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Full-Text Articles in Engineering
Modeling And Effects Of Non-Homogeneous Infiltration On Material Properties Of Carbon-Infiltrated Carbon Nanotube Forests, Daniel Owens Snow
Modeling And Effects Of Non-Homogeneous Infiltration On Material Properties Of Carbon-Infiltrated Carbon Nanotube Forests, Daniel Owens Snow
Theses and Dissertations
This work investigates the material properties and production parameters of carbon infiltrated carbon nanotube structures (CI-CNT's). The impact of non homogeneous infiltration and the porosity of cross section regions, coupled with changes in designed geometry, in this case beam width, on the density and modulus of elasticity are compared. Three potential geometric models of beam cross section are proposed and evaluated. 3-point bending, SEM images, and numerical optimization are used to assess the validity of each model and the implications they have for future CI-CNT material applications. Carbon capping near exterior beam surfaces is observed and determined to be a …
Novel Methods For Composites Recycling Via Pyrolysis, Matt Jacobs
Novel Methods For Composites Recycling Via Pyrolysis, Matt Jacobs
Undergraduate Honors Theses
Composites are unique materials in many respects. When fabric woven from carbon fibers is joined with a thermoset resin in a controlled environment, it results in a very strong material, especially evaluated on a pound-for-pound basis against metals and ceramics. One aspect of this construction that provides great strength lies in the fiber-matrix adhesion which facilitates load transfer to the reinforcement of the composite. This fiber-matrix adhesion is promoted by the polarity of the usual thermoset matrices, and properly designed sizing materials coating the fibers. It’s a two-edged sword, though. Although the resin and the fibers are quite strong together, …
Axial Compression Behavior Of Unidirectional Carbon/Epoxy Tubes And Rods Before And After Impact, Ian Michael Oxborrow
Axial Compression Behavior Of Unidirectional Carbon/Epoxy Tubes And Rods Before And After Impact, Ian Michael Oxborrow
Theses and Dissertations
Compression tests were performed on damaged and undamaged rods and tubes made from unidirectional carbon/epoxy composite and lightweight core materials. Tested samples represent local members in an open, three-dimensional, composite lattice structure. Testing was performed in order to establish effective core materials to use in order to increase the buckling length of local IsoTruss® members while maintaining low weight. Members were formed from T700SC-12K-50C carbon fiber with UF6639-100 resin. Core materials consisted of 3/8-inch (0.953 cm) outside diameter Teflon® rods, Teflon® tubes, nylon rods, nylon tubes, Ertalyte® rods, and Duratron® rods. All 3/8-inch (0.953-cm) cores were each surrounded by 50 …
Damage Tolerance Of Unidirectional Carbon And Fiberglass Composites With Aramid Sleeves, Charles Andrew Sika
Damage Tolerance Of Unidirectional Carbon And Fiberglass Composites With Aramid Sleeves, Charles Andrew Sika
Theses and Dissertations
Unidirectional carbon fiber and fiberglass epoxy composite elements consolidated with aramid sleeves were radially impacted at 5 J (3.7 ft-lbs) and 10 J (7.4 ft-lbs), tested under compression, and compared to undamaged control specimens. These structural elements represent local members of open three-dimensional composite lattice structures (e.g., based on isogrid or IsoTruss® technologies). Advanced three-dimensional braiding techniques were used to continuously fabricate these specimens. The unidirectional core specimens, 8 mm (5/16 in) in diameter, were manufactured with various sleeve patterns. Bi-directional braided sleeves and unidirectional spiral sleeves ranged from a nominal full to half coverage. These specimens were tested for …
Damage Tolerance Of Buckling-Critical Unidirectional Carbon, Glass,And Basalt Fiber Composites In Co-Cured Aramid Sleeves, Michael D. Embley
Damage Tolerance Of Buckling-Critical Unidirectional Carbon, Glass,And Basalt Fiber Composites In Co-Cured Aramid Sleeves, Michael D. Embley
Theses and Dissertations
Compression strength after impact tests were conducted on unidirectional composite rods with sleeves. These elements represent local members of open three-dimensional composite lattice structures (e.g., based on isogrid or IsoTruss® technologies). The unidirectional cores composed of carbon, glass, or basalt fiber/epoxy composites were co-cured in aramid sleeves. Sleeve patterns included both bi-directional (unsymmetric) braids and unidirectional spiral wraps with sleeve coverage ranging from nominally half to full. The diameters were nominally 8 and 11 mm (5/16 and 7/16 in). The larger diameter had nominally twice the cross-sectional area, to quantify the effects of scaling. The specimens were long enough to …
The Composition And Distribution Of Coal-Ash Deposits Under Reducing And Oxidizing Conditions From A Suite Of Eight Coals, David R. Brunner
The Composition And Distribution Of Coal-Ash Deposits Under Reducing And Oxidizing Conditions From A Suite Of Eight Coals, David R. Brunner
Theses and Dissertations
Eighteen elements, including: carbon, oxygen, sodium, magnesium, aluminum, silicon, phosphorus, sulfur, chlorine, potassium, calcium, titanium, chromium, manganese, iron, nickel, strontium, and barium were measured using a scanning electron microscope with energy dispersive spectroscopy from deposits. The deposits were collected by burning eight different coals in a 160 kWth, staged, down-fired, swirl-stabilized combustor. Both up-stream and down-stream deposits from an oxidizing region (equivalence ratio 0.86) and reducing region (equivalence ratio 1.15) were collected. Within the deposits, the particle size and morphology were studied. The average particle cross-sectional area from the up-stream deposits ranged from 10 - 75 µm2 and had a …
In-Situ Testing Of A Carbon/Epoxy Isotruss Reinforced Concrete Foundation Pile, Sarah Richardson
In-Situ Testing Of A Carbon/Epoxy Isotruss Reinforced Concrete Foundation Pile, Sarah Richardson
Theses and Dissertations
This thesis focuses on the field performance of IsoTruss®-reinforced concrete beam columns for use in driven piles. Experimental investigation included one instrumented carbon/epoxy IsoTruss®-reinforced concrete pile (IRC pile) and one instrumented steel-reinforced concrete pile (SRC pile) which were driven into a clay profile at a test site. These two piles, each 30 ft (9 m) in length and 14 in (36 cm) in diameter, were quasi-statically loaded laterally until failure. Behavior was predicted using three different methods: 1) a commercial finite difference-based computer program called Lpile; 2) a Winkler foundation model; and, 3) a simple analysis based on fundamental mechanics …