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Full-Text Articles in Engineering
Creep Of Hi-Nicalon S Ceramic Fiber Tows At Elevated Temperature In Air And In Steam, Benjamin R. Steffens
Creep Of Hi-Nicalon S Ceramic Fiber Tows At Elevated Temperature In Air And In Steam, Benjamin R. Steffens
Theses and Dissertations
Structural aerospace components require materials to have superior long-term mechanical properties that can withstand severe environmental conditions, such as high temperatures, high pressures and moisture, whilst enduring the loads they are designed for. Ceramic-matrix composites (CMCs) are capable of maintaining excellent strength and creep resistance at high temperatures, which make them attractive candidate materials for aerospace applications, particularly in propulsion. Silicon Carbide (SiC) ceramic fibers have been used as constituent materials in CMCs, although oxidation of the SiC to SiO2 has been a known degredation mechanism. Recently developed near stoichiometric SiC fibers have shown significant improvements in thermochemical stability; …
Creep Behavior In Interlaminar Shear Of A Cvi Sic/Sic Composite At Elevated Temperatures In Air And Steam, Matthew T. Pope
Creep Behavior In Interlaminar Shear Of A Cvi Sic/Sic Composite At Elevated Temperatures In Air And Steam, Matthew T. Pope
Theses and Dissertations
This research investigated the interlaminar shear performance of a SiC/SiC ceramic matrix composite. The interlaminar shear performance was observed in compression of double notched specimens (DNS) at 1200°C in both laboratory air and in steam. Compression to failure tests determined the as-processed interlaminar shear strength and interlaminar shear creep tests were conducted with stresses ranging from -22 MPa to -16 MPa. Primary and secondary creep regimes were observed in all creep tests. The specimens tested in creep at -16 MPa in air achieved run-out, defined as 100 hours at creep stress. The residual strength decreased slightly after 100 h of …
Silicon Carbide Capacitive High Temperature Mems Strain Transducer, Richard P. Weisenberger
Silicon Carbide Capacitive High Temperature Mems Strain Transducer, Richard P. Weisenberger
Theses and Dissertations
Air Force Research Lab Air Vehicles directorate performs research on hypersonic vehicles. To verify materials or designs of hypersonic vehicles, they have a need to measure strain at temperatures exceeding 700°C. Strain sensors have the ability to measure strain. Strain is the deformation of materials due to internal stresses in a material. Internal stresses occur when a material is subjected to a force. Traditional strain sensors use Piezoresistive effects to measure strain, which is temperature dependent and making them unusable at high temperatures. This paper discusses a novel strain sensing device, sensing capacitance instead of piezoresistance. The strain sensor is …