Dissertations / Theses on the topic 'Timber Materials'
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Cameron, Tony Ray. "Alaskan timber resources for wood-plastic composites." Pullman, Wash. : Washington State University, 2009. http://www.dissertations.wsu.edu/Thesis/Summer2009/t_cameron_070209.pdf.
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Thesis (M.S. in civil engineering)--Washington State University, August 2009.Title from PDF title page (viewed on Aug. 12, 2009). "Department of Civil and Environmental Engineering." Includes bibliographical references.
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Kawar, Alexandra(Alexandra Alba). "Comparative study of bracing patterns and materials for tall timber buildings." Thesis, Massachusetts Institute of Technology, 2020. https://hdl.handle.net/1721.1/127286.
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Thesis: M. Eng., Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, May, 2020Cataloged from the official PDF of thesis.
Includes bibliographical references (pages 77-81).
Exploration of new designs for urban environments is increasingly focusing on reducing carbon emissions generated by construction and operation of tall buildings. With recent technological advances in timber construction and its potential to mitigate the carbon embodied in structural materials, tall timber buildings are gaining acceptance as various forms are considered for their designs. Recently built and proposed buildings demonstrate the use of mass timber to resist gravity and lateral loads. There are inherent efficiencies in placing lateral load resisting systems on the perimeter of a structure along with the possibilities to integrate versatile geometric patterns and effective structural solutions. However, timber material properties may lead to elements of larger volume than those made of steel or concrete. This study compares structural stiffness gains and carbon emission reductions for exterior bracing created in timber and timber-steel hybrid configurations. Numerical analyses are used to explore braced frame geometries and layouts for the steel and timber elements, to predict structural response, and compare the effects of material placement.
by Alexandra Kawar.
M. Eng.
M.Eng. Massachusetts Institute of Technology, Department of Civil and Environmental Engineering
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Huang, Sheng. "Experiment study of the mechanical properties of timber materials under various humidity condition." Thesis, University of Macau, 2018. http://umaclib3.umac.mo/record=b3950672.
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Santana, Maria Elena, and n/a. "Eco-efficient timber use through bio-sensitive design." University of Canberra. Architecture and Building, 1998. http://erl.canberra.edu.au./public/adt-AUC20061107.164347.
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A significant number of building materials are based on wood. Wood
competes with other materials and products for many building applications
from structural framing to cladding. Wood appears to be preferable because
of its aesthetic and structural properties, its versatility, economic cost and
environmental benefits. However, timber wastage within the construction
industry is incalculable. Waste occurs at all stages of the timber resource
stream: procurement, conversion, installation, use, maintenance, dismantling
and eventual disposal. Much of this loss can be avoided through eco-design
strategies based on a better understanding of the total resource flows.
This thesis addresses the ecological implications associated with the use and
over-exploitation of timber in building construction. Applying bio-sensitive
design principles and using a life cycle approach, the thesis examines ways
of maximising timber resource yield through appropriate materials selection,
design strategies and construction techniques to reduce their ecological
footprint.
Finally, an easy-to-use guide that incorporates economic and aesthetic-value
criteria to the analysis is developed. The guide is aimed to offer a flexible
decision-support tool that enables designers and other people involved in the
construction industry to comprehend in a systematic way, the multiple
dimensions interacting when selecting timber-building products. It is thus,
intended to explore in practice the implications and trade-offs of state of the
art timber products with the ultimate aim of integrating the ecological
dimension to the decision-making process.
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Voth, Christopher Ray. "Lightweight sandwich panels using small-diameter timber wood-strands and recycled newsprint cores." Pullman, Wash. : Washington State University, 2009. http://www.dissertations.wsu.edu/Thesis/Fall2009/c_voth_120609.pdf.
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Thesis (M.S. in civil engineering)--Washington State University, December 2009.Title from PDF title page (viewed on Jan. 26, 2010). "Department of Civil and Environmental Engineering." Includes bibliographical references.
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Höök, Matilda. "Timber volume element prefabrication : production and market aspects /." Luleå : Luleå tekniska universitet, 2005. http://epubl.ltu.se/1402-1757/2005/65/.
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Isik, Aydin. "Disassembly And Re-use Of Building Materials: A Case Study On Salvaged Timber Components." Master's thesis, METU, 2003. http://etd.lib.metu.edu.tr/upload/1042431/index.pdf.
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The objective of this study was to investigate the feasibility of using salvaged timber from deconstructed buildings in Turkey. The intention was to show that the re-use of &lsquowaste&rsquo
materials, while decreasing the cost of construction also preserves the environment from wasteful and extensive use of natural resources. It is hoped that the findings of such a study will encourage professionals to use second hand timber components in Turkey. In order to deal with the waste problem and to save our planet the re-use of construction materials from economic, environmental, social, and historic points of views should be pursued. This research incorporated information about the re-use of timber, including ongoing projects around the world, as reported by the International Council for Research and Innovation in Building Construction (CIB) Task Group on Deconstruction (TG39), a local survey of individuals, organizations, and businesses that are related to the recycling and reuse of building materials. Local deconstruction works, recovery and re-use of timber elements and components were investigated on the basis of information obtained from the demolition contractors in Bentderesi locality in Ankara, a salvaged materials market. iii Moreover the study aimed to observe how used timber components are recovered from a demolition project. By observing the demolition of a building the author was able to determine the problems in recovering timber with the least damage. The findings of the investigation indicated that the architects and the building industry can play an important role to increase recovery rates and conditions of used timber components in construction, considerably. Instead of using nails for timber joints bolted connections should be preferred since they allow demounting and re-use with minimum damage during the deconstruction process. At the same time defects in timber due to extensive and unnecessary nailing can also be avoided. The decision on type of deconstruction, time and cost estimation, worker ability and sensitivity during disassembly influence the success of deconstruction. Tools and machinery used both on the work site and in the UBMs selling area have direct effects on the condition of recovered materials.
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Ng, Pui-ling Anna Laura. "Reduction of timber use in the Hong Kong construction industry to mitigate severe deforestation in tropical forests in Southeast Asia /." Hong Kong : University of Hong Kong, 2000. http://sunzi.lib.hku.hk/hkuto/record.jsp?B22284503.
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Checchia, De Ambrosio Giovanni. "Synthetic Redundancy - An adaptive, hi-res timber frame tectonics based on a digital materials strategy." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2017. http://amslaurea.unibo.it/14359/.
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Con questa tesi di ricerca si indagano le potenzialità di processi mereologici digitali applicati all’ architettura, generando sistemi complessi differenziati.L’obiettivo è quello di creare un sistema tettonico articolato, formato da elementi discreti e caratterizzati da una determinata morfologia e finite potenzialità di sviluppo e aggregazione. Si vuole indagare come un tale organismo può essere soggetto a logiche di auto-organizzazione e differenziazione sulla base di feedback esterni, coerentemente con vincoli di tipo costruttivo e materiale.Partendo da singole componenti orientate, dotate di limitate ma specifiche possibilità di movimento, il sistema ha capacità di organizzarsi e ordinarsi secondo logiche esclusivamente basate su interazioni locali e regole di allineamento, coesione e continuità strutturale, correlate agli altri elementi presenti nel network.
Il sistema, ispirato e guidato da un algoritmo che simula processi morfogenetici in diversi fenomeni biologici (Reaction-Diffusion Algorithm), è dotato di alta ridondanza e gerarchizzazione strutturale e ha la capacità di differenziarsi generando macro elementi, che, caratterizzati da prevalente sviluppo volumetrico o di superficie, permettono l’integrazione di elementi costruttivi standard in una possibile declinazione architettonica.
L’assemblaggio che ne risulta, complesso ed eterogeneo, costituito da elementi lamellari in legno, è capace di performance spaziali e strutturali, dispiegando le sue qualità nella capacità di auto-organizzarsi. Le strutture di cui è composto e i pattern che emergono sono frutto di regole locali, essendo stato deliberatamente scelto un approccio di tipo bottom-up per l’organizzazione del sistema.
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Gutshall, Scott T. "Monotonic and cyclic short-term performance of nailed and bolted timber connections." Thesis, Virginia Polytechnic Institute and State University, 1994. http://hdl.handle.net/10919/50106.
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This paper presents the results of testing to determine the appropriateness of the seismic load duration factor and to investigate the possible effect of previous load history from cyclic loading on connection reserve capacity and ductility. The single shear nail and bolt connection types tested represent common connection geometries used in wood construction in the United States. The results of two methods of fully reversing cyclic loading of connections are presented.
The first method was a load-controlled test with the applied cyclic loads acting at specified percentages above current nominal design values. The sets of specimens were then ramped to failure and the results were compared to a monotonic control set of specimens to determine if any reduction in connection capacity or ductility had occurred as a result of the cyclic loading. From the load-controlled cyclic testing, it was found that previous cyclic loading at load levels as high as twice current nominal design loads did not adversely affect connection capacity.
The second cyclic loading method was a displacement-controlled test that involved successive phases at increasing displacement levels. Each phase consisted of a peak displacement, followed by a series of three decay cycles, then by a series of three cycles at the original peak displacement, the third of which is used to determine the stabilized system. The process is repeated at increasing incremental levels of displacement. The phased displacement stabilized load-displacement curve was fit to an equivalent energy elastic-plastic system for determination of connection parameters. Results from the two cyclic test methods, and from monotonic testing, indicate that the current load duration factor for wind and seismic loading is justified.Master of Science
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Whale, L. R. J. "Deformation characteristics of nailed or bolted timber joints subjected to irregular short or medium term lateral loading." Thesis, London South Bank University, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.380658.
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Amigo, Jesus Menendez. "Optimisation of timber frame closed panel systems for low energy buildings." Thesis, Edinburgh Napier University, 2017. http://researchrepository.napier.ac.uk/Output/1035263.
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The United Kingdom published a legally binding document to reduce national greenhouse gas emissions by year 2020 up to 34% against the 1990 levels. This target also fulfils the Europe 2020 strategy of 20% carbon emission reductions by year 2020 (EC, 2010). Emissions due to space heating count for around 60% of the total domestic emissions (DCLG, 2012). The report “Rethinking Construction” published in 1998 emphasised the opportunities to improve the quality and efficiency of the UK construction sector (Egan, 1998). More recently, a framework has been published by the Government to tackle fuel poverty by building more energy efficient homes (DECC, 2015). In terms of energy performance, Passivhaus is recognised as one of the most energy efficient and researched construction standards which requires an exceptionally high-level of insulation and airtightness. Closed-panel timber frames are a relatively new system in UK with an opportunity for growth. These advanced panels are pre-fitted in the factory, reducing the on-site work. However, closed-panel systems present a more complex sole plate fixing detail which can have an undesirable long-term impact on the structural and thermal performance of the building. The work presented in this thesis investigates the structural considerations, racking performance, of timber frame closed panel systems for future building regulations. The thesis underlines the significance of structural stability, serviceability and detailing in relationship with long-term thermal efficiency and airtightness, according to Passivhaus standard. An experimental study was carried out to investigate the structural racking performance of advanced closed panel systems. A comparison was made between the behaviour of the timber frame panels and the analytical PD 6693-1. A set of different wall panel built-ups is presented for optimised Passivhaus design, including thermal bridge-free sole plate details. A timber frame racking software application was developed to optimise the structural design of shear walls. A parametric study was carried out with this tool to generate efficient timber frame wall design tables for different applied racking loads and U-values. The software application also allows for direct specification of robust sole plate base fixings and thermal bridge free details.
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Kouromenos, Alexandros. "Lateral Strength and Ductile Behavior of a Mortise-Tenon Connected Timber Frame." DigitalCommons@CalPoly, 2017. https://digitalcommons.calpoly.edu/theses/1790.
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The primary goals of this project were to examine the amount of lateral force resisted by a single-bay mortise-tenon connected timber moment frame, and to introduce ductile behavior into the mortise-tenon connections by adding a steel sleeve around a traditional wood peg. This research aimed to provide proof that traditional timber frames are capable of ductile racking while reliably complying with ASCE 7-10 building code drift speci! cations, implying an increase in the ASCE 7-10 ductility factor (R) for wood frames when used as lateral force resisting elements. A secondary goal was to promote traditional heavy timber framing as a main structural system. Modern structural framing is dominated by light-wood, steel, and concrete framing. The exploration in this project aspires to demonstrate that heavy timber frames can achieve comparable lateral performance and frame behavior to other current lateral systems, reassuring the reliability of traditional timber frames.
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Wahlers, John Colin. "A study of the extrusion of particulate cellulosic composite materials." Thesis, Brunel University, 1988. http://bura.brunel.ac.uk/handle/2438/7868.
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Traditional routes to the manufacture of timber based composite materials such as particleboard rely on platen pressing a premix of carefully chosen and prepared timber particles and an adhesive to produce flat sheets. Historically such routes have made very inefficient use of forest resources, and because of the planar nature of the composite produced, the finished articles have enjoyed a reputation of being of poor quality and "cheap". The work documented in this thesis sought to examine alternatives to the traditional manufacturing methods in terms of both raw materials and processing route, and to establish technical, economic, and environmental boundaries for the use of the alternatives. Having settled upon extrusion as the most likely technique with which to proceed, the investigation was carried forward by the construction of a series of experimental instruments with the joint aims of refining the technique to a realistic working level and investigating the underlying mechanical principles behind the process. Recourse to the literature of polymer rheology, fluid mechanics, and soil mechanics gave the basis for a crude mechanism hypothesis, and iterative improvements in the instrumental techniques yielded data with which this could be refined. Although some correlation between the extrusion behaviour of this system with other more easily quantifiable systems was found, there is still considerable work required in defining the dynamic changes in the material properties as the raw material is extruded. Small scale production experiments proved successful, however, and an elementary financial model of a suitable production facility indicated that the techniques developed could be used as the basis of an environmentally acceptable, economically viable, low technology industry.
15
Ng, Pui-ling Anna Laura, and 吳佩玲. "Reduction of timber use in the Hong Kong construction industry to mitigate severe deforestation in tropical forests in Southeast Asia." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2000. http://hub.hku.hk/bib/B31260342.
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Rask, Fredrik. "Life Cycle Assessment and comparison of the climate impact of structural members and floor systems constructed in concrete, steel and timber." Thesis, KTH, Byggnadsmaterial, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-256506.
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In this report the climate impact is determined for some basic structural elements made in steel,>mber and concrete. The aim is to compare the climate impact of these three building materials byquan>fying the emissions related to the produc>on and construc>on of some typical structures.The comparison comprise two parts, were one is the comparison of members in bending,compression and tension and the other part is the comparison of a couple of floor structures.The emissions are determined through a Life Cycle Assessment, LCA. The members are comparedwith respect to their load bearing resistance and the floor structures is compared per square meter.The mo>va>on for this inves>ga>on is that the construc>on industry is a large contributor to the totalamount of greenhouse gas emissions and in order to reduce these emissions new solu>ons andprac>ses must be adopted. A more thoughVul choice of the materials used in structures has thepoten>al of reducing the emissions.The method of determining the climate impact is based on first determining the material quan>>esfor all the inves>gated structures and then calcula>ng the amount of carbon dioxide equivalentsrelated to the produc>on of these materials with the help of a Life Cycle Assessment.The material quan>>es of the structural members is determined based on the load. The dimensionsof the cross sec>on is determined with respect to the required load resistance. The materialquan>>es of the floor structures is based on some exis>ng solu>ons from manufacturers.The study show that the >mber based design solu>ons almost always has a smaller climate impactand that the differences can be considerable. Members made in steel oZen result in very largeamount of greenhouse gas emissions but the sca[er in the results indicate that the origin of the steelhas great importance. Primary steel has a much larger impact as opposed to recycled steel.The comparison of the floor designs show that beyond the material choice itself, also the materialefficiency is important. The hollow core slab made in concrete is a very material efficient design andmay in some cases be on par with >mber based designs.The massive >mber floors made of Cross Laminated Timber, CLT, has a fairly large climate impactbecause of the sheer volume of material and may be on the same level as the floor made in concretefor some scenarios. There is however a wide range in the result based on whether the material istransported a long distance and depending on the choice of insula>on material. If these choices isop>mised, the emissions of the CLT floor is instead on a much lower level, closer to that of the otherlightweight floors inves>gated.The process of evalua>ng and comparing the material choices and structural designs form a lifecycleperspec>ve can be u>lised during the design in order to reduce the emissions. With a be[erknowledge of the climate impact of the design, be[er choices can be made in order to reduce theemissions.
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Peñaloza, Diego. "Exploring climate impacts of timber buildings : The effects from including non-traditional aspects in life cycle impact assessment." Licentiate thesis, KTH, Byggnadsmaterial, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-161193.
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There is an urgency within the building sector to reduce its greenhouse gas emissions and mitigate climate change. An increased proportion of biobased building materials in construction is a potential measure to reduce these emissions. Life cycle assessment (LCA) has often been applied to compare the climate impact from biobased materials with that from e.g. mineral based materials, mostly favouring biobased materials. Contradicting results have however been reported due to differences in methodology, as there is not yet consensus regarding certain aspects. The aim of this thesis is to study the implications from non-traditional practices in climate impact assessment of timber buildings, and to discuss the shortcomings of current practices when assessing such products and comparing them with non-renewable alternatives. The traditional practices for climate impact assessment of biobased materials have been identified, and then applied to a case study of a building with different timber frame designs and an alternative building with a concrete frame. Then, non-traditional practices were explored by calculating climate impact results using alternative methods to handle certain methodological aspects, which have been found relevant for forest products in previous research such as the timing of emissions, biogenic emissions, carbon storage in the products, end-of-life substitution credits, soil carbon disturbances and change in albedo. These alternative practices and their implications were also studied for low-carbon buildings. The use of non-traditional practices can affect the climate impact assessment results of timber buildings, and to some extent the comparison with buildings with lower content of biobased building materials. This effect is especially evident for energy-efficient buildings. Current normal practices tend to account separately for forest-related carbon flows and aspects such as biogenic carbon emissions and sequestration or effects from carbon storage in the products, missing to capture the forest carbon cycle as a whole. Climate neutrality of wood-based construction materials seems like a valid assumption for studies which require methodological simplification, while other aspects such as end-of-life substitution credits, soil carbon disturbances or changes in albedo should be studied carefully due to their potentially high implications and the uncertainties around the methods used to account for them. If forest phenomena are to be included in LCA studies, a robust and complete model of the forest carbon cycle should be used. Another shortcoming is the lack of clear communication of the way some important aspects were handled.QC 20150310
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Wadi, Husam. "Structural behaviour of lateral load-carrying capacity of timber frame walls filled with hemp concrete : experimental study and numerical analysis." Thesis, Université Clermont Auvergne (2017-2020), 2019. http://www.theses.fr/2019CLFAC038/document.
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Les projets de construction sont aujourd'hui confrontés à des défis importants pour réduire la grande quantité d'énergie employée quotidiennement pour les utilisations tels que le chauffage, l'électricité et l'eau chaude dans les bâtiments résidentiels et commerciaux, en particulier en Europe. De nombreux règlements de construction encouragent l'utilisation des matériaux biosourcés puisqu’ils semblent avoir des propriétés physiques supérieures en terme d'efficacité énergétique dans le secteur de la construction. L'utilisation de matériaux à faible teneur en carbone dans des structures telles que le béton de chanvre améliore le niveau d'isolation ainsi que l'absorption acoustique et diminue le poids de la structure du bâtiment, car ce matériau naturel fournit un agrégat à faible densité. Cette étude concerne le comportement mécanique de murs en bois, réalisés avec des planches croisées en bois CLT et des murs à panneaux d’OSB, sous l’effet de forces horizontales de cisaillement. Une approche théorique a été proposée pour prédire la performance latérale de la paroi CLT par rapport aux charges latérales ainsi qu’une comparaison entre les résultats théoriques et expérimentaux a été effectuée. Des essais expérimentaux ont été réalisés sur des murs de bois ayant deux formes différentes pour étudier et mettre en évidence les paramètres qui affectent significativement la résistance latérale du béton de chanvre en tant que matériau de remplissage. Des montants verticaux et des éléments de contreventement diagonaux de 2,5 mètres de hauteur et 1,25 mètres de largeur soumis à une compression ont été réalisés dans cette étude . Les résultats ont montré que le béton de chanvre apporte une légère contribution contre les charges latérales dans les murs verticaux de 1,25 mètres de largeur, ce qui signifie qu'une diminution de la largeur du mur de bois diminue significativement la contribution du béton de chanvre contre les charges latérales. Trois murs en bois de différentes longueurs (1,2 mètres, 1,6 mètres et 2,4 mètres) remplis de béton de chanvre ont été étudiés numériquement dans cette étude. D'après les résultats numériques, il était évident que la largeur du mur en bois joue un rôle principal dans la résistance latérale du béton de chanvre : lorsque la largeur du mur augmente, la résistance latérale du béton de chanvre s’accroît considérablement. De plus, le contact et la liaison entre le chanvre et les montants en bois affectent totalement la capacité de la résistance latérale du béton de chanvre en tant que matériau de remplissage dans les murs en boisConstruction projects nowadays face significant challenges to reduce the large amounts of daily energy usage for utilities such as heating, electricity and hot water in residential and commercial buildings – especially in Europe. Many building regulations encourage the use of bio-based materials with superior physical properties for energy efficiency in the construction sector. The use of low-carbon material in structures such as hemp concrete, improves the insulation level and sound absorption and simultaneously decreases the weight of the building structure, as this natural material provides low-density aggregate. This study aimed to investigate the mechanical behaviour of timber frame walls against lateral loads. Cross-laminated timber walls (CLT) and Oriented Strand Board (OSB) were used in this study in order to examine the global lateral strength of timber walls. A theoretical approach has been proposed to predict the lateral performance of CLT wall against lateral loads and a comparison between the theoretical and experimental results has been conducted. Experimental testing was undertaken on a full-size example of two different designs of timber walls to investigate and highlight the parameters that significantly affect the lateral resistance of hemp concrete as infill material. Vertical studs and diagonal bracing elements under compression were used in this study, with dimensions of 2.5m height and 1.25m length. The results showed that hemp concrete makes a slight contribution against lateral loads in vertical stud timber wall of length 1.25m, which means that decreasing the length of timber wall significantly decreased the hemp concrete contribution against lateral loads. Three timber walls with different lengths (1.2m, 1.6m and 2.4m) filled with hemp concrete have been examined numerically in this study. Based on the numerical results, it was obvious that the length of the timber wall plays a major role in the lateral strength of hemp concrete, as increasing the wall length significantly increased the lateral strength of hemp concrete. Also, the contact and bonding between hemp material and timber studs significantly affected the lateral load carrying capacity of hemp concrete as infill material in timber frame walls
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Córdova, Franciele Oliveira de. "Desempenho tecnológico de vigas em madeira laminada colada de paricá (Schizolobium amazonicum) tratadas quimicamente." Universidade do Estado de Santa Catarina, 2015. http://tede.udesc.br/handle/handle/1946.
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Structural elements in glued laminated timber (GLT) are made mostly with exotic wood from planted forests. However, are little studies to evaluate the performance of native forest species planted in Brazil for use in GLT. This work aims to evaluate the technological performance of the native species of planted forest, paricá (Schizolobium amazonicum) in the composition of beams GLT, chemically treated. Assays were performed to mechanical characterization, as well as its preservation and performance by gluing. It was conducted three treatments: GLT beams without chemical treatment; GLT beams with blades chemically treated and GLT beams chemically treated after bonding of untreated blades. The beams were of approximate dimensions 5,0x10,0x240,0 cm consisting of four blades. The position of the blades according to the classification given by way of non-destructive testing has been determined that the modulus of elasticity. A comparison between the analytical strain was performed by means of this particular section of the Homogenization Method (HMS) and experimental deformation determined by this bending test at four points. Experiments with GLT paricá chemically immunized, showed that there is no significant resistance loss, being equivalent to MLC beams treated and untreated chemically, and your collage is also not affected by the chemical treatment. Based on the results, it can be stated that both the chemical treatment blades such as the treatment of GLT beam as the whole, do not significantly affect the mechanical performance of the beams in GLT paricá
Elementos estruturais em madeira laminada colada (MLC) são constituídos, em sua maioria, com madeiras exóticas de florestas plantadas. Entretanto, são poucas as pesquisas que avaliem o desempenho de espécies nativas de floresta plantada no Brasil para uso em MLC. Este trabalho tem como objetivo avaliar o desempenho tecnológico da espécie nativa de floresta plantada, o paricá (Schizolobium amazonicum) na composição de vigas em MLC, tratada quimicamente. Foram realizados ensaios para caracterização mecânica, bem como o seu desempenho mediante a preservação e a colagem. Foram realizados três tratamentos: vigas MLC sem tratamento químico; vigas MLC com lâminas tratadas quimicamente e vigas MLC tratadas quimicamente depois da colagem de lâminas não tratadas. As vigas eram de dimensões aproximadas de 5,0x10,0x240,0 cm compostas por quatro lâminas. A posição das lâminas se deu conforme classificação por meio de teste não destrutivo em que foi determinado o módulo de elasticidade. Foi realizada uma comparação entre a deformação analítica, esta determinada por meio do Método de Homogeneização da Seção (MHS) e deformação experimental, esta determinada por meio de ensaio de flexão a quatro pontos. Os experimentos com MLC de paricá imunizado quimicamente, mostraram que não houve perda de resistência significativa, sendo equivalentes para vigas MLC tratadas e não tratadas quimicamente, e sua colagem também não é prejudicada pelo tratamento químico. As deformações analíticas e experimentais também foram equivalentes. Com base nos resultados pode-se afirmar que tanto o tratamento químico de lâminas, como o tratamento da viga MLC como o todo, não afetam significativamente o desempenho mecânico das vigas em MLC de paircá
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Vrazel, Matthew Eric. "The effects of species, adhesive type, and cure temperature on the strength and durability of a structural finger joint." Thesis, Mississippi State : Mississippi State University, 2002. http://library.msstate.edu/etd/show.asp?etd=etd-05152002-122630.
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Archila, Santos Hector Fabio. "Thermo-hydro-mechanically modified cross-laminated Guadua-bamboo panels." Thesis, University of Bath, 2015. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.675700.
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Guadua angustifolia Kunth (Guadua) is a bamboo species native to South and Central America that has been widely used for structural applications in small and large-scale buildings, bridges and temporary structures. Currently, its structural use is regulated within seismic resistant building codes in countries such as Peru and Colombia. Nevertheless, Guadua remains a material for vernacular construction associated with high levels of manual labour and structural unpredictability. Guadua buildings are limited to two storeys due to the overall flexibility of the slender and hollow culms and its connection systems. Its axial specific stiffness is comparable to that of steel and hardwoods, but unlike wood, Guadua’s hollow structure and lack of ray cells render it prone to buckling along the grain and to transverse crushing. As a result, Guadua’s mainstream use in construction and transformation into standard sizes or engineered Guadua products is scarce. Therefore, this work focussed on the development of standardised flat industrial structural products from Guadua devising replicable manufacturing technologies and engineering methods to measure and predict their mechanical behaviour. Cross-laminated Guadua panels were developed using thermohydro-mechanically modified and laminated flat Guadua strips glued with a high performance resin. Guadua was subjected to thermo-hydro-mechanical (THM) treatments that modified its microstructure and mechanical properties. THM treatment was applied to Guadua with the aim of tackling the difficulties in the fabrication of standardised construction materials and to gain a uniform fibre content profile that facilitated prediction of mechanical properties for structural design. Densified homogenous flat Guadua strips (FGS) were obtained. Elastic properties of FGS were determined in tension, compression and shear using small-clear specimens. These properties were used to predict the structural behaviour of G-XLam panels comprised of three and five layers (G-XLam3 and G-XLam5) by numerical methods. The panels were assumed as multi-layered systems composed of contiguous lamellas with orthotropic axes orientated at 0º and 90º. A finite element (FE) model was developed, and successfully simulated the response of G-XLam3 & 5 panels virtually loaded with the same boundary conditions as the following experimental tests on full-scale panels. G-XLam3 and G-XLam5 were manufactured and their mechanical properties evaluated by testing large specimens in compression, shear and bending. Results from numerical, FE predictions and mechanical testing demonstrated comparable results. Finally, design and manufacturing aspects of the G-XLam panels were discussed and examples of their architectural and structural use in construction applications such as mid-rise buildings, grid shells and vaults are presented. Overall, this research studies THM treatments applied to Guadua in order to produce standardised engineered Guadua products (EGP), and provides guidelines for manufacturing, testing, and for the structural analysis and design with G-XLam panels. These factors are of key importance for the use of Guadua as a mainstream material in construction.
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Parrott, Jordan A. "Timbre Architecture: The Glitch is the System." University of Cincinnati / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1243013919.
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Mohamed, Ahmed S. "Photogrammetric and stereo vision techniques for evaluating material properties in timber and timber-based composite structures." Thesis, Edinburgh Napier University, 2016. http://researchrepository.napier.ac.uk/Output/462281.
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A fundamental requirement for efficient use of a glulam beam is an accurate knowledge of its mechanical behaviour and the material properties characterising that behaviour. It becomes extremely important to obtain accurate measurements of material properties ofglulam, but this can be challengeable, especially for commonly used properties, such as the modulus of elasticity and shear modulus. Experiment testing is the way to determine elastic properties, however, the problem of experimentally determining appropriatevalues of these properties for timber-based composite is not as simple and straightforward as in isotropic materials, and care must be taken in the experimental methods used in determining their values. There is a need to develop an appropriate method in order to evaluate these properties. Unlike the traditional methods in whichcontact devices such as inclinometers or linear variable differential transducers are used to identify the material properties of glulam by utilizing their measurements of displacements and rotations at specific points, the optical methods provide an efficient and accurate approach for measuring these properties at multi-location so that more regions of interest can be monitored simultaneously without contact. Moreover, the traditional devices are limited to give measurements in one or two dimensions whereas the optical methods can be used to gain measurements in three dimensions. Although the optical techniques were successfully applied to different structural applications, little work has been done on the area of evaluating material properties of timber, especially modulus of elasticity and shear modulus. Therefore, the primary motivation of this project will be allocated to evaluate those properties utilizing the stereo vision approach. This thesis describes the research work in which a stereo camera system combined with a photogrammetric approach was proposed to evaluate material properties of timber and timber-based composite joists. A series of experiments were conducted to investigate the applicability of the approach to evaluate different material properties of glulam beams under different types of tests, including the torsion and the compression. Remarkable findings were obtained which might help for developing an outline for a future research programme in the field of evaluating material properties of glulam, allowing investigating the relationship between these properties. The results also showed that the optical system not only allowed assessing performance and reliabilityof the traditional sensors, but also allowed monitoring the deformation of the samples at various locations by providing more information which would not be possible to obtain using the traditional techniques.
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Alkhado, Luqman, and Youcef Boussaa. "Heat transfer tests on EPS material and massive timber wall component." Thesis, Högskolan Dalarna, Energiteknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:du-28673.
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Timber walls are known to be an energy efficient component in the building envelope. These building elements are essential in the passive design and have been pointed out to their ability to regulate the indoor climate and reduce energy demand. Heat transfer measurements of thermal transmittance value of Iso-timber wall component have been performed with the climate chamber at three temperature differences. The influence of temperature variations on the thermal conduction of the wall were investigated. The temperature on the warm side was kept at room temperature 20 °C while the cold side temperature was decreased from 0 C to -20 C during the tests. As the temperature difference is increased, the thermal transmittance value of the timber wall component decreased slightly due to decrease in the thermal conductivity value. The effect of density and porosity on the thermal conductivity may be related to the presence of air voids and cell boundaries inside the timber wall. Results have showed that the U-value of the timber wall component decreases at higher temperature differences which indicates the higher degree of insulation of the timber wall component.
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Ratto, Diego. "Electroacoustic Orchestration : Timbre, Space and Sound Material Organisation." Thesis, Kungl. Musikhögskolan, Institutionen för komposition, dirigering och musikteori, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kmh:diva-3144.
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As a composer of electroacoustic music, I’m interested in understanding which characteristics of classical orchestration can be used in electroacoustic music after these years of its development. In specific, which aspects of orchestration can be used as powerful techniques in acousmatic music? The aim of this study is to create connections between the conventional acoustic orchestration practice and electroacoustic orchestration by using a transfer2 technique.
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Jantan, Mohd Dahlan. "Chemical preservation of some refractory timber species of Malaysia." Thesis, University of Portsmouth, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310381.
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The treatability of six Malaysian timbers namely Red Balau (Shorea guiso), Kapur (Dryobafanops aromatica), Kasai (Pometia pinnata), Kulim (Scorodocarpus borneensis), Kempas (Koompassia malaccensis) and Keruing (Dipterocarpus grandiflorus) using the applied pressure processes (oscillating pressure, conventional Bethell and a modified Bethell process) was investigated. Treatments were carried out with a commercial water-borne copper-chromearsenic (CCA) preservative, known as Celcure-AP. The conventional Bethell process was the most effective method of wood treatment followed by the modified Bethell and the oscillating pressure process. While sufficient preservative retention and absorption was achieved in Kempas and Keruing to meet the Malaysian Standard MS 386 : 1986 specifications for exterior timber used in ground contact, the other four timbers - Red Balau, Kapur, Kasai and Kulim did not fulfil this requirement, even when treated at the most extreme treatment conditions. Using the three pressure processes, seasoning period and treatment time were found to have significant effects on preservative retention and penetration in all timber species. Investigations into the effect of three pretreatment procedures - steaming, incising and ponding to improve the treatability of the six timber species were carried out. Incising was the most effective pretreatment procedure in enhancing the treatability of these timbers. However, at the highest incising density employed (4,500 incisions/m2), it was still not possible to treat Red Balau, Kapur, Kasai and Kulim timber to achieve satisfactory target preservative retention and penetration. The less effective incising procedure was due mainly to the low incising density used. The possibility of improving the treatability of these four timber species further using higher incising densities and other methods of inCising pretreatment is discussed. Steaming, incising and ponding pretreatments had a pronounced effect on the strength properties of timbers based on reduction of their modulus of elasticity (M.D. E.), modulus of rupture (M.O.A.), compressive strength and hardness. The highest strength losses were observed in timbers that had been ponded for 6 months. Significant strength losses were also observed in incised and steamed timbers, but the magnitudes were lower than the 6 month ponding regime. This was attributed to low incising density and the short steaming period. The performance of Celcure-AP in the six timber species was evaluated in laboratory and field tests. In addition, a copper-azole formulation (Tanalith-3485) was also evaluated on Kempas timber. Laboratory tests involved exposure of treated wood blocks to five decay fungi - Pycnoporus sanguineus, Trametes versicolor, Coniophora puteana, Gloeophyllum trabeum and Oligoporus placenta. The less durable timbers - Kempas and Keruing needed a higher loading of Celcure-AP in order to give equal performance compared to the more durable timbers - Red Balau, Kapur, Kasai and Kulim. Based on copper retention in treated samples, a higher loading of Tanalith-3485 was required in Kempas to achieve comparable results to Celcure-AP treated samples. However, the concentration levels of Tanalith-3485 used in the present study were sufficient to afford protection to Kempas stakes exposed for 36 months in the field test. A longer exposure period is however, recommended for a full evaluation of timber/preservative combinations against wood deteriorating organisms under Malaysian conditions. In the field test, soft rot fungi were the main causal organisms in the attack of timbers in test site A (fungal test bed), while in test site B stake failure was due mainly to termite attack.
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Rininger, Zachary Scott. "The utilizaton of small diameter timbers in pultruded long strand composites." Online access for everyone, 2008. http://www.dissertations.wsu.edu/Thesis/Summer2008/Z_Rininger_072108.pdf.
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Pearson, Hannah. "Strut and tie modelling of cross-laminated timber panels incorporating angular material properties." Thesis, University of Bath, 2015. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.667741.
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The use of Cross-Laminated Timber products has increased in recent years with a range of structural applications including CLT tall buildings and folded structures. As CLT is used in more innovative structural applications the need for specific methods of design and analysis are apparent. A review of the literature demonstrates that despite the increasing popularity of CLT in construction there are limited methods for the design and analysis of CLT panels and structures that fully utilise its unique properties. Manufacturer data relating to the CLT material properties varies how the cross directional laminas are considered. Finally it was found that there is limited published knowledge regarding CLT material properties for panels loaded non-tangentially to the direction of the timber grain. A method for predicting failure loads and modes has been presented and compared with experimental test data. A Strut and Tie model is proposed for the analysis of CLT panels, a methodology originally developed to design of reinforced concrete deep beams. The Strut and Tie approach considers panel geometry, loads, supports, different properties in tension and compression and was adapted to consider anisotropic behaviour. The procedure, advantages and limitations have been presented and a model developed for an application in CLT. The use of this model is considered for the analysis of simple CLT panel loadings. The behaviour of CLT at different timber grain angles demonstrate a complex composite behaviour influencing the strut and tie capacities. The definition of node sizes was also found to be critical to the definitions of the struts and ties and hence the capacity of the sections. Comparison of experimental tests to the model demonstrates some application to using a Strut and Tie in CLT panels. It identifies where additional investigation is required to improve, develop and validate the model into a method that may be used for full-scale CLT panels and structures in design practice and consider a variety of geometries and loading arrangements.
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van, Beerschoten Wouter Adrian. "Structural Performance of Post-tensioned Timber Frames under Gravity Loading." Thesis, University of Canterbury. Department of Civil and Natural Resources engineering, 2013. http://hdl.handle.net/10092/8735.
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A new structural system for multi-storey timber buildings has been developed over the last seven years at the University of Canterbury. The system incorporates large timber structural frames, whereby semi-rigid beam-column connections are created using post-tensioning steel tendons. This system can create large open floor plans required for office and commercial buildings.
Several material properties of the engineered timber used were determined based on small-scale experimental testing. Full-scale testing of beams, connections and frames resulted in a more comprehensive understanding of the behaviour of such systems. Numerical, analytical and framework models also led to the development of design equations and procedures which were validated with the acquired experimental data.
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Aparicio, German Walter Jr. "Holzbau : timber construction and material information exchanges for the design of complex geometrical structures." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/59105.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Architecture, 2010.Page 77 blank. Cataloged from PDF version of thesis.
Includes bibliographical references (p. 74).
In a universe made of bits where everything is continuously computing and nature itself is processing information everyday, what is it that our materials compute? Specifically, what are the bits of information registered within timber? More importantly, in this universe made of bits how do we design using this information and how do we imagine new buildings? This thesis explores the use of wood as a natural material in the design and construction of complex geometrical timber structures by capturing the natural curvature found in timber into digital data and building a framework for surface timber mapping as a design method. Key results include a detailed framework for translation, method for timber mapping and a prototype utilizing this method. Future steps include growth of timber structures and the use of living material in combination with typical timber construction methods for the design and construction of future buildings.
by German Walter Aparicio Jr.
S.M.
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Brose, Andrew(Andrew John). "Peripheral timber applications for waste wood material in extreme climates and earthquake risk regions." Thesis, Massachusetts Institute of Technology, 2018. https://hdl.handle.net/1721.1/122902.
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This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Thesis: S.M. in Architecture Studies: Building Technology, Massachusetts Institute of Technology, Department of Architecture, 2018
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 63-66).
Worldwide, discarded construction and demolition material account for 40% of all municipal solid refuse including residential, commercial, institutional, and agricultural waste flows (Elgizawy, El-Haggar, and Nassar 2016). Hong Kong sends over 200 tons of timber waste from old formwork and scaffolding to the landfill per day (Wang et al. 2016). After fulfilling their assumed raison d'etre, the cement-flaked shuttering boards and stubby scaffolding poles arrive amongst the discards, eventually deformed beyond utility. This thesis explores the possibilities of reusing wood that sits at the fringe of construction projects, in applications that bring back the beauty and elegance ingrained in the oldest of building material. In part, this project is a remolding of the perception of undervalued wood species and construction waste. This research proposes specific techniques, inculcating value into discarded wood material and bringing a new mechanism for the material production of timber existing at the periphery of design and construction. In application, this study considers solutions around natural fiber composites and timber space-frame roofs for affordable housing projects. A prototype space-frame using small diameter wood elements was constructed in India and made practical by the development of a simple joint system. Load testing of the frame provided positive results (2.3 kN/m²) and surpassed India National Building Code standards for roof design. In addition, waste wood fibers incorporated in cementitious wall and roof panels improved thermal insulation properties (0.164 W/m²·K) while increasing flexural strength (4.6 N/mm²). Prototype and samples were tested within the objectives of improved thermal comfort, increased earthquake safety, and reduced material cost.
by Andrew Brose.
S.M. in Architecture Studies: Building Technology
S.M.inArchitectureStudies:BuildingTechnology Massachusetts Institute of Technology, Department of Architecture
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Špačková, Eva. "Multifunkční objekt v Českých Budějovicích." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2016. http://www.nusl.cz/ntk/nusl-240487.
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The subject of this thesis is the design and assessment of the supporting structure multifunctional building in the Czech Budejovice . The construction of a sphere with a maximum diameter of 30 m and a height of 19.5 meters the highest point . The supporting structure consists of curved ribs , elevator shaft and ceiling beams . The structure is designed in 4 versions . Two variants are made of steel, the third option is wooden and the latest version solves a combination of wood and steel. In the variant selected is done loading , ultimate limit state, serviceability limit state , fire resistance and compounds selected details.
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Sanna, Fausto. "Timber modern methods of construction : a comparative study." Thesis, Edinburgh Napier University, 2018. http://researchrepository.napier.ac.uk/Output/1256099.
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The doctoral research revolves around a comparative study of timber modern methods of construction for low-rise, residential buildings in Scotland. The building techniques studied involve both timber-frame panel construction (open-panel and closed-panel systems and structural insulated panels) and massive-timber construction (cross-laminated and nail-laminated timber panels). A non-timber technique is also included in the study: more traditional, load-bearing masonry (blockwork). These different building techniques have been analysed from two complementary aspects: environmental impacts and thermal performance. The environmental study is based on the life-cycle assessment methodology and embraces various aspects: environmental impacts (e.g., climate change, acidification, eutrophication, ozone depletion, etc.), consumption of energy (renewable and non-renewable resources) and production of waste (from non-hazardous to radioactive). The assessment takes a cradle-to-gate approach and, in its structure and method, is informed by the current recommendations of the international standards in the field (i.e., ISO 14040 series). Various environmental trade-offs between construction methods have been identified. In terms of global-warming potential (excluding biogenic carbon sequestration), results suggest that timber-frame buildings show a better performance than masonry buildings; this is particularly true for the open-panel system, which emits about 10% less carbon than the masonry counterpart. Massive-timber buildings tend to cause more carbon emissions than masonry ones. In terms of consumption of non-renewable primary energy, timber buildings do not generally show significant advantages with respect to blockwork-based masonry. In particular, structural-insulated panel systems tend to show very high energy requirements. Timber-based buildings show a tendency to cause increased acidification, eutrophication and creation of low ozone than their masonry counterpart. The level of offsite fabrication that is employed for the erection of the buildings plays an important role in the magnitude of most environmental impacts, which show an average decrease between 5% and 10% when some of the operations are shifted from the construction site to the factory. v The thermal study investigates the performance of the building envelope, and, in particular, of external walls, by means of tests whereby the thermal behaviour of a sample of walls (of full-size section) has been observed and measured over time. On the outside, the walls were exposed to real, natural weather variations throughout the summer. The study especially focuses on the time-dependent response of three different walling systems (which results from their individual cross-sectional arrangements of building components and the associated combination of heat-storage capacity and thermal resistance): a timber-framed wall, a cross-laminated-timber wall and a masonry wall. Thus, the main goal of the study was to characterise the thermal-inertia parameters of these walls. This type of thermal behaviour is related to the repercussions of global climate change at UK level, especially in terms of increase in solar irradiance and temperature, which requires an adaptation of the building-envelope such that it can perform well both during wintertime and summertime, by providing maximum indoor comfort with minimum economic and environmental costs from the construction and operation of buildings. The timber-framed wall possesses the greatest capacity to slow down the propagation of temperature waves from the outer surface to the inner surface (time lag), whereas the masonry wall performs best with respect to reducing the amplitude of temperature oscillation on the inner surface (decrement factor). The cross-laminated-timber wall exhibits intermediate values of both time lag and decrement factor, relative to the other two walls. Both the thermal and life-cycle assessment of the construction alternatives aim at assisting the design and decision-making process in the residential field and at suggesting areas that need to be addressed and improved, towards a coherent evolution of the building techniques included in this study and a step forward in the realisation of sustainable, low-rise dwellings.
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Parucker, Fernando Falaster 1978, Jackson Roberto 1974 Eleotério, and Universidade Regional de Blumenau Programa de Pós-Graduação em Engenharia Florestal. "Modelagem e simulação da flexão estática de painéis Cross Laminated Timber pelo método de elementos finitos." reponame:Biblioteca Digital de Teses e Dissertações FURB, 2018. http://www.bc.furb.br/docs/DS/2018/364004_1_1.pdf.
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Orientador: Jackson Roberto Eleotério.Dissertação (Mestrado em Engenharia Florestal) - Programa de Pós-Graduação em Engenharia Florestal, Centro de Ciências Tecnológicas, Universidade Regional de Blumenau, Blumenau.
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Čáslava, Petr. "Šetrné bydlení na venkově." Doctoral thesis, Vysoké učení technické v Brně. Fakulta architektury, 2013. http://www.nusl.cz/ntk/nusl-233251.
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While I spent 7 years of study, experience and dedication to this work, the building construction has passed evolution from construction boom to contemporary building crisis. Demand for cheap building construction, materials and family housing increased sharply. Energy prices are rising every year... It seems that we will all have to deal with our essential task today or in the near future . This task is mean to prevent the current rate of degradation and destruction of our planet's climate and our environment. In this point of view, it looks the question of energy-saving construction very topical. By entering the study was to examine the possibilities of environmental friendly housing in rural areas in terms of environmental issues. My hypothesis was if can I determine the suitable candidate for the construction of passive houses themselves by comparing their characteristic of pre-defined construction samples. My objective is to offer builders and designers overview of suitable building systems with the possibility to compare the various factors influencing the decision on the selection of a builder´s construction for a house. The thesis presents the comparison of seven structural systems as a basic element of architecture. In the implementation of energy-efficient house is an architectural form often conditioned by structure. For this reason it is necessary to offer this kind of overview with options and parameters of individual building systems, which can then be used by architect to design a house for the builder - free and easy realization of his own, let´s say DIY (do it yourself). For builders (mean investors) of DIY houses is economy and finance a crucial question, therefore, for this reason I will evaluate suitable building system which is relative performance vs. price in the end. It is necessary to take into account the architecture of the house and especially the space layout and design and the attitude with the context of the rural areas environment. My pupose was to prove that good architectural design can be used with of low-cost, energy-saving and environmental friendly house built in DIY way.
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Lessa, Rafael 1984, Jackson Roberto 1974 Eleotério, and Universidade Regional de Blumenau Programa de Pós-Graduação em Engenharia Florestal. "Viabilidade técnica do uso de madeira de Pinus taeda e Eucalyptus grandis na fabricação de painéis CLT - Cross Laminated Timber." reponame:Biblioteca Digital de Teses e Dissertações FURB, 2017. http://www.bc.furb.br/docs/DS/2017/363172_1_1.pdf.
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Orientador: Jackson Roberto Eleotério.Dissertação (Mestrado em Engenharia Florestal) - Programa de Pós-Graduação em Engenharia Florestal, Centro de Ciências Tecnológicas, Universidade Regional de Blumenau, Blumenau.
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Lively, Jason M. "In Situ Ion Exchange in a Micro-porous Transition Metal Silicate Framework." TopSCHOLAR®, 2016. http://digitalcommons.wku.edu/theses/1730.
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Ion selectivity of minerals has traditionally been utilized in industry as a catalyst, metal separation, and environmental reclamation/sequestration tool. There is an increased interest in understanding ion selectivity mechanisms of micro-porous minerals and mineral-like structures and how they can be applied in various industries: environmental and, potentially, pharmaceutical. This study seeks to understand the ion exchange mechanisms in micro-porous zirconosilicates using time-resolved Raman spectroscopy and X-ray diffraction. The thesis material was exchanged with H+, Na+, K+, and Cs+ in order to better understand structural changes as well as the influence of the H+-bonding during the exchange process. It is hypothesized that the host (H+) ion strongly influences the ion selectivity of the mineral by changing framework polyhedra and ring geometry, and the geometry of the interstitial the OH…H2O bond network to only allow cations of certain sizes through the channels. In addition, the H+ may repel cations with high charge densities from entering the extra-framework sites in the crystal structure by protonating the channel pathways.
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Tyrstam, Sabina. "Påverkas bottenfaunan av att timmer lagras i sjöar? En studie i Kisasjön efter stormen Gudrun." Thesis, Linköping University, The Department of Physics, Chemistry and Biology, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-11602.
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Stormen 2005 drabbade södra Sverige och skövlade nästan 70 miljoner m3 timmer på en natt, varför mycket timmer lagrades i Kisasjön. Syftet med detta arbete är att undersöka om bottenfaunan i Kisasjön påverkats av timmerlagringen genom låga syrehalter och ändrat bottensubstrat. Även den närbelägna Knoppetorpssjön dit Kisasjöns vatten rinner undersöktes. På vardera tio djup under språngskiktet i varje sjö togs fem ekmanhugg. Syreförhållandena mättes vid varje lokal och sedimentet beskrevs. Syrehalten var nära noll vid botten på lokaler djupare än 6 m redan tidigt under sommaren. Totalt fångades 2136 individer fördelade på 10 taxa. Sjöarna innehöll i stort sett samma taxa men antalet individer skiljde. Chaoborus flavicans
dominerade i Knoppetorpssjön och ökade med djupet, medan de andra grupperna var vanligare på mindre djupt vatten. Oligochaeta dominerade i Kisasjön och minskade med djupet. Chironomini och C. flavicans vara dock något vanligare på djupa bottnar. En tidigare undersökning i Kisasjön visade på liknande artsammansättning. Alla taxa är anpassade till ett liv i syrebrist. Oligochaeta,
Chironomidae och C. flavicans kan lagra syre för senare bruk. C. flavicans söker dagtid skydd undan fiskpredation nära den syrefria sedimenten, vilket troligen förklarar dess höga antal i Knoppetorpssjön. Lägre antal i Kisasjön kan bero på
förorenat vatten, kanske oljeutsläpp, medan Oligochaeta kan ha högre toleransnivå. Att det var färre Oligochaeta i Knoppetorpssjön kan bero på mindre mängd organiskt material (bark) där.
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Rival, Olivier. "Organic materials for quantum computation." Thesis, University of Oxford, 2009. http://ora.ox.ac.uk/objects/uuid:3674b9ce-c284-47b5-ab0d-76d094c849f0.
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Quantum mechanics has a long history of helping computer science. For a long time, it provided help only at the hardware level by giving a better understanding of the properties of matter and thus allowing the design of ever smaller and ever more efficient components. For the last few decades, much research has been dedicated to finding whether one can change computer science even more radically by using the principles of quantum mechanics at both the hardware and algorithm levels. This field of research called Quantum Information Processing (QIP) has rapidly seen interesting theoretical developments: it was in particular shown that using superposition of states leads to computers that could outperform classical ones. The experimental side of QIP however lags far behind as it requires an unprecedented amount of control and understanding of quantum systems. Much effort is spent on finding which particular systems would provide the best physical implementation of QIP concepts. Because of their nearly endless versatility and the high degree of control over their synthesis, organic materials deserve to be assessed as a possible route to quantum computers. This thesis studies the QIP potential of spin degrees of freedom in several such organic compounds. Firstly, a study on low-spin antiferromagnetic rings is presented. It is shown that in this class of molecular nanomagnets the relaxation times are much longer than previously expected and are in particular long enough for up to a few hundred quantum operations to be performed. A detailed study of the relaxation mechanisms is presented and, with it, routes to increasing the phase coherence time further by choosing the suitable temperature, isotopic and chemical substitution or solvent. A study of higher-spin systems is also presented and it is shown that the relaxation mechanisms are essentially the same as in low-spin compounds. The route to multi-qubit system is also investigated: the magnetic properties of several supermolecular assemblies, in particular dimers, are investigated. Coupling between neighbouring nanomagnets is demonstrated and experimental issues are raised concerning the study of the coherent dynamics of dimers. Finally a study of the purely organic compound phenanthrene is reported. In this molecule the magnetic moment does not result from the interactions between several transition metal ions as in molecular nanomagnets but from the photoexcitation of an otherwise diamagnetic molecule. The interest of such a system in terms of QIP is presented and relaxation times and coupling to relevant nuclei are identified.
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Shukla, Nitin. "Heat Transport across Dissimilar Materials." Diss., Virginia Tech, 2009. http://hdl.handle.net/10919/27820.
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All interfaces offer resistance to heat transport. As the size of a device or structure approaches nanometer lengthscales, the contribution of the interface thermal resistance often becomes comparable to the intrinsic thermal resistance offered by the device or structure itself. In many microelectronic devices, heat has to transfer across a metal-nonmetal interface, and a better understanding about the origins of this interface thermal conductance (inverse of the interface thermal resistance) is critical in improving the performance of these devices. In this dissertation, heat transport across different metal-nonmetal interfaces are investigated with the primary goal of gaining qualitative and quantitative insight into the heat transport mechanisms across such interfaces. A time-domain thermoreflectance (TDTR) system is used to measure the thermal properties at the nanoscale. TDTR is an optical pump-probe technique, and it is capable of measuring thermal conductivity, k, and interface thermal conductance, G, simultaneously.
The first study examines k and G for amorphous and crystalline Zr47Cu31Al13Ni9 metallic alloys that are in contact with poly-crystalline Y2O3. The motivation behind this study is to determine the relative importance of energy coupling mechanisms such as electron-phonon or phonon-phonon coupling across the interface by changing the material structure (from amorphous to crystalline), but not the composition. From the TDTR measurements k=4.5 W m-1 K-1 for the amorphous metallic glass of Zr47Cu31Al13Ni9, and k=5.0 W m-1 K-1 for the crystalline Zr47Cu31Al13Ni9. TDTR also gives G=23 MW m-2 K-1 for the metallic glass/Y2O3 interface and G=26 MW m-2 K-1 for the interface between the crystalline Zr47Cu31Al13Ni9 and Y2O3. The thermal conductivity of the poly-crystalline Y2O3 layer is found to be k=5.0 W m-1 K-1. Despite the small difference between k and G for the two alloys, the results are repeatable and they indicate that the structure of the alloy plays a role in the electron-phonon coupling and interface conductance.
The second experimental study examines the effect of nickel nanoparticle size on the thermal transport in multilayer nanocomposites. These nanocomposites consist of five alternating layers of nickel nanoparticles and yttria stabilized zirconia (YSZ) spacer layers that are grown with pulsed laser deposition. Using TDTR, thermal conductivities of k=1.8, 2.4, 2.3, and 3.0 W m-1 K-1 are found for nanocomposites with nickel nanoparticle diameters of 7, 21, 24, and 38 nm, respectively, and k=2.5 W m-1 K-1 for a single 80 nm thick layer of YSZ. The results indicate that the overall thermal conductivity of these nanocomposites is strongly influenced by the Ni nanoparticle size and the interface thermal conductance between the Ni particles and the YSZ matrix. An effective medium theory is used to estimate the lower limits for the interface thermal conductance between the nickel nanoparticles and the YSZ matrix (G>170 MW m-2 K-1), and the nickel nanoparticle thermal conductivity.Ph. D.
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Song, Qiong. "FAST RESPONSE DUAL FREQUENCY LIQUID CRYSTAL MATERIALS." Doctoral diss., University of Central Florida, 2010. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3112.
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Dual frequency liquid crystal (DFLC) exhibits a positive dielectric anisotropy at low frequencies and negative dielectric anisotropy at high frequencies. The frequency where dielectric anisotropy is zero is called crossover frequency. DFLC can achieve fast rise time and fast decay time with the assistance of applied voltage. However, one drawback of DFLC is that it has dielectric heating effect when driven at a high frequency. Thus, the first part of this dissertation is to develop low crossover frequency DFLC materials. The dielectric relaxation and physical properties of some single- and double-ester compounds were investigated. Experimental results indicate that the double-ester compound exhibits a ~ 3 X lower dielectric relaxation frequencies and larger dielectric anisotropy than the single ester, but its viscosity is also higher. More generally, ten groups of dual frequency liquid crystals were compared in terms of dielectric relaxation frequency and dielectric anisotropy. The dielectric relaxation theory was discussed at last. To realize fast response time, high birefringence and low viscosity LC are required. From these two aspects, firstly four new high birefringence laterally difluoro phenyl tolane liquid crystals with a negative dielectric anisotropy were studied. These materials are used to enhance the birefringence of DFLC. They have a fairly small heat fusion enthalpy (~3000 cal/mol) which improves their solubility in a host. We dope 10 wt% of each compound into a commercial negative mixture N1 and measured their birefringence, viscoelastic constant and figure of merit. Birefringence varies very little among homologues while viscoelastic constant increases as alkyl chain length increases. Secondly, we studied the effects of six diluters for lowering the viscosity while stabilizing the vertical alignment (VA) of the laterally difluoro terphenyl host mixture at elevated temperatures. The pros and cons of each diluter are analyzed. These lateral difluoro terphenyls exhibit a high birefringence, fairly low viscosity, and modest dielectric anisotropy, but their molecular alignment in a VA cell is gradually deteriorated at elevated temperatures as their concentration increases. As a result, the device contrast ratio is decreased noticeably due to the light leakage through the crossed polarizers. Finally, liquid crystal doped with metallic nanoparticles, such as Pd, Ag, or Ag-Pd, which are protected with ligand molecules, such as nematic liquid crystal were studied. The metal nanoparticles doped LC exhibit a frequency modulation (FM) electro-optical (EO) response in the millisecond to submillisecond range together with the ordinary root-mean-square voltage response.Ph.D.
Optics and Photonics
Optics and Photonics
Optics PhD
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Hilker, Jesse Kirtland. "On Building: A Return of the Master Builder." Thesis, Virginia Tech, 2019. http://hdl.handle.net/10919/91394.
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This project aims to chronicle the process of building from the architects point of view. Not mindless, mechanical tasks aimed at some economic goal; but tangible, thoughtful work towards an educational and philosophical desire. The desire to be a Master-Builder has fueled architects for centuries. It is a role that the common definition of Architect has all but forgotten. While in practice very few of us will continue this tradition, it is important that we not lose this fundamental aspect of building.
To begin to fulfill oneself with this title, the path is very simple: build a building. That is what follows in this book. It is a chronological outline of the design and build of the New River Valley Train Observation Tower. An additional layer to this project is the inclusion of a variety of innovative building materials/techniques, particularity the use of hardwood cross-laminated timber (CLT). This building will serve as an ongoing research opportunity to evaluate the conditions of building with this material in an extreme condition, complete exposure to weather.
No work of architecture is a solo endeavor, yet my heavy involvement in the design, documentation, and building of the tower has culminated in a body of work that is distinctly my own. My role was that of a project manager, and I reported to faculty Kay Edge, Edward Becker, and Robert Riggs. This structure allowed me to have a great deal of independence, while vetting my drawings and ideas with experienced professionals. A small group of students joined me in the larger aspects of the build, which provided another opportunity to discover an aspect so critical to building: collaboration. This build taught so much about project management, design, and realization that could only be understood through such a physical experience.Master of Architecture
This project aims to chronicle the process of building from the architects point of view. Not mindless, mechanical tasks aimed at some economic goal; but tangible, thoughtful work towards an educational and philosophical desire. The desire to be a Master-Builder has fueled architects for centuries. It is a role that the common definition of Architect has all but forgotten. While in practice very few of us will continue this tradition, it is important that we not lose this fundamental aspect of building. To begin to fulfill oneself with this title, the path is very simple: build a building. That is what follows in this book. It is a chronological outline of the design and build of the New River Valley Train Observation Tower. An additional layer to this project is the inclusion of a variety of innovative building materials/techniques, particularity the use of hardwood cross-laminated timber (CLT). This building will serve as an ongoing research opportunity to evaluate the conditions of building with this material in an extreme condition, complete exposure to weather. No work of architecture is a solo endeavor, yet my heavy involvement in the design, documentation, and building of the tower has culminated in a body of work that is distinctly my own. My role was that of a project manager, and I reported to faculty Kay Edge, Edward Becker, and Robert Riggs. This structure allowed me to have a great deal of independence, while vetting my drawings and ideas with experienced professionals. A small group of students joined me in the larger aspects of the build, which provided another opportunity to discover an aspect so critical to building: collaboration. This build taught so much about project management, design, and realization that could only be understood through such a physical experience.
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Rothschedl, Christopher, Roland Ritt, Paul O'Leary, Matthew Harker, Michael Habacher, and Michael Brandner. "Real-time-data analytics in raw materials handling." Technische Universitaet Bergakademie Freiberg Universitaetsbibliothek "Georgius Agricola", 2018. http://nbn-resolving.de/urn:nbn:de:bsz:105-qucosa-231350.
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This paper proposes a system for the ingestion and analysis of real-time sensor and actor data of bulk materials handling plants and machinery. It references issues that concern mining sensor data in cyber physical systems (CPS) as addressed in O’Leary et al. [2015].
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Spencer, Ben. "Pump-probe spectroscopy of photovoltaic materials." Thesis, University of Manchester, 2011. https://www.research.manchester.ac.uk/portal/en/theses/pumpprobe-spectroscopy-of-photovoltaic-materials(f4b7f755-338a-4fad-814c-4dcc95d5b72d).html.
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The study of photovoltaic materials is important so as to develop new solar energy technologies: in particular, quantum-confined semiconductors could offer increased quantum efficiencies at a much lower manufacture cost. This thesis contains results from a number of pump-probe experiments designed to probe the carrier dynamics in bulk and quantum-confined photovoltaics. A THz time-domain spectrometer was designed, built and commissioned. The THz refractive indices and absorption coefficients of toluene and hexane were determined, and the spectrometer was benchmarked using a photoexcited GaAs wafer. Results are presented of time-resolved THz spectroscopy of photoexcited bulk InP as a function of laser excitation wavelength. These data were used to extract the quantum efficiency of bulk InP in order to compare with recent results for InP quantum dots. The quantum efficiency in quantum dots increases when the incident photon energy is at least twice the band gap energy, whereasthe efficiency of the bulk material is found to decrease. This is because of surface recombination, and these measurements therefore verify the potential superiority of quantum dot materials over bulk materials for use in solar energy applications. Initial measurements of quantum dots using THz spectroscopy highlighted the various experimental challenges involved and the upgrades required to study such samples in the future.The time-dependence of the photoinduced surface photovoltage (SPV) in Si was studied on nanosecond timescales by synchronizing an ultrafast laser system to a synchrotron radiation source (the SRS at Daresbury, UK), and measuring the resulting shift in the photoelectron spectrum. The equilibrium band bending was determined, and the decay of the SPV was attributed to the recombination of charge carriers across the band gap. Results are presented for the SPV in bulk ZnO and for PbS quantum dot chemically attached to ZnO. The fact that the PbS quantum dots were chemically attached to the surface without becoming oxidized was verified using X-ray photoelectron spectroscopy (XPS). The changes caused by photoexcitation occur on much longer timescales in ZnO than Si (sub-milliseconds rather than nanoseconds), and these timescales were conveniently accessed using the time-resolved XPS facility at the TEMPO beamline at Synchrotron SOLEIL (Paris, France). This is due to oxygen adsorption and desorption processes at the ZnO surface affectingthe transfer of charge carriers. The addition of PbS quantum dots to the ZnO surface was found to increase the speed of this charge transfer due to injection of carriers directly from the PbS quantum dot to the bulk ZnO conduction band.
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Colbert, Mark. "APPEARANCE-DRIVEN MATERIAL DESIGN." Doctoral diss., University of Central Florida, 2008. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/2608.
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In the computer graphics production environment, artists often must tweak specific lighting and material parameters to match a mind's eye vision of the appearance of a 3D scene. However, the interaction between a material and a lighting environment is often too complex to cognitively predict without visualization. Therefore, artists operate in a design cycle, where they tweak the parameters, wait for a visualization, and repeat, seeking to obtain a desired look. We propose the use of appearance-driven material design. Here, artists directly design the appearance of reflected light for a specific view, surface point, and time. In this thesis, we discuss several methods for appearance-driven design with homogeneous materials, spatially-varying materials, and appearance-matching materials, where each uses a unique modeling and optimization paradigm. Moreover, we present a novel treatment of the illumination integral using sampling theory that can utilize the computational power of the graphics processing unit (GPU) to provide real-time visualization of the appearance of various materials illuminated by complex environment lighting. As a system, the modeling, optimization and rendering steps all operate on arbitrary geometry and in detailed lighting environments, while still providing instant feedback to the designer. Thus, our approach allows materials to play an active role in the process of set design and story-telling, a capability that was, until now, difficult to achieve due to the unavailability of interactive tools appropriate for artists.Ph.D.
School of Electrical Engineering and Computer Science
Engineering and Computer Science
Computer Science PhD
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Rothschedl, Christopher, Roland Ritt, Paul O'Leary, Matthew Harker, Michael Habacher, and Michael Brandner. "Real-time-data analytics in raw materials handling." TU Bergakademie Freiberg, 2017. https://tubaf.qucosa.de/id/qucosa%3A23195.
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This paper proposes a system for the ingestion and analysis of real-time sensor and actor data of bulk materials handling plants and machinery. It references issues that concern mining sensor data in cyber physical systems (CPS) as addressed in O’Leary et al. [2015].
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Venkatapathi, Sarankumar. "Temperature effects on the electronic properties of lead telluride (PbTe) and the influence of nano-size precipitates on the performance of thermoelectric materials. (SrTe precipitates in PbTe bulk material)." Thesis, Virginia Tech, 2013. http://hdl.handle.net/10919/51947.
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This study seeks to evaluate the temperature effects on the electronic properties of thermoelectric materials, using first principles Density Functional Theory (DFT) calculations by incorporating the temperature effects on structural properties of the material. Using the electronic properties attained, the charge carrier scattering relaxation times were determined. The effect of interface between PbTe and SrTe on the charge carrier mobility was studied by finding out the relative alignment of energy bands at the semiconductor heterojunction. The crystal shape of the SrTe precipitates in the PbTe host matrix was evaluated from the interface energies using the Wulffman construction. We also attempted to develop a relation between the interface energies and electronic band alignment for different interface orientations.
In this research, we incorporated the temperature effects on the structural properties of PbTe to get the temperature dependence of electronic properties like energy bandgap and effective masses of charge carriers. We used the values of bandgap and effective masses to determine the charge carrier scattering relaxation time at different temperatures which is used in evaluating the transport properties of thermoelectric materials like the Seebeck coefficient and electrical conductivity.Master of Science
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Penedo, Cátia Maria Lourenço. "A organização do espaço, do tempo, dos materiais e do brincar na creche e no jardim – de – infância." Master's thesis, Instituto Politécnico de Setúbal. Escola Superior de Educação, 2017. http://hdl.handle.net/10400.26/19646.
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Relatório de Projeto de Investigação
Mestrado em Educação Pré-EscolarO presente projeto de investigação tem como temática central a organização do espaço, dos materiais e do tempo na Creche e no Jardim – de – Infância. A presente investigação teve como ponto de partida as vivências experienciadas, em quatro momentos, em duas instituições distintas em contexto de Creche e Jardim – de – Infância, onde tive oportunidade de estagiar no âmbito do Mestrado em Educação Pré-Escolar. Este estudo teve como objetivo compreender como otimizar a organização do espaço, dos materiais e do tempo educativo, compreender e interpretar as conceções e o sentido pedagógico que as equipas atribuem à organização do espaço, dos materiais e do tempo, enquanto recursos educativos. Ao mesmo tempo, este estudo teve também como intencionalidade, intervir de modo a melhorar os espaços das instituições onde estagiei, de forma a criar novos desafios e experiências que contribuíssem para a aprendizagem e desenvolvimento das crianças. O projeto desenvolvido adota o paradigma interpretativo da investigação qualitativa, particularizando-se na abordagem da investigação – ação.
This research project has as its central theme the Organization of space, materials and time in the nursery and kindergarten. The investigation took as its starting point the experiences experienced in four times, in two distinct institutions in context of Nursery and kindergarten, where I had the opportunity to intern for master degree in pre-school education – schools. This study aimed to understand how to optimize the Organization of space, materials and educational time, understand and interpret the concessions and the pedagogical sense that teams attach to the Organization of space, time and materials, while educational resources. At the same time, this study had also as intentionality, intervene in order to improve the spaces of the institutions where I worked, in order to create new challenges and experiences that contribute to the learning and development of children. The project developed adopts interpretive paradigm of qualitative research, more specifically on research-action approach.
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Cruz, Maria (Maria Regina Torres). "The impact of plant product harvesting on Derre Miombo woodlands, Mozambique / by Maria Cruz." Thesis, Stellenbosch : Stellenbosch University, 2002. http://hdl.handle.net/10019.1/53124.
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Thesis (MScFor)--Stellenbosch University, 2002.ENGLISH ABSTRACT: This study investigates how information on plant products can be used to incorporate local users into joint forest management planning by developing guidelines for sustainable collaborative management in Derre miombo woodland in the Zambézia Province in Mozambique. From the participatory appraisal, it was found that 46 woody miombo species were used in the five villages for at least 29 different purposes. Five of these species (Brachystegia boehmii, B. spiciformis, Pterocarpus angolensis, Terminalia sericea and Swartzia madagascariensis) were selected for analysis because of their multiple uses and the unknown impact of their harvesting on the future survival of those hardwood trees species. In order to determine the impact of human resource extraction on the forest and on the dynamics of tree canopy populations an inventory of woody plants was.carried out for two categories of forest land-use, namely selective harvesting and fallow land (approximately 15 years old). This was done for Golombe and Arame villages and for selective harvesting only for Mphoto village, on 23, I-ha random selected plots in the woodland adjacent to the three villages. The population structure of the five species T sericea, S. madagascariensis, P. angolensis, B. boehmii and B. spiciformis showed different trends in each of the three villages. Size class distribution of the first tree species gave evidence that the species were being harvested for building poles. This study has shown that, through plant species products, miombo contribute to the livelihoods of the local communities living in Derre woodlands. In this study it was found that usually more than one species were used for one product as well as most of the species being trees with multiple uses. This study has also provided some evidence that P. angolensis and S. madagascariensis can benefit from shifting cultivation and fire, which encourages coppice regeneration. More research is required to further validate this evidence.
AFRIKAANSE OPSOMMING: Hierdie studie ondersoek die moontlikhede wat inligting oor spesifieke plantprodukte bied, in die betrekking van plaaslike gemeenskappe in die proses van gesamentlike bosbestuurs- en beplanningspraktyke. Verder word riglyne opgestel aangaande die volhoubaarheid van die gesamentlike bestuurs- en beplanningspraktyke in die Derre miombo bosveld, in die Zambézia Provinsie in Mozambique. Inligting verkry vanuit die deelnemende opname dui aan dat in die vyf nedersettings wat ondersoek is, 46 houtagtige miombo spesies vir ten minste 29 verskillende doeleindes aangewend word. Vyf van die spesies (Brachystegia boehmii, B. spiciformis, Pterocarpus angolensis, Terminalia sericea en Swartzia madagascariensis) is geselekteer vir gebruik in analises as gevolg van hul benutbaarheid deur plaaslike inwoners en die feit dat minimale inligting beskikbaar is oor die impak van gebruik van die harde hout spesies op hul volhoubare benutting en voortbestaan. 'n Opname van houtagtige spesies is uitgevoer in areas wat val in een van twee bosgrondgebruiks kategoriee nl. areas wat selektief geoes en benut word, en braaklande (ongeveer 15 jaar oud). Dit is gedoen om die impak wat verwydering van boshulpbronne deur mense op die boomkruin populasies het, vas te stel. Die opname strategie is gevolg in 23 ha persele, uitgelê in die gebiede wat die Golombe, Arame en Mphoto nedersettings omring - in die geval van laasgenoemde nedersetting is slegs die impak van selektiewe benutting ondersoek. Die populasie struktuur van die vyf studiespesies (T sericea, S. madagascariensis, P. angolensis, B. boehmii en B. spiciformis) het verkil vir elk van die drie nedersettings wat ondersoek is. Die verspreiding van grootte klasse vir die eerste spesie, het aangedui dat die spesie vir gebruik as konstruksie pale geoes word. Die miombo bosveld plantegroei-tipe dra by tot die lewensonderhoud van plaaslike gemeenskappe in die vorm van plant produkte, in die Derre omgewing. Daar is verder gevind dat meer as een spesie dikwels vir dieselfde doel aangewend kan word en die meeste van die spesies wat benut word is boomagtig met meer as een gebruik. In die studie is verder aanduidings gevind dat P. angolensis en S. madagascariensis kan baatvind by grondverbouings praktyke wat gereeld verskuif word en ook brande, omdat beide praktyke kreupelhout regenerasie stimuleer. Verdere navorsing word egter benodig om dié bevinding te ondersteun.
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Frisk, Carlman Joel. "Äventyrstorn : En undersökning av konstruktionslösningar och material." Thesis, Mittuniversitetet, Avdelningen för ekoteknik och hållbart byggande, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-35529.
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Deep Wild är ett företag som bland annat specialiserar sig på produktutveckling och byggande av äventyrsanläggningar. Kunder till företaget har efterfrågat ett typ av äventyrstorn som det är möjligt att åka zipline från samt utföra andra aktiviteter såsom klättring på. Då Deep Wild inte har egen kompetens gällande dimensionering och projektering av denna typ av torn har en förfrågan skickats ut till studenter för att se om det fanns intresse att ta fram en lösning på utförandet. Syftet med arbetet är att undersöka hur ett äventyrstorn som detta kan konstrueras och ta fram en lösning på utförandet. Tornet dimensioneras enligt gällande Eurokoder. De laster som genereras av specialutrustningen tornet förses med finns i Svensk Standard. Två lösningar på möjliga utföranden tas fram, ett med alla bärande delar i stål och ett med lämpliga bärande delar i trä. Dessa jämförs sedan med hänsyn till lämplighet. Det visar sig att det finns många fördelar med att bygga tornet med enbart stålprofiler. Med stål som material kan alla bärande delar köpas ur det lagerförda sortiment som erbjuds på marknaden. Med trä finns inga lagerförda dimensioner att tillgå för de laster som uppstår. Vid de knutpunkter som dimensionerats visar det sig att de utförda i stål enkelt kan utföras så att de har mycket god säkerhetsmarginal. Knutpunkterna i träkonstruktionen klarar de dimensionerande lasterna endast med små marginaler. Genom att mer specialanpassa utseendet hos konstruktionen och dess verkningssätt så kan möjligtvis utförandet i trä gynnas. En prisjämförelse mellan de två materialen visar att skillnaden i materialpris är försumbar i sammanhanget. Två alternativa stabiliseringssystem undersöks för tornet. Det ena är att staga med en fackverkskonstruktion som använder sig av dragna stålstänger och tryckta strävor av respektive utförandematerial. Det andra är att staga tornet genom skivverkan i klätterväggen som uppförs på tornets ena sida. Skivverkan har sina fördelar då det möjliggör tryckta strävor på olika höjd i tornet. Fackverkskonstruktionen är dock att rekommendera då denna kan dimensioneras att ta avsevärt högre laster. Det naturliga nästa steget i arbetet ligger i att ta fram ett förfrågningsunderlag tillräckligt komplett för att kalkyleras.Deep Wild is an adventure company which specializes in product development among other things. Customers of the company have been asking for a tower from which it’s possible to exercise different kinds of adventure activities, such as ziplining and climbing. Deep Wild doesn’t have in house experience from constructing supporting structures that are not directly related to the special equipment used to exercise these activities. Therefore students have been asked to find a solution on how to construct a tower like this. The purpose of this study is to investigate how an adventure tower can be constructed. The tower is structurally designed using Eurocodes and the loads generated from the activities exercised appear in European Standard. Two possible solutions for the construction is developed, one with all supporting parts in steel and one with selected supporting parts in wood. These are then compared to each other with regard to their performance. The results show that there are many advantages using only steel profiles. All steel profiles required for the construction can be bought out of existing stock from producers. To use wooden profiles it is required to place orders on standard dimensions that are not part of the producers existing stock. The joints designed shows that using steel profiles these can easily be designed to provide a high safety margin. The joints designed using steel connectors to wooden profiles provides enough support only with small safety margins. By adjusting the design of the towers supporting system the use of wooden profiles could possibly be benefitted. A price comparison based on the price of material shows that the difference between laminated timber and steel in this construction is negligible. Two alternative ways of stabilizing the tower have been investigated. One with tensioned steel bracing and compressed bracing using the different construction materials. The other one using wall diaphragms on the side of the tower clad with climbing wall. The wall diaphragms method has its advantages because it makes it possible to place compressed bracings on different heights in the tower. The system with tensioned bracings can take higher loads and provide better safety margins and is therefore the recommended way of stabilizing this tower. The next step of this project is to provide complete enough material to calculate the cost of constructing.
Betyg 2018-06-05