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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Tensile, moment, and torsional resistance evaluation and prediction of mortise-and-tenon joints in wood-based composites

Tu, Can 07 August 2010 (has links) (PDF)
This study was performed to characterize and understand static loading capacities of the T-shaped, end-toace, mortise-and-tenon joints in pine plywood and oriented strandboard (OSB), and to develop mechanical models to predict its tensile, moment, and torsional resistance capacities. Results of the study indicated that the tensile resistance of a stapled-and-glued mortise-and-tenon joint in pine plywood and OSB ranges from 505 to 1933 lb. and 306 to 845 lb., respectively; the moment resistance ranges from 780 to 4428 lb.-in. and 612 to 2309 lb.-in., respectively; and the torsional resistance ranges from 598 to 2292 lb.-in. and 439 to 1260 lb.-in., respectively. The mechanical models proposed in this study were experimentally validated. The tensile, moment, and torsional resistances of a T-shaped, end-toace, stapled-and-glued, mortise-and-tenon joints can be estimated based on knowing basic material properties of single-staple tensile, lateral shear resistance, and material end-toace glue bonding tensile strength and shear strength.
2

The Cairo Dahshur boats

Creasman, Pearce Paul 25 April 2007 (has links)
Excavations conducted in A.D. 1894 and 1895 by French archaeologist Jean- Jacques de Morgan at the funerary complex of the ancient Egyptian Middle Kingdom pharaoh Senwosret III on the plain of Dahshur revealed some unparalleled finds which included five or six small boats. These boats provide a unique opportunity in nautical archaeology—to study contemporaneous hulls. Today, only four of the "Dahshur boats" can be located with certainty; two are in the United States, one in the Carnegie Museum of Natural History in Pittsburgh and one in the Field Museum of Natural History in Chicago. The remaining two are on display in The Egyptian Museum, Cairo. Since their excavation these boats remained relatively inconspicuous until the mid-1980s when a study of the two hulls in the United States was conducted. However, the two boats in Cairo remained largely unpublished. This thesis combines personal observation and recording of the Cairo boats over two summers to reveal more unique characteristics of the hulls and will facilitate a future study of the group as a whole. Each boat is discussed individually and is further divided into its major components by order of construction.
3

The Cairo Dahshur boats

Creasman, Pearce Paul, January 1900 (has links)
Thesis (M. A.)--Texas A&M University, 2005. / "Major Subject: Anthropology" Title from author supplied metadata (automated record created on Apr. 27, 2007.) Vita. Abstract. Includes bibliographical references.
4

Lateral Strength and Ductile Behavior of a Mortise-Tenon Connected Timber Frame

Kouromenos, Alexandros 01 March 2017 (has links)
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.
5

Investigation of Through-Tenon Keys on the Tensile Strength of Mortise and Tenon Joints

Shields, Lance David 19 August 2011 (has links)
A timber frame is a structural building system composed of heavy timber members connected using carpentry-style joinery that may include metal fasteners. A common variant of mortise-and-tenon joints are keyed (or wedged) through-tenon joints. No research on the behavior of wedged joints in timber frames is available. This research provides design knowledge of keyed through-tenon joints from experimental observations and comparisons between mathematical models and experimental measurement. Evaluation of through-tenon keyed mortise and tenon joints was performed by measuring tensile load and stiffness of white oak (Quercus alba) and Douglas-fir (Pseudotsuga menziesii) joints with four- and 11-inch tenons with one and two keys and comparing these results to mathematical models developed from the National Design Specification of Wood Construction (NDS), General Dowel Equations for Calculating Lateral Connection Values (TR-12), and engineering mechanics. Variables included joint species (white oak or Douglas-fir), protruding tenon length (four or 11 inches), and number of keys (one or two). Joints were tested to ultimate load, then model input specimens were cut from tested joints and additional key stock to generate inputs for joint load predictions that were compared to experimental joint load results for validation. Forty joints were tested with white oak keys and six of these joints were retested with ipe (Tabebuia) keys. Joints with four-inch tenons behaved in a brittle manner with tenon failures. Most joints with 11-inch tenons behaved in a ductile manner with key bending and crushing failures. Joint load and stiffness was similar between white oak and Douglas-fir joints. Joints with 11-inch tenons had greater load and stiffness than with four-inch tenons. Joints with two keys had greater load and stiffness than joints with one key, after normalizing joint load and stiffness responses on key width. Joints retested with ipe keys had greater load than joints originally tested with white oak keys. Tenon relish (row tear-out) failure was predicted for all joints with four-inch tenons. Horizontal key shearing was predicted for all joints with 11-inch tenons. Ratios of predicted ultimate joint load divided by experimental ultimate joints load (calculated/tested) or C/T ratios were used to validate the models chosen for load prediction. C/T ratios showed that ultimate load model predictions over predicted joint load which was due to occurrence of unpredicted tenon failures and simultaneously occurring key failures where models predicted key failures independently. Design safety factors (DSFs) were developed by dividing experimental ultimate joint load by governing allowable (design) load predictions. C/T ratios and DSFs were most similar between white oak and Douglas-fir joints and most different between joints with one and two keys. Alternative design values (ADVs) were developed for comparison to design load predictions. Comparisons between ADVs and DSFs showed that model predictions were most conservative for joints fastened with denser keys than joint members. / Master of Science
6

Stark, starkare, starkast : en jämförelse av fasta tappar och centrumtappar med utgångspunkt i tappens dimensioner, inpassning, komprimering, antal och limning / Optimizing the stability : an investigation of tenon and dowel joints regarding their dimensions, fitting, compression, number and glueing

Berglund, Jonas January 2018 (has links)
I mitt examensarbete jämför jag styrkan för sammanfogningar i trämöbler med fasta tappar och centrumtappar utifrån fem parametrar: tappens dimensioner, tappens inpassning, tappens komprimering, tappens antal och tappens limning. Den övergripande frågan har varit, ”är fasta tappar eller centrumtappar starkast?” Målet har varit att sålla i olika teorier rörande dessa två typer av sammanfogningar och skapa ett underlag i syfte att hjälpa möbelsnickare och formgivare att kunna ta medvetna beslut vad gäller sina val av dessa typer av sammanfogningar. Genom litteraturstudier och verkstads besök har jag samlat kunskap som ligger till grund för det hållfasthets test jag sedan gjort i materiallabbet på Linköpings universitet. Testet har utgått från ett scenario där en stols bakben ska fogas samman med en sarg. Testet visar, utifrån ett antal angivna avgränsningar, att fasta tappar utan undantag är starkare än centrumtappar.Det visar också att en dubbel fast tapp fördelar belastningen bättre än en enkel fast tapp och bidrar till en betydligt starkare fog. För c-tappar gäller generellt att ökat antal tappar ökar fogens seghet men inte nödvändigtvis maxbelastningen. Inpassning och komprimering har betydelse för hur seg en fog är. / I have in my thesis compared the strength of mortise and tenon joints and dowel joints in wooden furniture. I´ve made the comparison based on five parameters: the dimensions of the tenon or dowel, the fit of the tenon or dowel, the compression of the tenon or dowel, the number of tenons or dowels and the gluing of the tenon or dowel. The bigger question has been, “is the mortise and tenon joint or the dowel joint the strongest?” The goal has been to go through different theories regarding these two types of joinery and making a foundation to help cabinet makers and designers to make conscious decisions regarding their choices of these two types of joinery. Through studies of literature and visiting workshops I´ve gathered knowledge that lies as a foundation for a test of strength of different joinery made in the material testing facility of Linköping University. The test was based on a scenario of joining the back leg and side rim of a chair. The test shows, from the given definitions, that mortise and tenon joints are without exceptions stronger than dowel joints. It also shows that double tenons better will distribute the load and make for a stronger and tougher joint. Dowel joints will get tougher with an increased number of dowels but it will not necessarily make for a stronger joint. The fit and compression of the tenon or dowel will affect the joints strength.
7

Mekanisk prestanda hos traditionella träfogar kontra samtida byggbeslag / Mechanical performance of traditional wood joints compared to contemporary steel fasteners

Dahl, Arvid, Lindström, Charlie January 2018 (has links)
Samhället efterfrågar idag i allt högre grad miljövänlig och hållbar byggnation. Ett sätt möta dessa nya krav på miljövänlig byggnation är att använda mer trä då detta minskar koldioxidutsläpp genom substitutionseffekten. Syftet att undersöka huruvida traditionella fogningstekniker som helt utförs i trä kan ersätta samtida fogar i framtida byggnation. Målet är att visa att detta är möjligt ur hållfasthetssynpunkt. Undersökningen kommer att begränsas till att undersöka en pelar-balk-anslutning där den traditionella fogen representeras av tre olika varianter tapp i tapphålsfog och den samtida av balksko. Fogarna undersöks beräkningsmässigt samt genom försök där belastningsfallet ämnar ge en hög tvärkraft. Resultaten pekar på att det är möjligt att introducera den undersökta traditionella träfogningstekniken vid samtida byggnation. / Societies demand for environmentally friendly and sustainable construction is ever increasing. One way to meet these new demands on environmentally friendly construction is to use more wood which decreases carbon emissions through the substitution effect. This report aims to research whether traditional joinery techniques entirely executed in wood can replace contemporary joinery techniques in future construction. The goal is to show whether this is possible from a strength standpoint. The research will be limited in that it will strictly seek to study a pillar-beamconnection where the traditional joint researched will be three varying mortise and tenon joints and the contemporary joint is a joist hanger. The joints will be analyzed with calculation and experimentation where the load case aims to produce mainly shear in the joint. The results point towards it being possible to introduce this traditional joint in contemporary construction.
8

Melkstoeltjies in die versamelings van die Nasionale Kultuurhistoriese Museum: ‘n ondersoek na tipologie (Afrikaans)

Botes, Nico 10 December 2009 (has links)
Milking stools in the collections of the National Cultural History Museum: an investigation of typology. In this study the physical or other characteristics that might typify the traditional milking stool is investigated. This was done by studying a comparable group of eighteen examples from the Anthropology and Cultural History collections of the National Cultural History Museum in Pretoria. Six of the objects in the group studied had already been associated with the Afrikaans catchword ‘melkstoel’, hence the primary sources that informed the research included the museological data from the existing documentation of the Museum. The investigation confirmed that corresponding physical attributes, especially that pertaining to construction, could be identified in the group studied. It was also found that the objects had seen multiple, but indeterminable, functional applications. Since fifteen of the eighteen examples studied were essentially anonymous, as no documented provenance existed, their origin, history and meaning could not be established. The research was therefore extended to secondary sources, being textual descriptions and images, from which associations and correlations between the group studied and milking stools, especially from Western Europe and the English-speaking world, could be affirmed. Moreover, such links were also found to exist with other stools and certain vernacular chair typologies of shared approach, especially as to their construction. Findings identified certain typological features of the milking stool, but also a symbolic and metaphorical association. Multiple functions of and applications for the milking stool could be ascertained. AFRIKAANS : In hierdie studie word ondersoek ingestel of enige eienskappe, fisies of andersins, die tradisionele melkstoeltjie tipeer. Dit is onderneem aan die hand van ‘n studiegroep van agtien soortgelyke voorwerpe uit die Antropologie-versameling en die Kultuurhistoriese versameling van die Nasionale Kultuurhistoriese Museum, Pretoria. Dié primêre bronne word in die ondersoek ondersteun deur museale bronne ontsluit uit die Museum se dokumentasiesentrum, waar ses van die voorwerpe in die studiegroep reeds assosieer is met die trefwoord ‘melkstoel’. Die ondersoek het bevestig dat sekere fisiese kenmerke van die studiegroep, veral in hul konstruksie, dui op groepsverband. Daar is ook bevind dat die voorwerpe vir meervoudige, maar onbepaalde, funksies gebruik is.Van die agtien voorwerpe in die studiegroep is vyftien van anonieme herkoms, sodat hul oorsprong, geskiedenis en betekenis nie met sekerheid vasgestel kon word nie. Die navorsing is daarom uitgebrei na tekstuele beskrywings en beelde, as sekondêre bronne, om hierdie en ander kenmerke te ondersoek. Hieruit is die studiegroep in verband gebring met melkstoeltjies uit veral Wes-Europa en die Engelssprekende wêreld, asook ander stoeltjies en volkstoele wat soortgelyke eienskappe en konstruksiekenmerke het. Bevindings dui op bepaalde tipologiese kenmerke van ‘n melkstoeltjie, maar ook ‘n wyer, assosiatiewe begrip wat manifesteer in beeldspraak en ‘n metaforiese konteks. Meervoudige gebruike en aanwendings van die melkstoeltjie is nagespeur. Copyright / Dissertation (MInt)--University of Pretoria, 2010. / Architecture / unrestricted
9

Gestaltning och dimensionering av metallfria knutpunkter / Design of non-metallic timber connections

Al-saadi, Mohammed, Hilal, Marwa Abdulnasir Hilal January 2020 (has links)
This thesis aims to develop knowledge of non-metallic connections in order to develop and change the Swedish wood architecture as well as wood structures. The main question being "Are metal-free connections suitable for contemporary timber buildings?". In the theory chapter, facts about wood are introduced, followed by literature studies and previous research. Through literature research in the university database and conducting interviews with an architect, a designer and a carpenter, data was collected for the design process and for the calculation of the dimensions for one of the selected glulam connections. The result showed that there is a lack of knowledge in Sweden regarding non-metallic connections, other countries such as Switzerland are more developed in the area and has accepted the idea of this concept. The result also showed that the lack of strength in wooden connections lead to large dimensions of the timber elements, but an aesthetic advantage can be developed. Finally, the results are discussed and analyzed according to the different requirements set on appearance, durability and manufacturability. / Detta examensarbete syftar till att utveckla kunskap om metallfria knutpunkter för att möjliggöra en mer varierad svensk träarkitektur. Den övergripande frågan har varit ”Hur väl lämpar sig metallfria knutpunkter för nutida byggande av träkonstruktioner?”. I teorikapitlet beskrivs fakta om materialet trä, följt av beskrivning av litteratur och tidigare forskning som är relevant för denna studie. Genom en litteraturstudie via universitetets databaser samt intervjuer med en arkitekt, en konstruktör och en möbeldesigner samlades data för gestaltningsprocessen och dimensionering av en knutpunkt i limträ. Resultatet visade att det finns kunskapsbrist i Sverige gällande metallfria knutpunkter, andra länder som Schweiz är mer utvecklade inom området samt har accepterat tanken på detta koncept. Resultatet visade även att frågor kring hållfasthet leder till stora dimensioner för de ingående träelementen, men att en estetisk fördel kan utvecklas. Slutligen diskuteras och analyseras resultaten utefter olika krav som ställts på utseende, hållfasthet och tillverkning.
10

Phoenician ships : types, trends, trade and treacherous trade routes

Smith, Anne Marie (Biblical archaeologist) 11 1900 (has links)
Phoenician ships in the broadest sense of the word are the focus of this dissertation and it encompasses the entire period of both Phoenician and Punic seafaring. The study is quantitative, largely historical and archaeological, with the use of secondary sources as well as iconography. The origins of the Phoenician construction technique, the mortise-and-tenon joints, are investigated as well as the various types of Phoenician ships. These are analysed under the headings Merchant ships, Warships and Utility ships. The materials mentioned in Ezekiel’s prophecy about ‘The Ship Tyre’, are analysed, whether they fit the purpose for which they are mentioned. The production process of purple cloth with the use of Murex molluscs is described in detail including an analysis of the boats used to catch the molluscs. The possibility is investigated of whether the Ashkelon Dog Burials could be related to the Phoenician trade in dogs, and whether they could have served as ship dogs. Lastly the difficulties encountered in sailing through the narrow sea straits of the Mediterranean Sea are described, which are subject to Internal waves, affecting the surface water. / Old Testament & Ancient Near Eastern Studies / M. A. (Biblical Archaeology)

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