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- Fretting corrosion (2)
- Airplanes--Wings--Design and construction (1)
- Dynamics (1)
- Flexible structures (1)
- Load factor design (1)
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- Markov processes (1)
- Materials--Fatigue (1)
- Reliability (Engineering)--Mathematical models.Mechanical wear--Mathematical models (1)
- Research aircraft (1)
- Rigid structures (1)
- Shot peening (1)
- Space shuttles--Stability (1)
- Space vehicles--Dynamics (1)
- Strain (Mechanics) (1)
- Systems engineering (1)
- Titanium alloys--Fatigue (1)
Articles 1 - 5 of 5
Full-Text Articles in Aerospace Engineering
Fretting Fatigue Behavior Of Shot-Peened Titanium Alloy Tl-6al-4v Under Seawater Conditions, William Y. Allen
Fretting Fatigue Behavior Of Shot-Peened Titanium Alloy Tl-6al-4v Under Seawater Conditions, William Y. Allen
Theses and Dissertations
The fretting fatigue behavior of the shot-peened titanium alloy, Ti-6Al-4V, was investigated under a corrosive environment of synthetic seawater. Fretting fatigue tests were performed over a wide stress range to determine the effect of seawater at high and low cycle fatigue regimes. The results from this study showed: (1) seawater significantly reduces the fretting fatigue life of shot-peened Ti-6Al-4V at both high and low cycle fatigue relative to its counterpart in ambient laboratory conditions, (2) shot peening increases the fretting fatigue life of Ti-6Al-4V when tested under dry and seawater conditions relative to its counterpart of unpeened Ti-6Al-4V, (3) surface …
Analytical Results For A Single-Unit System Subject To Markovian Wear And Shocks, Daniel E. Finkelstein
Analytical Results For A Single-Unit System Subject To Markovian Wear And Shocks, Daniel E. Finkelstein
Theses and Dissertations
This thesis develops and analyzers a mathematical model for the reliability measures of a single-unit system subject to continuous wear due to its operating environment and randomly occurring shocks that inflict a random amount of damage to the unit. Assuming a Markovian operating environment and shock arrival mechanism, Laplace-Stieltjes transform expressions are obtained for the failure time distribution and all of its moments. Moreover, an analytical expression is derived for the long-run availability of the single-unit system when it is subject to an inspect-and-replace maintenance policy. The analytical results are illustrated, and their results compared with those of Monte Carlo-simulated …
Structural Design And Analysis Of A Rigidizable Space Shuttle Experiment, Raymond G. Holstein Iii
Structural Design And Analysis Of A Rigidizable Space Shuttle Experiment, Raymond G. Holstein Iii
Theses and Dissertations
AFIT is in the process of designing a Space Shuttle experiment designated as the Rigidized Inflatable Get-Away-Special Experiment (RIGEX) to study the effects of microgravity on the deployment of rigidizable composite structures. Once in space, the experiment will inflate and rigidize three composite structures and perform a vibration analysis on each by exciting the tubes using piezoelectric patches and collecting data via an accelerometer. This paper presents the structural and vibration analysis of the RIGEX assembly and inflatable composite tubes using ABAQUS Finite Element Analysis (FEA) software. Comparison of the analysis has been carried out with Eigenvalue/Eigenvector experimentation by means …
Optimization Process For Configuration Of Flexible Joined-Wing, Cody C. Rasmussen
Optimization Process For Configuration Of Flexible Joined-Wing, Cody C. Rasmussen
Theses and Dissertations
This study established a weight optimized configuration design of a joined-wing sensor-craft. The joined-wing aircraft concept fulfills a proposed long-endurance surveillance mission that contains an antenna structure embedded in the wing skin. The analysis was completed utilizing structural optimization, aerodynamic analyses, and response surface methodology. A sample of 62 joined-wing configurations were weight optimized. Each optimized structure was determined through a change of skin, spar, and rib thickness in the wing box by determining trimmed maneuver and gust conditions for critical flight mission points. Since the joined-wing concept has non-linear deformation characteristics, the structural optimization used both strain and buckling …
Effect Of A Variable Contact Load On Fretting Fatigue Behavior Of Ti-6al-4v, Andrew J. Jutte
Effect Of A Variable Contact Load On Fretting Fatigue Behavior Of Ti-6al-4v, Andrew J. Jutte
Theses and Dissertations
Effects of a variable contact load on the high cycle fretting fatigue behavior of Ti-6AL-4V were investigated. Experimental tests were performed using a new test setup capable of applying a contact load varying in amplitude, frequency, and phase and independently measuring shear forces on opposite sides of a specimen. Finite element analysis (FEA) of experimental and idealized loading conditions was performed and local mechanistic parameters and the Modified Shear Stress Range (MSSR) fatigue parameter were determined. Correlations between contact width, slip amplitude, fatigue life and a variable contact load were established with variable contact loading shown to have a damaging …