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Experimental characterization of heat transfer from an electrically heated thin filamentCragg, Amy J. January 1999 (has links)
Thesis (M.S.)--West Virginia University, 1999. / Title from document title page. Document formatted into pages; contains xviii, 177 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 140-141).
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Deformation and evolution of morphology in meltblown filamentsDorsey, Kyra 05 1900 (has links)
No description available.
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Mechanics of Nb-Ti superconducting compositesGuo, Zhiqiang 23 June 1994 (has links)
Mechanical behavior of Nb-Ti superconducting composites with copper matrices have
been studied experimentally and theoretically.
Experimental work includes extensive measurements of Cu/Nb-Ti composite system.
Techniques for fine fiber testing and composite wire measurement have been developed.
Experimental parameters examined in this research include geometry, hardness, Young's
modulus, Poisson's ratio, yield strength and ultimate strength. Three theoretical models
have been developed to study the mechanics of the Cu/Nb-Ti composite system. The
influence of several design parameters on the mechanics of the Nb-Ti composites was
studied and provides some insight on superconducting composite design for improvements
in processing and performance.
The mechanical behavior of the Cu/Nb-Ti composite system are found to be functions
of geometry, composition and processing.
Geometry of Nb-Ti superconducting composites is different from most engineering
composites and there are two factors affecting sample geometry: the variability of fiber
geometry and the placement of fibers within the composite. The strength distribution of
Nb-Ti fibers is closely related to the distribution of fiber geometry and the composite
strength increases as the scatter of fiber strength decreases.
Heat treatment reduces the hardness of the bulk copper dramatically. The first heat
treatment increases the strength and hardness of the Nb-Ti fibers, further heat treatments
reduce the strength and hardness while increasing Young's modulus of the fibers. As the
extent of cold work increases, the strength of Nb-Ti fibers and that of the composite wires
increases. Cold work effects on the Young's modulus of the composites and the Nb-Ti
fibers are not significant.
For a constant global Cu/SC ratio, the lower the local Cu/SC ratio, the lower the micro-in-plane stresses. From this point of view, the fibers should be packed as close as possible
to one another. For a constant local Cu/SC ratio, when the inner radius of the Nb-Ti
assembly increases (the fibers are packed further from center), the macro-in-plane stresses
increase. From this point of view, the fibers should be packed as close to the center of the
wire as possible.
For a constant geometry, the higher the difference between E[subscript f] and E[subscript m], the lower the in-plane
stresses, and the higher the difference of the Poisson's ratio between the
components, the higher the in-plane stresses. / Graduation date: 1995
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Prospective structured support and nanostructured active phase for oil upgradingChhabra, Arvind Unknown Date
No description available.
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Structural behaviour of steel fibre reinforced concrete membersAoude, Hassan. January 1900 (has links)
Thesis (Ph.D.). / Written for the Dept. of Civil Engineering and Applied Mechanics. Title from title page of PDF (viewed 2008/05/08). Includes bibliographical references.
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Seismic behaviour of beam-column joint subassemblies reinforced with steel fibres : a thesis submitted in partial fulfilment of the requirements for the degree of Master of Engineering at the University of Canterbury, Christchurch, New Zealand /Liu, Cong. January 1900 (has links)
Thesis (M.E.)--University of Canterbury, 2006. / Typescript (photocopy). "January 2006." Includes bibliographical references (p. 177-184). Also available via the World Wide Web.
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Experimental investigation on behavior of steel fiber reinforced concrete (SFRC) : a dissertation submitted to the University of Canterbury in partial fulfillment of the requirements for the degree of Master [of Engineering] /Wang, Chuanbo. January 1900 (has links)
Thesis (M.E.)--University of Canterbury, 2006. / Typescript (photocopy). "August 2006." Includes bibliographical references. Also available via the World Wide Web.
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Influence of steel fibres on response of beamsBelghiti, Moulay El Mehdi. January 2007 (has links)
The following thesis presents the results of six full scale beams tests as part of a research program conducted at McGill University on the effect of steel fibres on the shear capacity of a beam with an aid ratio greater than 2.5. The test specimens had the following dimensions: 4400 mm long, 300 mm wide and 500 mm long. The beams had 4-25M bottom reinforcing bars and 2-20M top reinforcing bars. Two series were designed with different reinforcing details: the "BA" series contained transverse reinforcement spaced at 275 mm center to center while the "BB" series had no transverse reinforcement. The specimens were cast in three batches of two specimens from each series, with each batch containing concrete with respectively 0%, 0.5% and 1% fibres content by volume. The beams were simply supported and were tested with two equal point loads located at 500 mm from the centre of the beam. / This research project demonstrated a clear improvement of the shear capacity resulting from the use of steel fibres for the beams without transverse reinforcement. For the beams with transverse reinforcement, displacement ductility was highly increased. This suggests that fibres have the potential to reduce the congestion of the reinforcement if fibres are designed to replace partially closely spaced transverse reinforcement. Also, it was noted that a redistribution of stresses occurred resulting in the formation of more well-controlled cracks. Finally, the strength predictions using the method developed by Aoude (Aoude, 2007) agree very well with the experimental results.
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Avaliação de propriedades mecânicas de porcelanato reforçado com fios metálicosGarbelotto, Roslene de Almeida January 2013 (has links)
Neste trabalho foi avaliado o desempenho mecânico de um compósito formado por massa cerâmica de porcelanato sendo a matriz e fios de aço o reforço, visando a utilização como cerâmica de revestimento. Com a inserção do fio metálico, teve-se por objetivo aumentar a tenacidade elevando a resistência mecânica ao impacto, proporcionando maior segurança em caso de ruptura acidental. O estudo laboratorial avaliou o comportamento mecânico de corpos de prova sem fios e com a adição de fios. Os fios foram distribuídos longitudinalmente em três configurações. Os corpos possuíam 1600 mm2 de superfície e receberam os fios distribuídos em uma, duas e três camadas perfazendo comprimento respectivamente de 325 mm, 650 mm e 975 mm. Foram realizadas as caracterizações padrões para a cerâmica, expansão após prensagem, retração de secagem, densidade a seco, retração de queima, absorção de água e resistência mecânica à flexão. E adicionalmente foram avaliados: resistência mecânica ao impacto, índice de deformação piroplástica, resistência mecânica à tração e análise da microestrutura. O compósito proporcionou redução de aproximadamente 61% na deformação piroplástica e um acréscimo de aproximadamente de oito vezes na resistência ao impacto. Na análise do compósito, a tensão no fio ficou constante em torno de 800 MPa, mantendo aproximadamente 35% ao seu valor ao natural que era de 2000 MPa. O fio teve grandes perdas em suas características individuais, no entanto sua aplicação na cerâmica em forma de reforço do compósito enriqueceu as propriedades do porcelanato o que proporciona oportunidade de novas aplicações. / This study evaluated the mechanical performance of a composite ceramic body of porcelain with a matrix of steel fibers, for use as a ceramic coating. With the insertion of metallic fiber account was intended to increase the toughness for increasing the mechanical impact resistance, providing greater safety in case of accidental rupture. The study assessed the mechanical behavior of the specimen without fibers and with the addition of fiber. The fibers were distributed longitudinally in three configurations. The bodies had 1600 mm2 and received fibers distributed in one, two or three layers with total length of 325 mm, 650 mm and 975 mm respectively. Characterizations patterns for ceramic, expansion after pressing, drying shrinkage, dry apparent density, firing shrinkage, water absorption and mechanical flexural strength were performed. And we’ve checked also: mechanical impact, index pyroplastic deformation, mechanical tensile strength and microstructural analysis. We found that the composite material gave approximately 61% reduction in pyroplastic deformation and an increase of approximately eight times the impact resistance. In the analysis of the composite stress in the fiber was constant around 800 MPa, holding approximately 35 % of their value to the natural which was 2000 MPa. The fiber had big losses on their individual characteristics, however its application in ceramic composite as increased porcelain ceramic properties which provides opportunity for new applications.
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Avaliação de propriedades mecânicas de porcelanato reforçado com fios metálicosGarbelotto, Roslene de Almeida January 2013 (has links)
Neste trabalho foi avaliado o desempenho mecânico de um compósito formado por massa cerâmica de porcelanato sendo a matriz e fios de aço o reforço, visando a utilização como cerâmica de revestimento. Com a inserção do fio metálico, teve-se por objetivo aumentar a tenacidade elevando a resistência mecânica ao impacto, proporcionando maior segurança em caso de ruptura acidental. O estudo laboratorial avaliou o comportamento mecânico de corpos de prova sem fios e com a adição de fios. Os fios foram distribuídos longitudinalmente em três configurações. Os corpos possuíam 1600 mm2 de superfície e receberam os fios distribuídos em uma, duas e três camadas perfazendo comprimento respectivamente de 325 mm, 650 mm e 975 mm. Foram realizadas as caracterizações padrões para a cerâmica, expansão após prensagem, retração de secagem, densidade a seco, retração de queima, absorção de água e resistência mecânica à flexão. E adicionalmente foram avaliados: resistência mecânica ao impacto, índice de deformação piroplástica, resistência mecânica à tração e análise da microestrutura. O compósito proporcionou redução de aproximadamente 61% na deformação piroplástica e um acréscimo de aproximadamente de oito vezes na resistência ao impacto. Na análise do compósito, a tensão no fio ficou constante em torno de 800 MPa, mantendo aproximadamente 35% ao seu valor ao natural que era de 2000 MPa. O fio teve grandes perdas em suas características individuais, no entanto sua aplicação na cerâmica em forma de reforço do compósito enriqueceu as propriedades do porcelanato o que proporciona oportunidade de novas aplicações. / This study evaluated the mechanical performance of a composite ceramic body of porcelain with a matrix of steel fibers, for use as a ceramic coating. With the insertion of metallic fiber account was intended to increase the toughness for increasing the mechanical impact resistance, providing greater safety in case of accidental rupture. The study assessed the mechanical behavior of the specimen without fibers and with the addition of fiber. The fibers were distributed longitudinally in three configurations. The bodies had 1600 mm2 and received fibers distributed in one, two or three layers with total length of 325 mm, 650 mm and 975 mm respectively. Characterizations patterns for ceramic, expansion after pressing, drying shrinkage, dry apparent density, firing shrinkage, water absorption and mechanical flexural strength were performed. And we’ve checked also: mechanical impact, index pyroplastic deformation, mechanical tensile strength and microstructural analysis. We found that the composite material gave approximately 61% reduction in pyroplastic deformation and an increase of approximately eight times the impact resistance. In the analysis of the composite stress in the fiber was constant around 800 MPa, holding approximately 35 % of their value to the natural which was 2000 MPa. The fiber had big losses on their individual characteristics, however its application in ceramic composite as increased porcelain ceramic properties which provides opportunity for new applications.
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