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Full-Text Articles in Engineering
Solution Approximation For Atmospheric Flight Dynamics Using Volterra Theory, Ashraf Mohammed Kandeel Omran
Solution Approximation For Atmospheric Flight Dynamics Using Volterra Theory, Ashraf Mohammed Kandeel Omran
Mechanical & Aerospace Engineering Theses & Dissertations
This dissertation introduces a set of novel approaches in order to facilitate and enrich Volterra theory as a nonlinear approximation technique for constructing mathematical solutions from the governing relationships describing aircraft dynamic behavior. These approaches reconnect Volterra theory and flight mechanics research, which has not been addressed in the technical literature for over twenty years. Volterra theory is known to be viable in modeling weak nonlinearities, but is not particularly well suited for directly describing high performance aircraft dynamics. In order to overcome these obstacles and restrictions of Volterra theory, the global Piecewise Volterra Approach has been developed. This new …
Assessment Of Preliminary Design Approaches For Metallic Stiffened Cylindrical Shell Instability Problems, Vicki Owen Britt
Assessment Of Preliminary Design Approaches For Metallic Stiffened Cylindrical Shell Instability Problems, Vicki Owen Britt
Mechanical & Aerospace Engineering Theses & Dissertations
A preliminary design tool for metallic stiffened fuselage cylindrical panels subjected to longitudinal compression has been developed and validated by comparison to test results. Several methodologies for stiffened panel buckling and failure predictions were examined and evaluated. An appropriate level of analysis fidelity was determined for different failure modes and design details. Results from panel tests conducted to verify analytical methods used to design the Gulfstream V aircraft were presented. The panels were representative of four general skin/stringer configurations on the aircraft. Finite Element analyses and standard analytical methods were used to predict panel failure loads. The accuracy of the …
Life-Extending Control For A Highly Maneuverable Flight Vehicle, Si-Bok Yu
Life-Extending Control For A Highly Maneuverable Flight Vehicle, Si-Bok Yu
Mechanical & Aerospace Engineering Theses & Dissertations
This dissertation investigates the feasibility and potential of life extension control logic for reducing fatigue within aerospace vehicle structural components. A key underpinning of this control logic is to exploit nonintuitive, optimal loading conditions which minimize nonlinear crack growth behavior, as predicted by analytical fatigue models with experimentally validated behavior. A major simplification in the development of life extension control logic is the observation and justification that optimal stress loading conditions, as described by overload magnitude ratio and application interval, are primarily independent of crack length and therefore, component age. This weak relationship between optimal stress loading and structural age …