Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 19 of 19 for “"Fibrous composites"”.
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Nonlinear analysis of laminated fibrous composites
… analysis of the nonlinear behavior of fibrous composite laminates including axial loading, thermal loading, temperature dependent properties, and edge effects is presented. Ramberg-Osgood approximations are used to represent lamina stress-strain behavior and percent retention curves are …
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Simplified micromechanical models for analysis of interface debonding in a fibrous composite
… the effective transverse elastic modules of fibrous composites with a partial interface crack based on the material properties of their constituents. The simplified finite element model uses springs in the connecting nodes between the fiber and matrix. A detailed finite element analysis, …
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Experimental and computational analysis of random cylinder packings with applications
… and they can serve as prototype models of fibrous materials and/or other particulate materials. In this research, comprehensive studies on cylinder packings were carried out by computer simulations and by experiments. The computational studies made use of a collective rearrangement …
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Dynamic response of thin-walled composite structures with application to aircraft wings
… effects arising from the anisotropic nature of fibrous composites, as well as due to non-coincident centroid and geometric shear centre of the beam crosssection, are the main contributory elements when developing the theory. The beam is subjected to time dependent forces and/or torques which can …
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Processing and Properties of New Anisotropic and Mechanically Active Polymeric Composites
… in this work to develop highly anisotropic fibrous composites. Previous work has detailed the properties of using electrospinning to fabricate fibrous anisotropic composites that was achieved by embedding stiff fibers in an elastomeric matrix. The goal of this work is to achieve anisotropic …
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Finite element micromechanics modeling of inelastic deformation of unidirectionally fiber-reinforced composites
… Periodic Models: Applications to Boron/Aluminum Composites): A simple and unified weak formulation and its convenient FE implementation have been proposed. The weak formulation is valid for any doubly periodic model under uniform 3-D macro-stress, and serves as a common rational foundation of …
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An investigation into a magnetic compaction technique for composite manufacturing
Submitted in fulfilment of the requirements for the degree of Master of Engineering: Mechanical Engineering, Durban University of Technology, Durban, South Africa, 2022.
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Characterization of structural changes in thermally enhanced Kevlar-29® Fiber
<p>The purpose of this exploratory investigation was to elucidate the structural mechanism accounting for the enhanced compressive properties of heat-treated Kevlar-29® fibers. A novel theory was set forth that hydrogen bond disruption and concurrent misorientation of crystallites may account for …
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Characterisation and development of carbon nanotube macrostructures
… zone of microfibres displays similarities to fibrous composites, with nanofibrils extending from each side of the fracture. In some microfibres, the stress-strain behaviour shows evidence of this as a “tail" artefact after fracture. One microfibre was studied in detail, showing a tail length …
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Fracture properties of fibre and nano reinforced composite structures
Submitted in fulfilment of Masters in Technology: Mechanical Engineering, Durban University of Technology, Durban, South Africa, 2007.
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Novel method for carbon nanofilament growth on carbon fibers
… with potential applications in structural composites. Employing a relatively new method, in which carbon structures are grown from fuel rich combustion mixtures on certain catalytic metals, multiscale filament structures were grown from ethylene/oxygen mixtures at 550 °C on commercial PAN …
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The development of a modified biaxial composite test specimen
Bi-axial testing of composite structures has been an important topic in the research community for some years now. Bi-axial test specimens in the past have typically been cruciform specimens with a tapered thickness gage section. This ensures that the specimen will fail under bi-axial loading …
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Modelling environmental effects on fracture damage of natural fibre-reinforced polymer composites
The behaviour of sodium hydroxide treated sisal fibre-reinforced polyester composite subjected to environmental ageing conditions has been studied with the aim of modelling its effect on the composite fracture damage for the purpose of long-term performance prediction. The composite was accelerated …
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Modelling environmental effects on fracture damage of natural fibre-reinforced polymer composites
The behaviour of sodium hydroxide treated sisal fibre-reinforced polyester composite subjected to environmental ageing conditions has been studied with the aim of modelling its effect on the composite fracture damage for the purpose of long-term performance prediction. The composite was accelerated …
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Fatigue performance of nanoclay filled glass fiber reinforced hybrid composite laminate
Submitted in fulfilment of the requirements for the degree of Master of Engineering: Mechanical Engineering, Durban University of Technology, Durban, South Africa, 2017.
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Metrology of optical telescope components
… such as carbon fiber reinforced epoxy (CFRE) composites can meet those requirements because of their nearly-zero CTE and potentially low CME. To employ these composite materials for telescope structural design, it is necessary to first develop practical and economical methods to determine …
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Large strain flexural testing of thin composite laminates
Carbon fiber composites are of significant interest for use in deployable space structures. Elastically folded thin laminates can be utilized as hinge mechanisms in structural systems such as solar arrays, reflectors, and instrument booms, allowing for compact packaging during launch to orbit. …