fabriken i Bygdsiljum. För att ritningarna i slutändan ska hålla sig till de rekommendationer som finns framtagna har en genomgång av bygghandlingar 90:s krav förklarats. Arbetet resulterade i en instruktion för hur upprättandet av en frakt- och paketritning kan genomföras. Instruktionen bifogas som bilaga i rapportens slut. Denna förklarar steg för steg tillvägagångssättet, att från en färdig projektmodell skapa en fraktritning för KL-trä i Tekla

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Today housing and service accounts for 40 % of Swedens total final energy usage.Buildings have a very long lifespan and the energy-related decisions taken todayaect both costs and the environment for decades to come. Therefore, the NationalBoard of Housing, Building and Plannings building regulations require thatenergy verification be carried out on buildings within two years after completionof construction. Bromma Airport Arrival Hall B93 underwent extensive rebuildingand was reopened in the fall of 2017. Therefore, on behalf of Ramb¨oll, an energyperformance verification has been carried out for the building. The energy performanceverification has been carried out in the form of a masters degree project inenergy engineering at Umeå University. Energy verification can be performed bymeasurement/normalization or calculation, in this case, energy performance verificationwas done through calculations using IDA ICE software. During the project itwas required that certain delimitations were made due to lack of access to premisesand lack of documentation but through assumptions energy performance verificationcould be accomplished. The results shows that the building meets the energyperformance requirements from the National Board of Housing, Building and Planningsbuilding regulations (BBR).The project also included project targets beyond a conventional energy performanceverification. In addition to the energy performance verification, the project containeda comparison between the energy calculation submitted for the planning applicationfor the rebuilding with the energy calculation for the energy performanceverification. Any deviations were to be identified and explained. In addition, additionalenergy performance requirements were to be identified. The simulated modelsfrom the planning application and the energy performance verification showeda dierence in both outwards appearance and heating-, ventilation- and sanitationsystems. The report includes a detailed explaination of the comparison. Swedavia,owner of the property, proved to have internal energy requirements for its buildings.These are presented in detail in the report, and the results of the project shows thatthe building also reaches these requirements.

In the last decade, the use of cross-laminated timber (CLT) panels as load bearing elements have become a usual solution for buildings and structures with an upward trend internationally. This is because CLT has brilliant physical and mechanical properties and it is also an eco-friendly and renewable material. In addition, the prefabricated nature of the CLT panels in a controlled environment increases the overall building speed, reduces dramatically the erection time, and makes it an even more competitive structural material compared to more traditional ones like concrete and steel. Up until now, timber as a building material has mainly been used for roofs and pergolas in Greece. Concrete and steel have traditionally been the dominant building materials over the years. Timber is not such competitive mainly because there is not enough knowledge of abouttimber buildings. The fact that Greece is not a sawn timber producer affects this trend. Nowadays, the simple and cheap import of sawn timber, as well as the sensitiveness about the environment, are strong factors for introducing timber buildings to Greece. There is already a great demand for timber buildings, and an increase in the requests is expected.CLT panels are used in a wide spectrum of structural applications. They are used as structural components for houses, offices, multi-story buildings, schools, industrial halls, sports halls, and special structures [4]. Another innovative application of CLT is the renovation through vertical expansion with additional floors to existing buildings. This new and promising trend is becoming more and more frequent, especially in developing cities where there is a need for new houses in limited space. The low density of CLT and so the low overall weight of the additional structure, makes the CLT components a robust building solution for vertical renovation since there is usually no need for reinforcement of the foundations of the current building [15]. The aim of this study is to provide the author with the opportunity to deepen his knowledge regarding the special characteristics of CLT as a building material as well as to understand its mechanical properties and the theories which describe them. In addition, this study constitutes the first attempt at modeling and designing a timber structure made with CLT panels. Therefore, the knowledge gained about the special features in CLT modeling is a fundamental task. Finally, since the design of the CLT structure is based on the European design rules for buildings, the engagement with the appropriate Eurocodes, i.e. Eurocode 0, 1 & 5, is another critical task in this study. The structure under consideration is a two-story CLT structure which is a vertical expansion of a current composite (concrete-steel) building. The first additional floor will be used as an office area and the second one as a typical family house. Both additional floors are made of CLT elements and, where is necessary, glulam beams and columns are considered as reinforcement of the CLT panels and as supports, respectively. The design method includes finite element analysis (FEA) which is performed by the commercial structural softwareDLUBAL – RFEM [8]. In this study, the latter software is chosen for the design and the analysis of the structure since it is specialized software for timber structures made of CLT elements.

Förkonstruerade byggnader som begrepp syftar till att byggnaden är projekterad innan någon köpare är känd. Detta innebär att tekniska lösningar med tillhörande produktionsmetoder är utvecklade innan avtal sluts. Denna metodik tillämpas inom "Metal Building Systems Industry", eller "Pre-engineered Buildings Industry", i USA. I den första delen av detta arbete studeras denna industri genom en utvärderande surveyundersökning som syftar till att utvärdera om förkonstruerade byggnader kan vara ett medel att effektivisera den svenska byggprocessen vid nyproduktion av flerbostadshus. Den andra delen är en studie av brukarnas uppfattningar om sitt boende. Denna studie utförs med hjälp av källanalys och syftar till att bestämma vilka frihetsgrader som behöver finnas med vid utformandet av ett datasystem för förkonstruerade byggnader. Arbetet innehåller även ett räkneexempel på vad en investering i ett datasystem för förkonstruerade byggnader skulle kunna innebära för ett svenskt byggföretag. / <p>Godkänd; 1998; 20070404 (ysko)</p>

Development of steel frame modular buildings is gaining increased popularity and support throughout Europe. Due to flexibility in construction and good long-term performance, lightweight steel frame structures are often preferred solutions, for instance in partitions and suspended ceilings as well as for load-bearing elements. In many applications the steel frame structure are required, indirectly or directly, to have a certain fire resistance performance. There is still knowledge to be gained in order to accomplish efficient rules for assessment of the behaviour of lightweight steel frames in fire situations. The lack of such rules creates a disadvantage for the elements since they will require additionally costly protection measures, or to perform expensive fire tests. The problem is more pronounced for load-bearing structures. This makes design by testing a rather inefficient method. Therefore, it is important to develop economical design rules at elevated temperature for possible implementation in Eurocode 3. The main objectives of the thesis is to evaluate FE-models for analysis of thin-walled steel columns and to compare the results with experiments at room temperature and at elevated temperatures. The main contribution of the work is to recommend the design model for a possible implementation in Eurocode 3, Part 1-2. The design model includes possibility of flexural and torsional-flexural failure mode. It contemplates thermal deflection, reduced yield strength and elastic modulus and is evaluated on studs with a constant temperature (symmetric heating) and with a temperature gradient (unsymmetrical heating). Constant temperature distribution is assumed along studs in both cases. / <p>Godkänd; 2004; 20070126 (ysko)</p>

<p>Godkänd; 1999; 20070404 (ysko)</p>

One of the reasons for the low amount of timber in construction is a general lack of knowledge about timber engineering and how timber can be used to its full advantage. In this thesis the focus is 3D computer visualisation (3D VIZ) of non-residential long-span timber structures, used for storage, industry and sports where 3D VIZ is defined as a process where a 3D-model is enhanced with environmental information e.g. texture maps and realistic light effects. An area of interest is the possibilities to increase timber construction through communicating the aesthetical properties of an exposed timber structure through using 3D VIZ. The aim of this exploratory study is to develop a foundation for future theory building through analysing the construction process and its use of communication media with respect to communication theory and media richness. The study further proposes how the communication process of long-span timber structures can be enhanced by using 3D VIZ and identifies connections between the construction process, participants and project classification. In this thesis two major research strategies have been utilised, a case study and a survey. The first research strategy includes a cross-industry learning research setting, using two case studies, applied and analysed regarding industrial design and architecture. The case studies suggest that a practice of concurrent engineering (CE) in construction and frequent use of 3D-computer visualisation by integrated product teams (IPT) can help to enhance the aesthetical value of the final building. The case studies also confirm that 3D VIZ is useful as a communication tool in the construction industry and demonstrate that using 3D VIZ during the planning process affects the image of the final result created by those involved. The second research strategy includes an Internet-based survey where the usefulness of 3D VIZ during the construction process is evaluated. The results show that structural complexity, intended viewer and current building phase influence the benefit of 3D VIZ. A number of parameters needed to communicate the aesthetics of timber efficiently, i.e. textures, surface structures, true dimensions and realistic light effects, have been pointed out. The analysis regarding communication theory and media richness indicate that the need for rich media, 3D VIZ with high realism and high level of detail (LOD), is generally higher for external communication compared to internal communication between professionals. The need for rich media is also high in the beginning of every new phase, while the need will decrease in the end of the phase. / Godkänd; 2005; 20061221 (haneit)