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Full-Text Articles in Mechanical Engineering
Optimization Of A Multi-Aixs Electro-Mechanical Scanning System., Raul Urbina
Optimization Of A Multi-Aixs Electro-Mechanical Scanning System., Raul Urbina
Electronic Theses and Dissertations
This thesis presents efforts to enhance the system performance of an ultrasonic scanning machine. New developments in electronics are used to enhance the system performance. This work focuses on optimizing the system repeatability with a robust triggering system for the scanner. The robust triggering system applies new advances in programmable logic devices that make the replacement of complicated digital circuits possible. Modeling of wave propagation through anisotropic media is used to increase the system dynamic range. The model-based gain control compensates for variations in thickness and materials by controlling the excitation pulse amplitude. The automatic gain is implemented using integrated …
The Flexural Response Of Bolted Composite Panels At Elevated Temperature, Christopher Gary Malm
The Flexural Response Of Bolted Composite Panels At Elevated Temperature, Christopher Gary Malm
Electronic Theses and Dissertations
Carbon fiberlcyanate ester matrix composite panels with bolted connections to aluminum endplates were tested in four point bending at room and elevated temperatures. The specimens tested were subcomponents of the NASA X-38 Crew Return Vehicle. The X-38 is the proposed escape vehicle for the International Space Station, currently being constructed in Earth orbit. During reentry into the Earth's atmosphere, the composite aeroshell of the X-38 is expected to experience elevated temperatures, which makes accurate characterization of material properties at elevated temperature imperative to a sound design. Three varieties of specimens were tested: flat composite laminates, hat-stiffened composite laminates, and sandwich …