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)

In recent years indoor environment and indoor air quality has been subjected to extensive worldwide research efforts. Still, at present there are a lack of methods for prediction of risks and consequences for any defined damage to occur, similar to the probabilistic methods used in modern design codes for structures and buildings. Such a method, if available and usable, could be very beneficial as a tool for decision making at different stages of the building process. In this licentiate thesis a method is developed to estimate the risk of occurrence of high radon concentrations indoors. The method is developed using risk analysis applied on a concrete slab on the ground, which is a foundation method commonly used in Sweden for residential buildings. The undesirable event is "Leakage of radon into the building" and fault tree analysis is used starting in the top with the undesirable event and then working downwards finding the events, which causes the top event. This procedure continues until basic events are established and for which failure probabilities are available. Fault tree analysis is a deductive method mainly used for systems built up with electronic equipment where failure probabilities in terms of relative frequency are easy to establish. Failure probabilities are more difficult to establish in the building process since failures are rare. However, this uncertainty can be handled by applying structural reliability analysis on the quantitative analysis whereas several random variables can be taken into account in a single analysis, which makes it possible to analyse a whole branch of a fault tree in a single analysis. The basis for structural reliability methods is probability theory to handle the uncertainties and Monte Carlo simulation and first-order second-moment theory to estimate the risk. To get an indoor environment that is unhealthy to human beings environmental impact is needed together with fault due to human error in some phase of the building process. Examples of faults made in the building process are changes and/or addition of work ordered by the proprietor, unsuitable design or delivery of wrong material to the construction site. Several surveys have come to the same conclusion that a large amount of faults made in the building process depends on e.g. insufficient commitment or lack of knowledge. However, the building could be designed and constructed according to the state-of-the art of knowledge and still has an improper function. Errors cannot be ruled out completely but the use of fault tree technique to develop the causes to an unhealthy indoor environment and the estimation of risk can be a valuable communication tool to the quality management system to get an overview of the entire building process and to identify the week links. The residential building used as an example in this work is situated outside the municipality of Linköping since long-term measurements of radon concentrations in soil air are available from this area. The building has a self-draught ventilation system and the design of the concrete slab, starting from the excavated rock floor, include a geotextile, 150 mm well washed macadam, 50 mm insulation, 100 mm reinforced concrete, a levelling compound and finally a flooring. The causes to radon concentrations indoor has been developed with fault tree analysis where "Leakage of radon contaminated soil air into the building", "Radon contaminated drinking water" and "Building material contains radium disintegrating to radon" constitute the main causes. The event "Leakage of radon contaminated soil air...." is developed further, since it is the major contributor to radon concentrations indoor, into the events "Lower air pressure indoor than outdoor", "Radon contaminated soil air under or around the building" and "Fault in component with regard to air-tightness". A function expressing the relationship between the basic events and their random variables is established and both Monte Carlo simulation and first-order second-moment theory is applied to estimate the probability and the safety index b for the undesirable event to occur. The leakage of radon-contaminated soil air has only been considered through fissures in the concrete slab and it has been difficult to find proper relationships between how fissures occur, fissure width, and concrete and reinforcement properties. Approximations have therefore become necessary. However, the simulation and the analytical calculation gives e.g. safety index beta = 0.30 on normal risk area, which is 70 % of the total area of Sweden, in residential buildings where people stay more than temporary. Comparison can be made with the safety index beta larger or equal to 4.3 for safety class 2 in the Swedish Design Regulations for the structure of residential buildings. In a residential building on normal risk area and designed in accordance with the concrete slab in this work, the probability for radon concentrations indoor to exceed the Swedish Building Regulations threshold value 200 Bq/m3 is over 40.000 times larger than the risk for structural failure. / Världen över bedrivs det omfattande forskning på inomhusmiljö och luftkvalitet. Trots det finns det fortfarande ingen metod för att bestämma sannolikheten för att någon form av definierad skada inträffar på inomhusmiljön med konsekvenser för människors hälsa på samma sätt som det finns metoder i moderna konstruktionsregler för att bestämma risken för mekanisk påverkan på byggnadskonstruktioner. Förekomsten av en sådan metod skulle vara ett viktigt instrument för miljöbeslut i alla led i byggprocessen.En metod har utvecklats i denna licentiatuppsats för att bestämma risken för att höga koncentrationer av radon skall förekomma i inomhusluften. Metoden har tagits fram genom att tillämpa riskanalys på en platta på mark som är en vanlig handläggningsmetod för bostadshus i Sverige. Orsakerna till den oönskade händelsen "Läckage av radon in i byggnaden" har kunnat härledas med hjälp av felträdsanalys genom att starta i toppen av trädet och arbeta sig nedåt. Proceduren upprepas tills primärhändelser erhålls för vilka sannolikheter kan bestämmas. Felträdsanalys är en deduktiv metod som är utvecklad för system som är uppbyggda av elektroniska komponenter och för vilka sannolikheter för fel i form av relativa frekvenser är enkla att bestämma. Det är svårare att bestämma sannolikheter för fel i byggprocessen eftersom varje objekt oftast är unikt. Denna osäkerhet kan dock hanteras genom att använda samma säkerhetsfilosofiska modell som används för mekanisk påverkan på bärande konstruktioner där hänsyn kan tas till flera stokastiska variabler i samma analys vilket gör det möjligt att ersätta en hel gren i ett felträd. För att hantera osäkerheter används den säkerhetsfilosofiska modellen för bärande konstruktioner sannolikhetsteori och för att bestämma risken kan Monte Carlosimuleringar och 'första ordningens nivå 2'-metod användas.För att få en ohälsosam inomhusmiljö behövs miljöpåverkan tillsammans med ett fel i byggnaden orsakat i något led av byggprocessen. Exempel på fel som kan medföra en ohälsosam inomhusmiljö är att byggherren ändrar eller gör kompletteringar i byggnaden, konstruktionen är olämpligt utförd eller att materialleveranser är felaktiga. Flera undersökningar har kommit fram till att t.ex. bristande engagemang eller bristande kunskap många gånger är orsakerna till de fel som uppkommer i byggprocessen. Bristande kunskap kan också bero på att kunskapen inte finns, dvs byggnaden utförs på ett riktigt sätt med avseende på den kunskap som finns. Fel kan aldrig elimineras helt men användandet av felträdsanalys för att ta fram orsakerna till en ohälsosam inomhusmiljö och bestämmandet av risken skulle kunna vara ett värdefullt verktyg i kvalitetssystem för att få en överblick över hela byggprocessen och för att kunna identifiera de svaga länkarna.Bostadshuset som exemplifieras i den här uppsatsen är beläget utanför Linköping eftersom det där har förekommit långtidsmätningar på radonhalten i marken. Byggnaden ventileras genom självdrag och grundplattans konstruktion består, med start från schaktbotten, av en geotextil, 150 mm vältvättad makadam, 50 mm isolering, 100 mm armerad betong, avjämningsmassa samt golvbeläggning. Orsakerna till radonkoncentrationer inomhus har bestämts genom felträdsanalys och består av "Läckage av radonhaltig jordluft", "Radonhaltigt dricksvatten" och "Byggnadsmaterialet innehåller radium som sönderfaller till radon". Den huvudsakliga orsaken till radon i inomhusluften är "Läckage av radonhaltig jordluft" och den utvecklas därför vidare och orsakas av "Lägre lufttryck inomhus än utomhus", "Jordluften under eller runt byggnaden innehåller radon" och "Fel i byggnadsdelen med hänsyn till lufttäthet". En funktion som beskriver förhållandet mellan de olika primärhändelserna och dess stokastiska variabler har tagits fram och genom att använda både Monte Carlo-simulering och första ordningens nivå 2-metod har sannolikheten samt säkerhetsindex β bestämts för att den oönskade händelsen skall inträffa.Hänsyn har bara tagits till läckage av radonhaltig jordluft genom sprickor i betongplattan och det har varit svårt att hitta lämpliga förhållanden mellan hur sprickor uppkommer, sprickvidd och betongens och armeringens egenskaper. Därför har antaganden gjorts i vissa fall. För normalriskmark, som 70 % av Sveriges yta består av, har simuleringarna och beräkningarna givit ett säkerhetsindex β = 0.30 för bostadshus där människor uppehåller sig mer än tillfälligt. En jämförelse kan göras med de svenska konstruktionsreglerna där bärande konstruktioner i ett bostadshus skall uppfylla säkerhetsklass 2 med ett säkerhetsindex β ≥ 4.3 för att ett bostadshus, byggt på normalriskmark med en platta på mark enligt denna uppsats, skall innehålla radonkoncentrationer över det svenska normgränsvärdet 200 Bq/m3, är alltså mer än 40.000 gånger större än risken för att den bärande konstruktionen inte skall hålla. / <p>Godkänd; 2003; 20070217 (ysko)</p>