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Full-Text Articles in Engineering
Time-Dependent Validation Of Finite Element Strain Distribution Of A Plastically-Deformed Plate Via Digital Image Correlation, Kevin R. Knapp
Time-Dependent Validation Of Finite Element Strain Distribution Of A Plastically-Deformed Plate Via Digital Image Correlation, Kevin R. Knapp
Theses and Dissertations
Generation of residual stress is an essential step in the generation of Goodman data via Air Force Research Laboratory's vibration-based fatigue test. Conventional Goodman data is constructed through uniaxial fatigue testing at a rate of 40 Hz, while the vibration-based testing excites stresses at 1,600 Hz in a stress state that is similar to those seen in gas turbine engine airfoils. A pre-strain procedure is conducted to form residual tensile stress, which serves as a steady stress when the specimen is subjected to fully-reversed vibration-based fatigue loads. This steady tensile stress is desired at the fatigue zone of the test …
Investigation Of Dynamic Store Separation Out Of A Weapons Bay Cavity Utilizing A Low Speed Wind Tunnel, Andrew D. Bower
Investigation Of Dynamic Store Separation Out Of A Weapons Bay Cavity Utilizing A Low Speed Wind Tunnel, Andrew D. Bower
Theses and Dissertations
Characterizing mission store trajectories as they separate from a weapons bay cavity is highly relevant to the Air Force mission. The flow around a weapons bay is unsteady. The unsteady flow can cause a mission store separation trajectory to be unpredictable, and such is the case for what some have termed a pitch bifurcation. Traditional wind tunnel testing is incapable of detecting a bifurcation because traditional wind tunnel testing records time-averaged data. In this study, an experimental testing system was developed and refined in order to support the time-accurate characterization of dynamic mission store separation events. A Motion Test Apparatus …