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Numerical Analysis of Point-Fixed Glass BalustradesLago, Simon, Höier, Johan January 2019 (has links)
The design approach is currently very diverse for glass. It differs greatly between European countries and there is not one definite method for the design of glass components. Research in this field has a potential for better design optimization and industry professionals express a limitation of tools and knowledge about glass structure design.The purpose of this study is to analyze glass balustrades with point-fixings and to test a structural verification approach using a Finite Element (FE) software. The theory provides insight of glass as a structural material, different interlayers used for laminated glass, joints and connections, as well as design standards, concepts and regulations. Different models of varying configurations and geometries are created from the evaluation of balustrades with point-fixings available on the Swedish market and the theory. The models represent a glass balustrade with 4- or 6-point-fixings and is regarded as a fully toughened laminated glass component with different stiff and standard interlayers. The structural analysis of point-fixed glass balustrades on the Swedish market indicated a lower stress and deflection resistance capacity than the pre-normative Eurocode criterion. Based on the FE calculations, some guidelines for fulfilling the criterion are proposed.To make glass more generally applicable as a load-bearing material, the limitations of the FE-software, and how the parameters affect the calculation results needs to be taken into consideration. In order to evaluate the interlayers used for the model, a parametric study using FE-analysiswas carried out, in which the maximum stresses and deflections for several variations were calculated. A sensitivity analysis of the balustrade was conducted to evaluate various geometric and material parameters and how they affect the FE software-based model. Comparisons of guidelines and national codes for simplified hand-calculation and the FE-approach were made to obtain some understanding of calculation methods used in the glass industry and to evaluate the results of the structural analysis. The study suggests that the FE approach is an effective method for a relatively quick and easy verification of glass balustrades.
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Tilläggsisolering inom byggnadsvårdHultberg, Ann-Charlotte, Larsson, Emelie January 2009 (has links)
<p>Främsta anledningen till en tilläggsisolering är att det önskas bättre energihushållning i en byggnad. Detta kan göras med olika material och olika tekniker. Inom byggnadsvårdssammanhang förs det en diskussion om de fuktbuffrande materialen är bättre vid tilläggsisolering då de är hygroskopiska än de icke hygroskopiska som är mest frekvent använda i det konventionella byggandet. Denna rapport utvärderar om det finns några dokumenterade fakta som styrker att de hygroskopiska och ekologiska materialen fungerar bättre i byggnadsvårdssammanhang än de icke hygroskopiska. Olika isolermaterial från de två nämnda grupperna jämförs utifrån olika parametrar.</p> / <p>This report evaluates if there are any known facts that support that the hygroscopic and ecologic materials are better in supplement insulation than non hygroscopic. Different kind of insulate materials from these two mentioned groups are compared from without different kind of parameters.</p>
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Konstruktionslek på förskolan / Construction-play at the preschoolGustavsson, Anita January 2008 (has links)
<p>Genom kvalitativa intervjuer med fem förskollärare och observationer av konstruktionsmaterial på förskolan har jag fått svar på mina frågeställningar. Mina frågeställningar handlar om vilka material förskolan har till tredimensionell konstruktionslek inomhus och om det arbetas medvetet med tredimensionell konstruktionslek. Syftet med studien är att undersöka förutsättningarna för tredimensionell konstruktionslek på förskolan.</p><p>Rapporten visar att tillgången till konstruktionsmaterial på förskolorna inte är särskilt varierad och inte tillräckligt stor. Enligt svaren på intervjuerna är den största orsaken bristen på tid för pedagogerna att vara delaktig i konstruktionsleken. Det saknades även tid att hålla ordning på konstruktionsmaterialet. Pedagogerna arbetar inte medvetet med konstruktionslek och upplever att de saknar tillräckliga kunskaper inom ämnet.</p><p>Utifrån gällande styrdokument är leken viktig för barns lärande. Barnen skall utveckla sin förmåga att bygga, skapa och konstruera med hjälp av olika material. Denna studie visar att för att uppfylla dessa krav bör lärare i förskolan få mera kunskaper om konstruktionslekens betydelse och hur man kan arbeta med den.</p> / <p>My purpose with this study is to investigate the preschools conditions of the three-dimensional construction play.</p><p>My questions are: what indoor material the preschool posses and the awareness of working with three-dimensional construction play.</p><p>The answers I got are based on the qualitative interviews with five preschoolteachers and also from doing observations of the preschools construction materials.</p><p>The report shows that the access to the construction materials are not that varied and not big enough. According to the answers from the interviews, is the main reason the preschoolteachers lack of time to participate in the construction play. They are also lacking time to maintain the order of the construction materials. The preschoolteachers don’t work consciously with the construction play and they feel that they don’t have adequate knowledge in this subject.</p><p>On the basis of current control documents are the children’s play important for their learning. The children shall develop the ability to build, create and construct with help from different materials. This study shows that to fulfil these demands, the preschoolteachers should get more knowledge about the meaning of the construction play and how to work with it.</p>
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Konstruktionslek på förskolan / Construction-play at the preschoolGustavsson, Anita January 2008 (has links)
Genom kvalitativa intervjuer med fem förskollärare och observationer av konstruktionsmaterial på förskolan har jag fått svar på mina frågeställningar. Mina frågeställningar handlar om vilka material förskolan har till tredimensionell konstruktionslek inomhus och om det arbetas medvetet med tredimensionell konstruktionslek. Syftet med studien är att undersöka förutsättningarna för tredimensionell konstruktionslek på förskolan. Rapporten visar att tillgången till konstruktionsmaterial på förskolorna inte är särskilt varierad och inte tillräckligt stor. Enligt svaren på intervjuerna är den största orsaken bristen på tid för pedagogerna att vara delaktig i konstruktionsleken. Det saknades även tid att hålla ordning på konstruktionsmaterialet. Pedagogerna arbetar inte medvetet med konstruktionslek och upplever att de saknar tillräckliga kunskaper inom ämnet. Utifrån gällande styrdokument är leken viktig för barns lärande. Barnen skall utveckla sin förmåga att bygga, skapa och konstruera med hjälp av olika material. Denna studie visar att för att uppfylla dessa krav bör lärare i förskolan få mera kunskaper om konstruktionslekens betydelse och hur man kan arbeta med den. / My purpose with this study is to investigate the preschools conditions of the three-dimensional construction play. My questions are: what indoor material the preschool posses and the awareness of working with three-dimensional construction play. The answers I got are based on the qualitative interviews with five preschoolteachers and also from doing observations of the preschools construction materials. The report shows that the access to the construction materials are not that varied and not big enough. According to the answers from the interviews, is the main reason the preschoolteachers lack of time to participate in the construction play. They are also lacking time to maintain the order of the construction materials. The preschoolteachers don’t work consciously with the construction play and they feel that they don’t have adequate knowledge in this subject. On the basis of current control documents are the children’s play important for their learning. The children shall develop the ability to build, create and construct with help from different materials. This study shows that to fulfil these demands, the preschoolteachers should get more knowledge about the meaning of the construction play and how to work with it.
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Tilläggsisolering inom byggnadsvårdHultberg, Ann-Charlotte, Larsson, Emelie January 2009 (has links)
Främsta anledningen till en tilläggsisolering är att det önskas bättre energihushållning i en byggnad. Detta kan göras med olika material och olika tekniker. Inom byggnadsvårdssammanhang förs det en diskussion om de fuktbuffrande materialen är bättre vid tilläggsisolering då de är hygroskopiska än de icke hygroskopiska som är mest frekvent använda i det konventionella byggandet. Denna rapport utvärderar om det finns några dokumenterade fakta som styrker att de hygroskopiska och ekologiska materialen fungerar bättre i byggnadsvårdssammanhang än de icke hygroskopiska. Olika isolermaterial från de två nämnda grupperna jämförs utifrån olika parametrar. / This report evaluates if there are any known facts that support that the hygroscopic and ecologic materials are better in supplement insulation than non hygroscopic. Different kind of insulate materials from these two mentioned groups are compared from without different kind of parameters.
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"Jag ska också göra chokladbollar" : En undersökning om hur tillgången till konstruktionsmaterial påverkar barn i förskolan / "I´ll also make chocolate balls" : A study on how the availability of construction materials affect children in preschoolWiklund, Ramona January 2014 (has links)
The aim of this study was to investigate and compare the availability of construction materials affect children's constructions and play. Observations were made when the children were allowed to play and build with very little and much of the material play-doh dough in preschool. The study is aimed at children aged 3 – 5 years. Interviews were also conducted with educators in departments where the children spent time to give support to this study. The result shows that the children create as many designs of any material amount. At smaller amount of the same material of construction results show that children vary more among different games. / Syftet med det här examensarbetet var att undersöka och jämföra hur tillgången till konstruktionsmaterial påverkar barns konstruktioner och lek i förskolan. Undersökningen riktar sig mot barn i åldrarna 3 – 5 år. Observationer gjordes när barnen fick leka och konstruera med tillgång till mycket och lite av materialet play- doh deg. Även intervjuer gjordes med pedagoger på avdelningarna där barnen vistades för att ge stöd i arbetet. Resultatet visar att barnen skapar lika många konstruktioner oavsett materialmängd. Vid mindre mängd av samma konstruktionsmaterial visar resultatet att barnen skiftar mer mellan olika lekar.
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A Study of Failure Development in Thick Thermal Barrier CoatingsCarlsson, Karin January 2007 (has links)
<p>Thermal barrier coatings (TBC) are used for reduction of component temperatures in gas turbines. The service temperature for turbines can be as high as 1100ºC and the components are exposed to thermal cycling and gases that will cause the component to oxidize and corrode. The coatings are designed to protect the substrate material from this, but eventually it will lead to failure of the TBC. It is important to have knowledge about when this failure is expected, since it is detrimental for the gas turbine.</p><p>The scope of this thesis has been to see if an existing life model for thin TBC also is valid for thick TBC. In order to do so, a thermal cycling fatigue test, a tensile test and finite element calculation have been performed. The thermal cycling fatigue test and finite element calculation were done to find correlations between the damage due to thermal cycling, the number of thermal cycles and the energy release rate. The tensile test was preformed to find the amount accumulated strain until damage.</p><p>The thermal cycling lead to failure of the TBC at the bond coat/top coat interface. The measurment of damage, porosity and thickness of thermally grown oxide were unsatisfying due to problems with the specimen preparation. However, a tendency for the damage development were seen. The finite element calculations gave values for the energy release rate the stress intensity factors in mode~I and mode~II that can be used in the life model. The tensile test showed that the failure mechanism is dependent of the coating thickness and it gave a rough value of the maximum strain acceptable.</p>
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A Study of Failure Development in Thick Thermal Barrier CoatingsCarlsson, Karin January 2007 (has links)
Thermal barrier coatings (TBC) are used for reduction of component temperatures in gas turbines. The service temperature for turbines can be as high as 1100ºC and the components are exposed to thermal cycling and gases that will cause the component to oxidize and corrode. The coatings are designed to protect the substrate material from this, but eventually it will lead to failure of the TBC. It is important to have knowledge about when this failure is expected, since it is detrimental for the gas turbine. The scope of this thesis has been to see if an existing life model for thin TBC also is valid for thick TBC. In order to do so, a thermal cycling fatigue test, a tensile test and finite element calculation have been performed. The thermal cycling fatigue test and finite element calculation were done to find correlations between the damage due to thermal cycling, the number of thermal cycles and the energy release rate. The tensile test was preformed to find the amount accumulated strain until damage. The thermal cycling lead to failure of the TBC at the bond coat/top coat interface. The measurment of damage, porosity and thickness of thermally grown oxide were unsatisfying due to problems with the specimen preparation. However, a tendency for the damage development were seen. The finite element calculations gave values for the energy release rate the stress intensity factors in mode~I and mode~II that can be used in the life model. The tensile test showed that the failure mechanism is dependent of the coating thickness and it gave a rough value of the maximum strain acceptable.
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Influences of the Graphite Phase on Elastic and Plastic Deformation Behaviour of Cast IronsSjögren, Torsten January 2007 (has links)
The amount and morphology of the graphite phase largely controls the resulting properties of cast iron. For instance, in flake graphite cast irons the mechanical properties are low while the thermal conductivity is high. This is in contrast with spheroidal graphite cast irons where the mechanical properties are high and the thermal conductivity is low. These differences are due to the different graphite morphologies and must be accounted for in the design work and material selection of cast iron components. In this work the influence of the graphite phase on the elastic and plastic deformation behaviour of cast irons has been studied. The material grades studied originate from castings for marine diesel engine piston rings with different chemical analyses. Two groups of pearlitic cast iron materials were studied; one with differences in graphite morphology and one with grey irons that differed in graphite content. For these different material grades the mechanical properties were correlated to microstructural parameters. In addition to standard uniaxial tensile tests, acoustic emission measurements were used for the study of deformation. When studying the modulus of elasticity of the cast iron it was found that the modulus of elasticity of the inherent graphite phase depends on the roundness of the graphite particles and is due to the strong anisotropy of the graphite phase. A linear correlation between nodularity and the modulus of elasticity of the graphite phase was derived. This correlation made it possible to account for the anisotropy of the graphite phase in the model used. By applying the linear function when modelling the effective modulus of elasticity, a high accuracy between experimental and theoretical values was achieved. Another factor affecting the elastic response when subjecting a cast iron component to tensile load was found to be the plastic deformation that actually occurs at very low strains for all of the studied cast iron grades. It was observed that the plastic deformation in the low strain elastic region, quantified by using acoustic emission measurements, increased linearly with decreasing modulus of elasticity. These measurements showed that the amount of plastic deformation in the elastic region was largely controlled by the graphite morphology. It was concluded that as the roundness of the graphite particles increases, the plastic deformation activity in the elastic region decreases. The plastic deformation activity continued linearly into the pronounced plastic region of the tensile tests. A decrease in roundness or increase in graphite fraction resulted in an increase of the amount of plastic deformation and the strain hardening exponent. A dependence between strength coefficient and graphite fraction was observed. Models for the flow curves for pearlitic cast irons were developed and shown to accurately reproduce the observed experimental curves. The surveys performed and conclusions from this thesis will be helpful in the design of new cast iron materials.
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PlusTakJohansson, Ohlsson, Nilsson, Andreas, Johan, Arvid January 2010 (has links)
Today´s roofing of dwelling houses is a very time consuming procedure, which includes a lot of different steps on the construction site. Not only does it cost a lot of money, but often do problems with rot and mold occur in the attics of houses today. The use of prefabricated modules has seen a great breakthrough in the field of construction of dwelling houses; at least when it comes to foundations and walls, where this type of approach makes the construction process way more efficient. What no one previous has succeeded to develop is a corresponding system for roofs that meets the demands of a dwelling house. Accordingly the goal of PlusTak has been to come up with a proper module system for roofing of dwelling houses, where the roofing is completed to meet the demands of the Scandinavian market. During the project a lot of effort has been put into customer contacts and the usability of the product, as well in the manufacturing process as on the construction site. This development has gone hand in hand with several practical tests and tryouts. The project group has also participated in the use of PlusTak at various construction sites this spring, to get a better view of what could be further developed with the product. The outcome is a complete roofing system which is almost entirely prefabricated, and only requires a few hours on the construction site for completion of a fully weather protected roof. PlusTak is a very flexible system which is perfectly suitable for different house and roof types, and fits almost any roof pitch. The visible layer of the roof is available both as a classic seamed tin roof and with traditional tiles. Thanks to the great capability of insulation within the PlusTak system it suits the modern energy efficient houses perfectly. Moreover the insulation layer of the roof is placed in the outer roof, which eliminates the problems concerning condensation that occurs in weather and temperature changes, which has been a growing issue lately. Thus, PlusTak offers a cost-effective roof system of the as well as it provides a totally carefree ownership. An intense marketing campaign has been conducted through several channels during the development of the product. PlusTak was presented with great success at Nordbyggmässan in Stockholm, the biggest construction fair in Scandinavia, in March 2010. This was right after the product became patent pending. PlusTak has currently sold for over one million SEK and has been quoted on request for over 40 million SEK. The annual market in Sweden corresponds to over two billion, despite the current recession. The project group is counting on taking over 2-10% of that market within a period of five years. / Dagens takläggning vad gäller bostadshus är en tidskrävande process, där många olika steg ute på arbetsplatsen fordras vilket kostar mycket tid och pengar. Dessutom blir resultatet inte alltid vad man kunnat önska och röta och mögel är ett vanligt inslag på dagens vindar. Modulkonceptet har redan fått ett rejält genombrott inom nybyggnation av bostadshus, och prefabricerade husgrunder och väggar i modulform produceras och används idag i stor utsträckning. Detta modultänk effektiviserar byggnationerna avsevärt där man får det att fungera. Vad ingen tidigare lyckats med är att utveckla ett motsvarande taksystem som uppfyller alla de krav som ställs när det gäller bostadshus. Målet med Plustak har alltså varit att ta fram ett fullgott modulsystem för bostadshustak som uppfyller de nordiska kraven. Under projektet har projektgruppen lagt mycket tyngd på kundkontakter och användarvänlighet av produkten, både under tillverkning och på byggarbetsplatsen. Denna utveckling har gått hand i hand med en rad praktiska tester och försök. Projektgruppen har även varit med och lagt PlusTak vid flera tillfällen under våren för att vidareutveckla produkten ytterligare. Resultatet är ett komplett taksystem som är nästintill helt prefabricerat, och endast ett fåtal timmar krävs för att lägga ett helt tak på plats och erhålla en fullt väderskyddad byggnad. Plustak är mycket flexibelt och lämpar sig både för olika hus- och taktyper, och dessutom för nästintill alla taklutningar. Även som ytskikt finns olika utföranden i form av antingen klassisk bandtäckt plåt eller traditionella takpannor. Den goda isoleringsförmågan hos PlusTak gör att systemet väl uppfyller de krav som ställs på dagens lågenergihus. Att det isolerande skiktet dessutom är beläget ytterst i taket eliminerar kondensproblem som annars uppstår och som blivit ett växande problem för husägare. PlusTak erbjuder ett kostnadseffektivt taksystem som dessutom ger ett problemfritt takägande. Parallellt med utvecklingsprocessen av produkten har en offensiv marknadsföring bedrivits genom flertalet kanaler. I mars 2010 patentsöktes PlusTak, varefter det presenterades med stor framgång på Nordbyggmässan i Stockholm, nordens största byggmässa. I skrivande stund har PlusTak sålt för över en miljon kronor och offererats mot förfrågningar för över 40 miljoner kronor. Trots lågkonjunkturen motsvarar den årliga marknaden i Sverige minst två miljarder kronor och inom en femårsperiod räknar projektgruppen med att ha tagit över 2-10% av denna.
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