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  • 301.
    Olsson, Anders
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Oscarsson, Jan
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Strength grading based on high resolution laser scanning: performance of a procedure newly approved for the European market2015In: Proceedings of the 19th International Nondestructive Testing and Evaluation of Wood Symposium / [ed] Ross, Robert J.; Goncalves, Raquel; Wang, Xiping, Madison, USA: USDA, United States Department of Agriculture, Forest Service, Forest Products Laboratory , 2015, Vol. 19, p. 232-240Conference paper (Refereed)
    Abstract [en]

    Strength grading of timber is necessary to ensure sufficient structural performance of the material, and machines based on different types of non-destructive measurements are available on the market. The purpose of this paper is to present results on an investigation of a new method and procedure for machine strength grading that is based on laser scanning and utilization of the tracheid effect, in combination with dynamic excitation and weighing. The investigated sample comprised more than 900 pieces of timber of Norway spruce (Picea abies) from Sweden, Norway and Finland. The coefficient of determination between the indicating property (IP) to bending strength and the measured bending strength was as high as R2 = 0.69, while the coefficient of determination between dynamic MOE and measured bending strength was R2 = 0.53. A comparison of the performance with what have been presented for machines that are based on X-ray in combination with dynamic excitation indicates that the new method/procedure will surpass such machines. 

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  • 302.
    Olsson, Anders
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Oscarsson, Jan
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Strength grading on the basis of high resolution laser scanning and dynamic excitation: a full scale investigation of performance2017In: European Journal of Wood and Wood Products, ISSN 0018-3768, E-ISSN 1436-736X, Vol. 75, no 1, p. 17-31Article in journal (Refereed)
    Abstract [en]

    Effective utilization of structural timber requires grading and indicating properties (IPs) that are able to predict strength with high accuracy, and machines that are able to measure the underlying board properties at a speed that corresponds to the production speed of sawmills. The aim of this research is to assess the performance of a new machine strength grading method/procedure which was recently approved for the European market and to compare the performance of it with the performance of other available techniques. The novel method is based on laser scanning utilizing the tracheid effect, in combination with data from dynamic excitation and weighing. Applied indicating properties are defined in detail and results presented include assessment of the repeatability, coefficients of determination between IPs and grade determining properties, and examples of the yield achieved in different strength classes and combinations of strength classes. The investigated sample comprised more than 900 pieces of timber of Norway spruce (Picea abies) from Sweden, Norway and Finland. For this sample the coefficient of determination between the IP to bending strength and the measured bending strength was as high as R2 = 0.69, while the coefficient of determination between dynamic modulus of elasticity (MOE) and measured bending strength was R2 = 0.53. The yield in high strength classes, C35 and above, become about twice as high using the new method/procedure compared to machines using dynamic MOE as IP. A comparison of the performance with what have been presented for machines that are based on X-ray in combination with dynamic excitation indicates that the new method/procedure will surpass such machines as well. 

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  • 303.
    Olsson, Anders
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Oscarsson, Jan
    SP Technical Research Institute of Sweden, Sweden.
    Three dimensional fibre orientation models for wood based on laser scanning utilizing the tracheid effect2014In: Proceedings of the 2014 World Conference on Timber Engineering (WCTE), Quebec City, Canada, August 10−14, 2014, 2014Conference paper (Refereed)
    Abstract [en]

    Recentresearch has shown that machine strength grading based on tracheid effectscanning of fibre directions projected on board surfaces can provide moreaccurate strength predictions than today’s grading methods. Scanning techniquesin which 3D fibre orientations can be taken into account would most likelyimprove the strength grading results even further. In this investigation thepossibility of determining such 3D orientations by dot laser scanning wasinvestigated. For a set of 20 side boards, scanning data was used to calculatetraversing knot directions which were in turn applied to determine pithlocation and root end of original logs. By means of the shape of laser dots,which due to the tracheid effect are turned elliptic on board surfaces, and thedetermined pith location, the size and direction of the diving angle of thefibres was calculated. The research showed that this angle can be accuratelydetermined in the vicinity of knots.

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  • 304.
    Olsson, Anders
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Pot, Guillaume
    LaBoMaP, France.
    Viguier, Joffrey
    LaBoMaP, France.
    Faydi, Younes
    LaBoMaP, France.
    Oscarsson, Jan
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Performance of strength grading methods based on fibre orientation and axial resonance frequency applied to Norway spruce (Picea abies L.), Douglas fir (Pseudotsuga menziesii (Mirb.) Franco) and European oak (Quercus petraea (Matt.) Liebl./Quercus robur L.)2018In: Annals of Forest Science, ISSN 1286-4560, E-ISSN 1297-966X, Vol. 75, no 4, article id 102Article in journal (Refereed)
    Abstract [en]

    Key messageMachine strength grading of sawn timber is an important value adding process for the sawmilling industry. By utilizing data of local fibre orientation on timber surfaces, obtained from laser scanning, more accurate prediction of bending strength can be obtained compared to if only axial vibratory measurements are performed. However, the degree of improvement depends on wood species and on board dimensions. It is shown that a model based on a combination of fibre orientation scanning and axial vibratory measurement is very effective for Norway spruce (Picea abiesL.) and Douglas fir (Pseudotsuga menziesii(Mirb.) Franco). For European oak (Quercus petraea(Matt.) Liebl./Quercus roburL.) boards of narrow dimensions, axial vibratory measurements are ineffective whereas satisfactory results are achieved using a model based on fibre orientation.ContextMachine strength grading of sawn timber is an important value adding process for the sawmilling industry.AimsThe purpose of this paper has been to compare the accuracy of several indicating properties (IPs) to bending strength when applied to Norway spruce (Picea abies L.), Douglas fir (Pseudotsuga menziesii (Mirb.) Franco) and European oak (Quercus petraea (Matt.) Liebl./Quercus robur L.).MethodsThe IPs were determined for a set of data comprising scanned high-resolution information of fibre orientation on board surfaces, axial resonance frequency, mass and board dimensions.ResultsWhereas dynamic axial modulus of elasticity (MoE) gave good prediction of bending strength of Norway spruce (R-2=0.58) and Douglas fir (R-2=0.47), it did not for narrow dimension boards of oak (R-2=0.22). An IP based on fibre orientation gave, however, good prediction of bending strength for all three species and an IP considering both dynamic axial MoE and local fibre orientation for prediction of bending strength gave very good accuracy for all species (Norway spruce R-2=0.72, Douglas fir R-2=0.62, oak R-2=0.59). Comparisons of results also showed that scanning of fibre orientation on all four sides of boards resulted in more accurate grading compared to when only the two wide faces were scanned.ConclusionData of local fibre orientation on wood surfaces give basis for accurate machine strength grading. For structural size timber of Norway spruce and Douglas fir, excellent grading accuracy was achieved combining such data with data from vibratory measurements. The improvements achieved enable substantial increase of yield in high-strength classes.

  • 305.
    Olsson, Anders
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Serrano, Erik
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Oscarsson, Jan
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Enquist, Bertil
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Johansson, Marie
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Källsner, Bo
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Förfarande och anordning för utvärdering av en bräda av trä2014Patent (Other (popular science, discussion, etc.))
    Abstract [sv]

    Föreliggande redogörelse avser en metod och en anordning för utvärdering av en bräda av trä med en ländriktning. Data som indikerar fiberorienteringen över brädans yta inhämtas och för ett antal underpartier hos brädan bestäms en nominell, lokal elasticitetsmodul, MOE, på basis av nämnda fiberorienteringsdata och en nominell materialparameter. En nominell global MOE i längdriktningen för träbrädan i sin helhet genereras och jämförs med en sekundär global MOE. På basis av nämnda fiberorienteringsdata och denna jämförelse genereras en uppskattad lokal elasticitetsmodul, MOE, i nämnda längdriktning för ett flertal underpartier. Dessa data kan användas för exempelvis tillförlitlig hållfasthetsgradering av träbrädor.

  • 306.
    Olsson, Andreas
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Spetz, Kajsa
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Den multifunktionella byggnadens roll i ett socialt hållbart kvarter2020Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This study focuses primarily on social sustainability, which is a large and comprehensive concept. In today's urban planning, social sustainability is used on a broader perspective. The study aims to focus more on the concept for individual multifunctional buildings by gathering knowledge about the subject and highlight the meaning. The chosen multifunctional buildings are Icon in Växjö and Spektrum in Gothenburg.

    The purpose of this study is, through research and evaluation, to concretize people's daily needs and how they can be met in a multifunctional building and its contribution to a socially sustainable neighbourhood. The goal is to get a better understanding of which impact the multifunctional building has on its block. The goal is also designing and application of a tool developed in the context of the current study and to use this tool to evaluate the building's social sustainability based on people's everyday lives, needs and interests.

    Interviews with responsible project managers, architects, supervisors and other experts, together with the gathering of scientific reports, study visits, questionnaires and observations, has been the studies central approach.

    Working towards a more mixed urban environment and buildings that have different operation that are combined is nowadays increasingly common for a livelier and more enjoyable urban space. Based on the study´s designed tool, each multifunctional building has received different social points that depends on size, operations, availability and multifunctionality. The study shows that each multifunctional building has added value to its area.

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    Den multifunktionella byggnadens roll i ett socialt hållbart kvarter
  • 307.
    Olsson, Erika
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Abrahamsson, Jenny
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Utökade krav för svetsade stålkonstruktioner vid efterbehandling av svetsar2019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The steel industry stands for 7 % of the worlds emission of carbon dioxide. An alternative to reduce the environmental impact of the industry is to introduce structures of high strength steel since it provides opportunity for slimmer structures and thereby less material consumption. However, the use of high strength steel in welded structures can be problematic when exposed to fatigue loads, which can lead to unsuspected breaks in the structure. To improve welded structures against fatigue PWT can be implemented.The possibilities for implementation of PWT during manufacturing and possible obstacles as to why it should not be used was investigated in this thesis. To form a perception for the possibilities of alternative welding methods to increase fatigue strength the existing regulations and norms of execution for as welded conditions was examined. Opinions from different participants in the construction process were interviewed to answer the questions at issue.The lacking ability to verify stress in a weld was concluded to be a contributing factor as to why PWT is not currently used during the manufacturing process in the construction industry. The interview with Trafikverket resulted in the alternative to create a specific requirement specification according to demands in Krav Brobyggande. Approval of the specific requirement specification could lead to possibility to implement PWT in the construction industry. Krav Brobyggande is Trafikverkets document with demands and advice for bridge construction in Sweden.

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  • 308.
    Ormarsson, Sigurdur
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Moisture-induced stresses in curved statically indeterminate timber structures2015In: Theoretical, Numerical, and Experimental Analyses in Wood Mechanics, 2015Conference paper (Refereed)
  • 309.
    Ormarsson, Sigurdur
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Parameterized and adaptive modelling of structural behaviour of innovative modular-based multi-storey timber buildings of wood2018In: Presented at EMI 2018, Engineering Mechanics Institute Conference, May 29 - June 1, 2018, MIT, Cambridge, USA, 2018Conference paper (Refereed)
  • 310.
    Ormarsson, Sigurdur
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Dahlblom, Ola
    An extended beam model for simulation of hygro-mechanical and visco elastic deformations in inhomogeneous timber structures2014In: 11th World Congress on Computational Mechanics - 2014, Barcelona: Spanish Association for Numerical Methods in Engineering , 2014Conference paper (Refereed)
    Abstract [en]

    Due to numbers of failures of large glue laminated (glulam) timber structures there seems to be a need for better design tools for wood applications. In EC5 and in many textbooks on timber design it is stated that the moisture sensitivity of the wood material needs to be taken into account in the design process. But the fact is that in stress calculations associated with ordinary timber design, these matters are not dealt with properly. The problem is that it is very difficult to predict the variation of moisture-related stresses during the service life of the timber structure as a whole. A proper prediction requires that material inhomogeneity, mechano-sorption effect and visco-elastic behaviour are taken into account. The paper presents a finite element implementation of a new beam element able to simulate hygro-mechanical and visco-elastic behaviours in inhomogeneous timber structures.

  • 311.
    Ormarsson, Sigurdur
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Gislason, Oskar V.
    Technical University of Denmark, Denmark.
    Moisture-induced stresses in glulam frames2016In: European Journal of Wood and Wood Products, ISSN 0018-3768, E-ISSN 1436-736X, Vol. 74, no 3, p. 307-318Article in journal (Refereed)
    Abstract [en]

    Wood is a hygroscopic and moisture-sensitive material that seeks to achieve equilibrium moisture content (EMC) with its surrounding environment. For softwood timber structures exposed to variations in climate throughout their service life, this behaviour results in variable moisture-content gradients that cause moisture-induced stresses in the direction of and perpendicular to the fibres. Although Eurocode 5 (EC5) states that moisture-induced stresses should be considered, they are often not adequately dealt with in building design due to the difficulties in predicting the stresses involved by hand. Accordingly, there is a need for advanced computer tools to study how the long-term stress behaviour of timber structures is affected by creep and cyclic variations in climate. A beam model to simulate the overall hygro-mechanical and visco-elastic behaviour of (inhomogeneous) glulam structures is presented. A two-dimensional transient, non-linear moisture transport model for wood is also developed and linked with this beam model. The combined models are used to study the long-term deformations and stresses in a curved frame structure exposed to both mechanical loading and cyclic climate conditions. It is shown that the moisture-induced deformations and stresses are of such magnitude that the design codes employed should take them into account. Thus it is argued that climate-related loads should be treated as separate load contributions that can be included in different load combinations.

  • 312.
    Ormarsson, Sigurdur
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Johansson, M.
    Numerical simulations of structural behaviour of volume modules used for construction of multifamily timber houses2017In: CompWood 2017 : Computational Methods in Wood Mechanics – from Material Properties to Timber: Programme & Book of abstract, 2017Conference paper (Refereed)
  • 313.
    Ormarsson, Sigurdur
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Johansson, Marie
    SP.
    FE-modell av en volymmodul - spännings- och stabilitetsanalys : Förstudie2017Report (Other academic)
    Abstract [sv]

    Trä är ett mycket användbart, prisvärt och förnyelsebart material som rätt utnyttjat har en extremt hög industriell potential inom området byggnadskonstruktion. Det finns ett stort intresse i Sverige att utforska nya sätt att utnyttja trä som huvudlastbärande material i olika typer av flervåningshus. Detta är en stor utmaning för träbyggnadsindustrin, forskare och konstruktörer eftersom det inte finns någon traditionell beräknings- och designprocedur för dessa typer av byggnader.

    I denna förstudie har en parametrisk FE-modell framtagits för att studera strukturmekaniska egenskaper (deformationer och styvhet) hos en typisk volymmodul som används för byggande av flerbostadshus i trä. Modellen är uppbyggd av olika typer av strukturelement (fjädrar, balk- och skalelement) för att den skall vara så snabb och flexibel som möjligt. Modellen inkluderar ett stort antal konnektor- och kopplingselement för att på ett optimalt sätt kunna simulera alla spik-, skruv- och bultförband i modulen. Modellen är också ganska flexibel eftersom den är parameterstyrd via ett antal geometriska parametrar. Modellen har använts för att studera globala deformationer och styvhetsegenskaper hos olika vägg- och volymelement när de belastas med olika mekaniska laster. Att få en uppfattning om hur styvhetsegenskaper hos de mekaniska förbanden (svaga delar i konstruktionen) påverkar det globala deformationsbeteendet hos olika vägg- och volymelement har varit en viktig del i denna förstudie.

    Modellen visar ett deformationsbeteende hos vägg- och volymelementen verkar rimliga men en experimentell verifiering återstår. Ett exempel på resultat är att väggelement som belastas i planskjuvning har en tydlig tendens att böja ut ur planet eftersom det finns gipsskiva enbart på insidan av regelstommen. Studien visar också att för volymmoduler med en gles skruvförbindning mellan vägg- och bjälklagselementen uppkommer stora gliddeformationer mellan elementen. En av de viktigaste slutsatser från denna förstudie är att det gick att skapa en snabb och effektiv strukturmekanisk tredimensionell FE-modell för den här typen av konstruktion. Beräkningstiden för en volymmodul var endast 5.5 minuter på en vanlig laptop computer. Dessa resultat visar därför att det finns goda förutsättningar för att kunna simulera och analysera hela flerbostadshus inom rimliga beräkningstider.

  • 314.
    Ormarsson, Sigurdur
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Johansson, Marie
    RISE Research Institute of Sweden, Sweden.
    Finite element simulation of global structural behaviour of multifamily timber buildings using prefabricated volume modules2018In: WCTE 2018 - World Conference on Timber Engineering, World Conference on Timber Engineering (WCTE) , 2018Conference paper (Refereed)
    Abstract [en]

    The potential of building multi-storey timber buildings has changed in recent decades. The building of apartment houses with fully prefabricated volume modules in wood is an industry sector that is rapidly increasing its capacity. A number of house manufacturers that have delivered volume modules, primarily for single family homes, are now expanding their production to multi-storey buildings up to 6-8 floors. This is a challenging task for producers, since the available design procedures for timber buildings have not yet been fully implemented for these types of buildings.The aim of the work is to develop an efficient and flexible finite element model to analyse the three-dimensional structural behaviour of multi-storey buildings using prefabricated volume modules made by wooden stud-and-rail structure. The model will be used to study the global structural behaviour of various timber walls, volume modulus and modular-based multi-storey buildings when subjected to different types of loading. The model will also be used for detailed analysis and design (using so-called adaptive modelling) of the most critical (weak) parts of the structure.

  • 315.
    Ormarsson, Sigurdur
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Steinnes, Jan Roar
    Norcunsult AS, Norway.
    An enhanced beam model for glued laminated structures that takes moisture, mechano-sorption and time effects into account2014In: WCTE 2014 World Conference on Timber Engineering, Quebec City, Canada, August 10-14, 2014 / [ed] Alexander Salenikovich, Quebec City: Université Laval , 2014Conference paper (Refereed)
    Abstract [en]

    There is a need of more advanced analysis for studying how the long-term behaviour of glued laminated timber structures is affected by creep and by cyclic variations in climate. A beam theory is presented able to simulate the overall hygro-mechanical and visco-elastic behaviour of (inhomogeneous) glulam structures. Two frame structures subjected to both mechanical and cyclic environmental loading are analysed to illustrate the advantages the model involved can provide. The results indicate clearly both the (discontinuous) inhomogeneity of the glulam products and the variable moisture-load action that occurs to have a significant effect on deformations, section forces and stress distributions within the frame structures that were studied.

  • 316.
    Ormarsson, Sigurdur
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Vessby, Johan
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Geometric nonlinear analysis of a pitched roof structure of wood2016In: Eccomas 2016 Proceedings, 2016Conference paper (Refereed)
  • 317.
    Ormarsson, Sigurdur
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Vessby, Johan
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Källsner, Bo
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Filchev, Ivan
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Numerical analysis of failure modes and force distribution in a pitched roof structure of wood2016In: Proceedings of the 2016 World Conference on Timber Engineering (WCTE) / [ed] J. Eberhardsteiner, W. Winter, A. Fadai, M. Pöll, Vienna: Vienna University of Technology , 2016Conference paper (Refereed)
    Abstract [en]

    Instability failures of timber elements and timber structures are reported relatively frequently although there are some suggestions available how to prevent such failures. These types of failures are characterized by sudden deformations that typically lead to failure in a single loadbearing element or collapse of the entire structure. This paper deals with buckling analysis and geometric nonlinear stress analysis of pitched roof structures of wood. A FE- model has been developed and used to study how different parameters influence the buckling modes and force distribution in the lateral bracing system of the roof structure. The simulated forces in the bracing system are also compared with results based on a simple design method given in Eurocode 5 (EC5) and a method where the compressed top chord is treated as a beam on a continuous elastic foundation. The buckling simulations showed the out-of-plane buckling to be the critical failure mode for the truss structure studied and the geometric nonlinear analysis showed the bracing stiffness and the bracing forces to be significant lower than those calculated by hand according to EC5.

  • 318.
    Oscarsson, Jan
    et al.
    SP Technical Research, Institute of Sweden, Växjö.
    Olsson, Anders
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Enquist, Bertil
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Improving Strength of Glulam Laminations of Norway Spruce Side Boards by Removal of Weak Sections Using Optimized Finger Jointing2014In: Materials and Joints in Timber Structures: Recent Developments of Technology / [ed] Simon Aicher; H.-W. Reinhardt ;Harald Garrecht, Springer, 2014, p. 801-811Conference paper (Refereed)
    Abstract [en]

    Recent research has shown that glulam laminations of Norway spruce side boards possess excellent structural properties. This investigation concerns the possibility of improving the performance of such laminations through elimination of weak board sections by means of finger jointing. Sections to be removed were identified using profiles of edgewise bending stiffness determined on the basis of scanned fibre angle fields on board surfaces. The difference in average tension strength and average tension stiffness, respectively, between a group of finger jointed boards and a reference group of non-jointed boards was evaluated. Joints were inserted in the first group with an average distance of 2.4 m. It was found that the finger jointing gave a considerable increase of strength (36 %), whereas the stiffness improvement was not as evident. Based upon the results, it can be assumed that application of finger jointed side board laminations will result in glulam beams with very high strength.

  • 319.
    Oscarsson, Jan
    et al.
    SP Technical Research Institute of Sweden, Sweden.
    Olsson, Anders
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Enquist, Bertil
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Localized modulus of elasticity in timber and its significance for the accuracy of machine strength grading2014In: Wood and Fiber Science, ISSN 0735-6161, Vol. 46, no 4, p. 489-501Article in journal (Refereed)
    Abstract [en]

    From previous research, it is well known that a localized modulus of elasticity (MOE) is a better indicating property (IP) of strength than an MOE averaged across a longer span. In this study, it was investigated to what extent the relationship, in terms of coefficient of determination (R2), between strength and localized MOE was dependent on the length across which the MOE was determined. Localized MOE was calculated with MOE profiles based on dot laser scanning of fiber directions, axial dynamic excitation, and a scheme of integration across a board's cross-section. Two board samples were investigated. Maximum R2 values, which were as high as 0.68 and 0.77, respectively, were obtained for localized MOE determined across lengths corresponding to about half the depth of the investigated boards. Consequently, application of a highly localized bending MOE as an IP will result in very competitive grading.

  • 320.
    Oscarsson, Jan
    et al.
    SP Technical Research Institute of Sweden, Sweden.
    Serrano, Erik
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Olsson, Anders
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Enquist, Bertil
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Identification of weak sections in glulam beams using calculated stiffness profiles based on lamination surface scanning2014In: Proceedings of the 2014 World Conference on Timber Engineering, Quebec, Canada, 10-14 August, Université Laval , 2014Conference paper (Refereed)
    Abstract [en]

    Models for estimation of structural properties of glued laminated timber (glulam) are generally based on the relationship between properties of the individual laminations and the properties of the glulam. In this investigation, a recently presented machine strength grading method based on laser scanning of fibre direction fields was applied for determination of axial modulus of elasticity (MOE) profiles along glulam laminations. These profiles were then used to calculate edgewise bending MOE (EB) profiles of glulam beams. The objectives were to investigate the relationship between position of bending failure and position of lowest EB value along investigated beams, and the relationship between the mentioned EB value and bending strength of the beams. It was found that both relationships were rather weak, whereas local bending MOE determined in accordance with EN408 was predicted with high accuracy on the basis of EB profiles.

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  • 321.
    Oskarsson, Malin
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Runeson, Siri
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    "Förlorad karaktär?": Inventering av 1970-talets villakvarter på Teleborg i Växjö2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    För att inte gå miste om den moderna bebyggelsen har det blivit mer aktuellt för alla kommuner i Sverige att studera och dokumentera den befintliga bebyggelsen. Ett området eller en byggnad som är uppförd under 1960- och 1970-tal berättar genom arkitekturen och områdets karaktär om den tids samhällsutveckling och historia. Detta gör att byggnader kan besitta olika kulturvärden och arkitektoniska kvalitéer som gör de är värda att bevara. Därför är det viktigt att förmedla kunskap till bostadsägare om bevarandeskäl så att nutida och kommande generationer inte ska gå miste om bebyggelsen, utan även få ta del av vår tids villaarkitektur.   

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  • 322.
    Pearson, Hamish
    et al.
    New Zealand Forest Research Institute (Scion), New Zealand.
    Ormarsson, Sigurdur
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Gabbitas, Brian
    University of Waikato, New Zealand.
    Nonlinear tensile creep behavior of radiata pineat elevated temperatures and different moisturecontents2015In: Holzforschung, ISSN 0018-3830, E-ISSN 1437-434X, Vol. 69, no 7, p. 915-923Article in journal (Refereed)
    Abstract [en]

    Tensile wood creep has not been measured previouslyin the temperature region 135°C – 150°C for a rangeof moisture content (MC) up to fiber saturation point dueto equipment and measurement challenges. Yet this is theregion where the most dramatic softening effects can beobserved. The aim of this study was to develop specializedequipment to measure tensile solid wood creep over70°C – 150° C for a range of MC and loads. Creep displacementwas successfully able to be isolated from elasticand mechanosorptive strains and statistically modeledby regression analysis. This proved more accurate thancomplex series expansions consisting of spring- and dashpot-type components. The best creep displacement relationshipwas a power law with a strain root mean squareerror of 0.28%. The amplitude of the power law was nonlinearwith respect to stress and temperature and changedby a stress factor of up to 0.9 for a stress of up to 1.2 MPaand by a temperature factor 1.2 – 6.3 over the investigatedrange. The creep relationship provides a valuable tool forpredicting time-dependent distortion and internal stressof wood during drying or thermohygromechanical modificationbelow 150°C.

  • 323.
    Persson, Karoline
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Suljeva, Arbnesha
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Utformning och dimensionering av ett flyttbart miljöhus i Växjö stad2015Independent thesis Basic level (university diploma), 180 HE creditsStudent thesis
    Abstract [sv]

    Befolkningstillväxten medför att fler och större skolverksamheter blir aktuellt i Sverige. Byggnationer medför att den befintliga källsorteringen kan förhindras vilket skapar ett behov av ett tillfälligt miljöhus under byggnationen.

    Rapporten presenterar ritningar, beräkningar samt en enkätundersökning om miljöhus i Växjö stad. Innehållet byggs på teori kring bygglov, sopsorteringens historia, renhållningens råd och rekommendationer, egenskaper hos material samt beräkningsmetoder.

    För miljöhusets konstruktionselement används trä som takstolsmaterial och stål för resterande bärande element. Miljöhuset ska med enkla hjälpmedel kunna förflyttas inom Växjö stad. Utformningen och de förutsättningar som krävs för ett tillfälligt bygglov för miljöhuset presenteras.

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  • 324.
    Persson, Tobias
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Hannu, Oscar
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Träfasader på höga hus: Brandtekniska möjligheter2019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The Swedish legislation of building code was changed in 1994, allowingconstruction of wooden buildings over two floors. To do so there are certainfunctional requirements that must be fulfilled to obtain fire safety. This studydetermines the level of knowledge of different contractors in the constructionindustry in the subject through interviews. The possibilities of using wooden facadesin high-rise building are also presented. The study shows that several possibilities touse wooden facades i high rise buildings are possible according to the legislation.Contractors in the industry consider their knowledge to be sufficient but believesthere is a general lack of knowledge in the industry regarding fire safetyrequirements.

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  • 325.
    Persson, Victoria
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Andersson Hjelm, Nora
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Hur kan arkitekturen påverkas av miljöcertifieringssystemet Miljöbyggnad?2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Klimatförändringarna på jorden är idag ett faktum. En metod som uppmanar att bygga miljövänligt är miljöcertifieringssystem. I början av 1990-talet började miljöcertifieringssystem att etableras och intresset för miljöcertifieringssystem blev då väldigt stort. Miljöcertifieringssystemet Miljöbyggnad utgår från svenska regler och svensk byggpraxis.

    I detta examensarbete skall det undersökas hur arkitekturen påverkas av miljöcertifieringssystemet Miljöbyggnad. Därför har även studien om arkitektonisk kvalitet beaktas.

    Detta examensarbete utgår från ett referensobjekt, en sjukhusbyggnad, som skall uppnå nivå GULD inom Miljöbyggnad. Region Örebro län anordnade en arkitekttävling för den nya vårdbyggnaden, H-huset, som skall byggas intill det nuvarande universitetssjukhuset i Örebro. Det var Sweco arkitekter i Örebro som tillsammans med danska AART Architets vann tävlingen. 

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  • 326.
    Petersson, Hans
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Källsner, Bo
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Ormarsson, Sigurdur
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Strength grading of structural timber based on buckling analysis and scanning techniques2016In: Proceedings of the 2016 World Conference on Timber Engineering (WCTE) / [ed] J. Eberhardsteiner, W. Winter, A. Fadai, M. Pöll, Vienna: Vienna University of Technology , 2016Conference paper (Refereed)
    Abstract [en]

    This paper assesses the potential of grading of structural timber by use of in-plane buckling analysis combined with scanning, employing post processing of both ordinary photo images and images of wood surfaces illuminated by a large number of laser point sources. The results appear very promising in providing accurate predictions of structural strength. Finite element modelling is applied in the buckling analysis and obtained results are compared with experimental results from timber boards tested in accordance to the European standard EN 408 by four point bending tests.

  • 327.
    Petersson, Hans
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Ormarsson, Sigurdur
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Källsner, Bo
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Vessby, Johan
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Influence of structural stability and material property variations on bending strength of solid timber2015In: Theoretical, Numerical, and Experimental Analyses in Wood Mechanics, 2015Conference paper (Refereed)
  • 328.
    Petersson, Lovisa
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Tarabeih, Qamar
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Utformning av flerbostadshus med avseende på trygghet och trivsel2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The housing shortage from which occurred in Sweden after the second world war was solved through a housing project that later became known as The Million Homes Programme (miljonprogrammet). The houses were built with high standards according to the contemporary indoor standards, while the outside environment was often somewhat dull and non-prioritized. At this moment, Sweden is facing a similar type of housing shortage, a problem that should not be solved with the same methods used during The Million Homes Programme.

    The main purpose of this thesis is to develop a suggestion of a building design and a site layout plan in a small town, in collaboration with a Swedish municipality in Kronoberg county. The goal is to explore the different possibilities of how an estate owned by the municipality of Uppvidinge could be designed with multi-family houses which pays respect to safety and comfort and also is adapted to the surrounding built environment. The surrounding built environment consists of multi-family houses from The Million Homes Programme and one-family villas.

    The methods used for this thesis are pointed interviews, studies of prior published research and computer aided drawing. A suggestion of a building design accompanied with a site layout plan is presented in the report. The building design and the site layout plan pays respect to safety besides comfort and is also adapted to the surrounding built environment.

    The completed studies resulted in opinions about what should be a priority when designing multi-family houses on the site, but also what kind of qualities that were desired in the surrounding area. These results were analyzed and thence linked to the theoretical background. The analyzed result was thereafter applied in a suggestion.

    The study resulted in a suggestion that was well received by the client, which hopefully will be inspired for further work on site.

     

    Key words: design plans, modern planning arrangement, site plan, apartment building, new housing estate, the million homes programme, safety, comfort, visualization, building design, housing adaptation, safe environment, residences, building permit documents, outdoor environment. 

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    180628-UtformningAvFlerbostadshusMedAvseendePaTrygghetOchTrivsel
  • 329.
    Petersson, Robin
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Gajos, Kristian
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Bestämning av statiska friktionskoefficienter mellan trä och stål2019Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Med teknikens framfart finns ett ökat behov av numeriska simuleringar avträförband. För att erhålla ett mer tillförlitligt resultat finns ett behov av noggrannarefriktionskoefficienter vid olika förhållanden som påverkar lastöverföring.I den här studien undersöks friktionen mellan materialen LVL (laminated veneerlumber; fanerträ) och stål. Målet är att studien ska resultera i friktionskoefficienterför olika varierande förhållanden som sedan kan användas vid t.ex. olika numeriskasimuleringar.Friktionstesterna utfördes genom att succesivt öka vinkeln på glidytan i form av enstålplatta där en provkropp var placerad. Vinkeln ökades tills det att provkroppenhamnade i rörelse, den uppnådda vinkeln registrerades och räknades sedan om till enfriktionskoefficient.Totalt utfördes 1 800 friktionstester för att ge god statistisk grund åt de slutgiltigamedelvärdena för friktionskoefficienterna. Undersökningen resulterade i enfriktionskoefficient i form av ett medelvärde för respektive varierande förhållande.

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  • 330.
    Petersson, Viktor
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Gustafsson, Johan
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Beräkningsmetoder för verifiering av svetsar med inriktning på PWT2019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Steel is a material used in various building structures. Fatigue can occur in the material if building structures is exposed for repeated loads. Fatigue leads to permanent damages such as crack initiations and fracture. It is common that welds in welded structures have the lowest fatigue strength. A welds fatigue strength can be improved with treatments termed Post Weld Treatment (PWT).

    Today a welds fatigue strength is verified with a method described in Eurocode. The calculation method is simplified which can underestimate the objects number of lifecycles regarding fatigue. The purpose with this essay is to study different structural design methods for fatigue exposed welds and how many lifecycles a typeweld will increase when applying PWT. The goal with this essay is to study a typeweld and calculate the number of lifecycles between the calculation methods and to show how many lifecycles the same type weld will increase when applying PWT.

    The results and theory are based on scientific articles, literature studies and a casestudy which both contains a through welded butt weld and a fillet weld placed on an I-beam. The results points at that the calculation method that is used today underestimates the number of lifecycles and that the number of lifecycles increased significant after PWT.

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  • 331.
    Pettersson, Jenny
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Wiberg, Sara
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Tidseffektivisering av materialleveranser på byggprojekt med radiofrekvensidentifikation, RFID2015Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Studien undersöker möjligheten för tidseffektivisering av materialleveranser med hjälp av RFID, radiofrekvensidentifikation. RFID är en trådlös teknik som används för att identifiera föremål.

    För att ta reda på vilka problem som uppkommer på dagens byggarbetsplatser genomfördes intervjuer på fyra olika projekt där Skanska Sverige AB är entreprenör. Genom sammanställning av intervjuerna gjordes en kartläggning av materialflöden och materialhantering på samtliga projekt. Dessa problem diskuterades därefter med en sakkunnig inom RFID och resultatet visar förslag på hur RFID kan användas för att uppnå en effektivare materialhantering.

    Huvudförslaget som analysen redovisar är tidseffektivisering av mottagandekontroller vid materialleveranser. Genom att använda RFID finns möjlighet att automatisera mottagningskontroller. Företaget kan redan vid avlastning upptäcka om material saknas och på så sätt tidseffektivisera byggprojekt. Dock är denna lösning svår att genomföra då mycket behöver förändras i materialflödesprocessen innan RFID införskaffas.

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  • 332.
    Phiri, Darius
    et al.
    Univ Stellenbosch, South Africa.
    Ackerman, Pierre
    Univ Stellenbosch, South Africa.
    Wessels, Brand
    Univ Stellenbosch, South Africa.
    du Toit, Ben
    Univ Stellenbosch, South Africa.
    Johansson, Marie
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Säll, Harald
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Lundqvist, Sven-Olof
    Innventia AB, Wood & Fibre Measurement Lab, Stockholm.
    Seifert, Thomas
    Univ Stellenbosch, South Africa.
    Biomass equations for selected drought-tolerant eucalypts in South Africa2015In: Southern Forests, a journal of forest science, ISSN 2070-2620, E-ISSN 2070-2639, Vol. 77, no 4, p. 255-262Article in journal (Refereed)
    Abstract [en]

    In the water-scarce environment of South Africa, drought-tolerant eucalypt species have the potential to contribute to the timber and biomass resource. Biomass functions are a necessary prerequisite to predict yield and carbon sequestration. In this study preliminary biomass models for Eucalyptus cladocalyx, E. gomphocephala and E. grandis x E. camaldulensis from the dry West Coast of South Africa were developed. The study was based on 33 trees, which were destructively sampled for biomass components (branchwood, stems, bark and foliage). Simultaneous regression equations based on seemingly unrelated regression were fitted to estimate biomass while ensuring additivity. Models were of the classical allometric form, ln(Y) = a+x(1)ln(dbh)+x(2)ln(h), of which the best models explained between 70% and 98% of the variation of the predicted biomass quantities. A general model for the pooled data of all species showed a good fit as well as robust model behaviour. The average biomass proportions of the stemwood, bark, branches and foliage were 60%, 6%, 29% and 5%, respectively.

  • 333.
    Piccardo, Chiara
    et al.
    University of Genoa, Italy.
    Dodoo, Ambrose
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Gustavsson, Leif
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Tettey, Uniben Yao Ayikoe
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Retrofitting with different building materials: life-cycle primary energy implications2020In: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 192, p. 1-13, article id 116648Article in journal (Refereed)
    Abstract [en]

    The energy retrofitting of existing buildings reduces the energy use in the operation phase but the use ofadditional materials influence the energy use in other life cycle phases of retrofitted buildings. In thisstudy, we analyse the life cycle primary energy implications of different material alternatives whenretrofitting an existing building to meet high energy performance levels. We design retrofitting optionsassuming the highest and lowest value offinal energy use, respectively, for passive house standardsapplicable in Sweden. The retrofitting options include the thermal improvement of the building enve-lope. We calculate the primary energy use in the operation phase (operation primary energy), as well asin production, maintenance and end-of-life phases (non-operation primary energy). Our results showthat the non-operation primary energy use can vary significantly depending on the choice of materialsfor thermal insulation, cladding systems and windows. Although the operation energy use decreases by63e78%, wefind that the non-operation energy for building retrofitting accounts for up to 21% of theoperation energy saving, depending on the passive house performance level and the material alternative.A careful selection of building materials can reduce the non-operation primary energy by up to 40%,especially when using wood-based materials

  • 334.
    Plesec, Alexander
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Hodzic, Enis
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Tillbyggnad av kontors- och laboratorielokaler vid hus M, Linnéuniversitetet, Växjö2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Detta arbete ger ett förslag på en tillbyggnad av hus M på Linnéuniversitetet i Växjö.

    Kvalitativa intervjuer med kvantitativa inslag har utförts för att ta reda på lokalbehovet. Vid gestaltning av ett förslag finns det lagar, föreskrifter och rekommendationer som ska tas hänsyn till för att kunna skapa en ändamålsenlig och funktionell byggnad. Det finns även en mängd olika arkitektoniska kvalitéter att tänka på som t.ex. flexibilitet och rörelse.

    Förslaget till en tillbyggnad är en sammanvägning av de tillfrågades åsikter, teorin och utformarnas egna kunskaper. Förslaget presenteras med förklaringar, ritningar och visualiseringsbilder som beskriver gestaltningen och utformningen av den föreslagna tillbyggnaden.

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  • 335.
    Porselius, Matilda
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Svensson, Mattias
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Hemma i Husby: En studie om hur utformning av den fysiska miljön kan öka tryggheten i Husby2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This study is conducted on behalf of ÅWL Arkitekter and is about how the configuration and design of the physical environment can influence the perceptions of security. The study is about a square in the suburb Husby, in northern part of Stockholm. Husby is characterized by insecurity. The district was built during the so called “million apartment program”.

    The purpose with the study is to examine which factors in the physical environment has an influence on people’s experience and perceptions. The goal is to present a design for the square in order to make it to a meeting place, which can contribute to inhabitants’ feelings of security and safety. The study is based on interviews and observations.

    The actions within the physical environment that has the greatest influence on people’s perceptions of security, seems to be lightning, meeting places, common activities and vegetation. The design and proposals is based on these conceptions.

    Security is a complex matter and it contains various aspects. It takes a lot of actions in several areas to solve issues regarding security. The design of the physical environment can be a contributory factor among others.

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    Hemma i Husby Porselius & Svensson
  • 336.
    Rada, Darun
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Roil Beto, Eitota
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Isolerat parallelltak ur fuktperspektiv2016Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    I denna studie undersöks fuktomlagring och mögelpåväxten i en ventilerad och en ickeventilerad parallelltakkonstruktion med hjälp av mätningar och simuleringar. För att kunna se om risk av mikrobiell påväxt föreligger under en specifik tidsperiod, används mögeldosmodellen och Wufi Bio.

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  • 337.
    Rahmani, Ehsan
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Valencia, Gabriel
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Är bullerreduktionen intill trafikerade vägar tillfredställande för boende i hus med träkonstruktion?2020Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Bullerreduktionen i väggar med lastbärande trästomme har undersökts för att se om denna typ av konstruktion kan placeras intill högt trafikerade vägar. I studien visas att det går att bygga träväggar i byggnader nära vägar med hög trafikbelastning. Mätobjektet var en träbyggnad som är placerad 30 meter från mitten av vägen där ljudkällan befinner sig. Mätningar genomfördes i tre olika tidsperioder och för två olika placeringar av mätutrustningen invändigt och strax utanför en lägenhet, där instrumentet riktades mot ljudkällan för att få ett tillförlitligt resultat. Resultatet av mätningarna användes som utgångspunkt för att ge ett förslag på hur ljudisoleringen i en vägg ytterligare kan förbättras.

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    Examenarbete
  • 338.
    Rask, Linus
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Anpassning av befintlig byggnad till nutida krav och behov för trygghetsboende2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Detta examensarbete utreder nutidakrav, bestämmelser och kvalitéer vid utformning av ett så kallat Trygghetsboende enligt svensk standard.

    Resultatet av rapporten redovisas i form av ett gestaltningsförslag av en befintligbyggnad utifrån de teorier, litteratur och de studier jag har tagit del av i denna rapporten.

    Rapporten syftar i att man skall kunna utforma ett trygghetsboende utifrån de bestämmelser som sammanställts i denna rapport och samtidigt beakta de bostads kvalitéer för de äldre generationerna.

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  • 339.
    Renström, Pontus
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Gustavsson, Andreas
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Jämförelse av dimsprinkler, boende- och traditionella sprinklersystem2020Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    High rise buildings lead to higher demands on the fire safety. Installation of a sprinkler system can help to achieve these requirements.The purpose of this study is to compare a system with traditional sprinkler, residential sprinkler and high-pressure water mist sprinkler in a case study. The goal is to show what different qualities the systems possess and which physical impact they bring to the building.This study shows that the high-pressure water mist performs on a higher level compared to the other sprinkler systems, even though it, today, is the least utilized system for buildings.

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  • 340.
    Reynolds, Thomas
    et al.
    University of Bath, UK.
    Bolmsvik, Åsa
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Vessby, Johan
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Chang, Wen-Shao
    University of Bath, UK.
    Harris, Richard
    University of Bath, UK.
    Bawcombe, Jonathan
    Cambridge Unviersity, UK.
    Bregulla, Julia
    Building Research Establishment (BRE), UK.
    Ambient vibration testing and modal analysis of multi-storey cross-laminated timber buildings2014In: World conference on timber engineering (WCTE), 2014Conference paper (Refereed)
    Abstract [en]

    The ambient movement of three multi-storey cross-laminated timber (CLT) buildings have been measured and used to determine natural frequencies, mode shapes and damping ratios. This information, obtained by a simple, unobtrusive series of tests, can give insights into the structural performance of this form of building, as well as providing information for the design of future, taller timber buildings for dynamic loads. For two of the buildings, the natural frequency has been related to the lateral stiffness of the structure, and compared with the stiffness based on simple calculation. In future tall timber buildings, a new design criterion is expected to become important: deflection and vibration serviceability under wind load. Design standards give techniques for prediction and mitigation of wind-induced movement, but require an estimate of the mass, stiffness and damping ratio of the structure to make an accurate prediction. For multi-storey timber buildings there is no empirical basis to use for damping estimation, and there is little information for stiffness. This study therefore provides an insight into the modal properties for lateral vibration of multi-storey CLT construction which could inform the design of taller buildings in the future.

  • 341.
    Rikner, Viktor
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    von Platen, Hampus
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Mätningar och simuleringar av fukt i tak2015Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    På grund av att det hela tiden kommer nya sätt att bygga på uppstår nya problem varav många är fuktrelaterade. I rapporten undersöks en specifik parallelltakskonstruktion med hjälp av loggning. Mätningarna jämförs sedan med simuleringar i programmet Wufi® Pro 5.3 för att se om det föreligger risk för att fuktproblem skulle uppstå inne i konstruktionen.

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  • 342.
    Rosbladh, Emma
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Einarsson, Maria
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Utformning av ett campinghotell2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Med förhoppning av att öka spontanturismen till kommunen samt campingens,Tingsryd Resort, dragkraft har ett förslag på ett campinghotell tagits fram.

    Extra viktigt för ett hotell är själva placeringen, det ska sticka ut och locka förbipasserande till platsen, vilket gynnas om det placeras i närhet av en större trafikled. På en camping är närheten till natur och vatten även en viktig parameter som kan locka de besökare som vill bo lugnt men ändå ha nära till diverse aktiviteter.

    Det finns 2 förslag att välja mellan, vilka redovisas genom detaljerade ritningar och illustrationer. Dessa skiljer sig i form och har utformats i olika kulörer för att ge inspiration till hur det kan se ut.

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  • 343.
    Rubenson, Sarah
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Utformning av ett flerbostadshus enligt detaljplan2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Arbetet grundar sig på en fastighetsägares insikt om att nuvarande bebyggelse inte följer detaljplan och hennes nyfikenhet kring hur tomten skulle kunna disponeras och ett flerbostadshus utformas på så sätt att detaljplan följs. På vägen passeras huvudpunkterna utformning enligt detaljplan, godkända energikrav enligt Boverket och skapandet av en solstudie. 

    Tomten som behandlas är en del av en kvartersbebyggelse i centrala Ängelholm. Staden som närmar sig femhundra år bär på en lång historia och byggnaderna inom kvarteret är klassade som värdefull bebyggelse eller särskilt värdefull bebyggelse enligt plan- och bygglagen (8 kap. § 13). Detaljplanen har i sin tur stämplat hela området som lagskyddade kulturlager vilket kräver ytterligare försiktighetsåtgärder. Stadens historia har tillsammans med dessa bemärkelser kraftigt kommit att påverka utformningen av ett nytt flerbostadshus.

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  • 344.
    Rydberg, Erik
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Johannesson, Andreas
    Laserskanning av Södra Climate Arena2016Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Rapporten går ut på att se om laserskanning är en bra metod att använda sig av vid ombyggnation, tillbyggnad och renovering. För att få fram ett svar på detta har två takbalkar i Södra Climate Arena skannats av. Vid genomförandet användes en laserskanner från Leica av varianten P30. Försöket innehåller fyra stycken uppställningar som riktas mot sex stycken måltavlor. Informationen som fåtts ut från skanningen i form av en sektion i AutoCAD har jämförts med befintliga ritningar för att se om informationen från skanningen stämmer överens med ritningarna. I modellen som fåtts ut från försöket har också mätning och undersökning skett för att se hur bra det går att mäta i modellen och om det är något som fungerar lätt att använda sig av i praktiken. Arbetet går även ut på att få en god inblick i hur laserskannern Leica P30 fungerar.

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    Exjobb
  • 345.
    Rydholm, Marcus
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Lowenfalk, Rasmus
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Banviksbrottet - Parkeringshus i kombination med radhus: En hållbar lösning till parkeringsbrist?2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report contains a design proposal of how to solve the lack of parking spaces inthe district Gamlestan in Lysekil kommun with a multistory car park in combinationwith terraced houses on top. The proposal is presented through illustrations,describing text and blueprints. Choice of building materials, possible constructionsolution, PBL, BBR, fire safety, stormwater management and economy is taken inconsideration.

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    Banviksbrottet - Parkeringshus i kombination med radhus
  • 346.
    Saad, Ahmad
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Material properties of concrete used in skewed concrete bridges2016Independent thesis Advanced level (degree of Master (One Year)), 40 credits / 60 HE creditsStudent thesis
    Abstract [en]

    This thesis has discussed both properties and geometry of concrete slabs used in bridges.

    It gave understanding on behavior of concrete in both tension and compression zones and how crack propagates in specimens by presenting both theory of fracture and performing concrete tests like tension splitting, uniaxial compression and uniaxial tension tests.

    Furthermore, it supported experimental tests with finite elements modelling for each test, and illustrated both boundary conditions and loads.

    The thesis has used ARAMIS cameras to observe crack propagations in all experimental tests, and its first study at LNU that emphasized on Brazilian test, because of importance of this test to describe both crushing and cracking behavior of concrete under loading.

    It’s an excellent opportunity to understand how concrete and steel behave individually and in combination with each other, and to understand fracture process zone, and this has been discussed in theory chapter.

    The geometry change that could affect stresses distributions has also described in literature and modelled to give good idea on how to model slabs in different angles in the methodology chapter.

    Thus, thesis will use finite elements program (Abaqus) to model both experimental specimens and concrete slabs without reinforcement to emphasize on concrete behavior and skewness effect. This means studying both properties of concrete and geometry of concrete slabs. This thesis has expanded experimental tests and chose bridges as an application.

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    fulltext
  • 347.
    Schill, Elin
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Flodins, Tina
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Effekter vid tilläggsisolering av kallvindar ur fuktsynpunkt2015Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Ekonomiska aspekter och krav på minskad energianvändning leder bland annat till tilläggsisolering av vindsbjälklag och byte av uppvärmningssystem. Åtgärderna ger ett kallare och fuktigare klimat på vinden vilket gynnar mögeltillväxt. Minst 60 % av alla traditionella vindar med självdrag kan anses ha riklig tillväxt av mögelsvamp (Ahrenens och Borglund 2007). Syftet med denna studie är att ta ett steg i rätt riktning om vilka åtgärder som kan göras på de vindar som idag är angripna.

    I denna studie har tre vindars fukttillstånd utretts och jämförts. Ett av objekten har simulerats och utsatts för olika åtgärder. Simuleringarna bekräftar att minskad isolering ger ett torrare klimat på vinden. En ökning av ventilationen ger liten men knappt märkbar förbättring av vindsklimatet. Hög värmekapacitivitet hos isoleringsmaterial verkar ge en jämnare temperatur på vinden vilket sänker luftfuktigheten. Genom att isolera vindens tak och gavlar sker en markant sänkning av mögelrisken. Då varje vind är olika uppbyggd finns ingen generell lösning utan varje vind måste bedömas utifrån sina nuvarande förhållanden.

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    Effekter vid tilläggsisolering av kallvindar ur fuktsynpunkt
  • 348.
    Schirén, Whokko
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Swahn, Trixie
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Vibrations in residential timber floors: A comparison between the current and the revised Eurocode 52019Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The European standard Eurocode 5, a design method for timber structures,is currently under revision. In this study the draft for a reviseddesign method for vibrations in timber floors was compared to the currentmethod. The hypothesis of the thesis was that the revised designmethod might force some changes to the present construction practiceand that these changes may carry with them increased costs for the industry.Six common floor structures used in Sweden today were identifiedand for these floors design calculations were made according to the currentand the revised design method. It was checked whether the floorspassed the criteria in the two design methods and a comparison was madefor the only criterion which could be compared between the methods, thepoint load deflection. Floor structures could pass or fail the current designmethod based on two criteria, the point load deflection and the unitimpulse velocity response. All floors passed the current design methodexcept one which had a fundamental frequency below 8 Hz, because ofthe low frequency the current design method was not applicable to thefloor structure. In the revised design method the final result is a responsefactor and based on the response factor floors are given floor performancelevels. The seven step scale for the floor performance level go from I toVII where I is excellent and VII is unacceptable. All floor structures excepttwo achieved an acceptable floor performance level according to therevised design method. The two floors which failed were floors commonlyused in single family houses, they failed for a span length commonly usedtoday. A limited parametric study was performed where it was found thatthe modal mass used had a larger impact on the floor performance levelthan the mass per square meter included. For floors with a fundamentalfrequency above 8 Hz, including a higher mass per square meter resultedin a lower, i.e. better, response factor in all cases except one. For floorswith a fundamental frequency between 4.5 and 8 Hz, a higher mass resultedin a higher, i.e. worse, response factor. The study found that notall floor structures used in Sweden today are acceptable according to therevised design method therefore changes may have to be implemented andthese changes could result in an increased cost.

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    fulltext
  • 349.
    Schmid, Joachim
    et al.
    ETH Zürich, Switzerland.
    Klippel, Michael
    ETH Zürich, Switzerland.
    Östman, Birgit
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Fire performance of bio-based building materials2017In: Performance of bio-based building materials / [ed] Dennis Jones and Christian Brischke, Woodhead Publishing Limited, 2017, p. 305-320Chapter in book (Refereed)
    Abstract [en]

    This chapter gives an introduction into the background and the usage of these two characteristics and highlights important points for bio-based building products. Further, the authors give guidance for research topics, relevant boundary conditions, limitations, related standards and further literature.

  • 350.
    Schweigler, Michael
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Bocquet, Jean-Francois
    University of Lorraine, France.
    Lemaitre, Romain
    University of Lorraine, France.
    Sandhaas, Carmen
    Karlsruhe Institute of Technology, Germany.
    Database of embedment parameters from soft- and hardwoods2019Data set
    Download full text (zip)
    Embedment parameter database
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