Cold expansion effects on cracked fastener holes under constant amplitude and spectrum loading in the 2024-T351 aluminum alloy

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Title Cold expansion effects on cracked fastener holes under constant amplitude and spectrum loading in the 2024-T351 aluminum alloy
Publication Type thesis
School or College College of Engineering
Department Mechanical Engineering
Author Warner, Jacob John
Date 2012-05
Description Current United States Air Force maintenance techniques require that any discontinuity (crack, pit, gouge, or other defect) detected in a hole be removed by oversizing the hole or replacing the part. What if cold expansion could be proved to extend the life of a cracked component well beyond the time to the next required inspection? This research investigates the effects of cold expansion on cracked holes. This research compares the fatigue lives of clean (no detected discontinuities) cold-expanded holes with the fatigue lives of holes cold-expanded after a 0.050 inch fatigue crack had nucleated. The experiments conducted herein investigate various stress levels under constant amplitude and spectrum loading conditions. The percent cold expansion is calculated for each specimen, and the amount of crack growth from cold expansion was measured. Finally, this work compares the tested fatigue lives with analytical predictions using Lextech Inc. AFGROW software utilizing an assumed 0.005 inch initial crack size to account for the benefit of cold expansion, consistent with most industrial aerospace damage tolerance analysis.
Type Text
Publisher University of Utah
Subject Cold expand; Cold expansion; Cold work; Crack; Fatigue; Spectrum
Dissertation Institution University of Utah
Dissertation Name Master of Science
Language eng
Rights Management Copyright © Jacob John Warner 2012
Format application/pdf
Format Medium application/pdf
Format Extent 6,914,500 bytes
Identifier us-etd3,87360
ARK ark:/87278/s6377qhx
Setname ir_etd
ID 195658
Reference URL https://collections.lib.utah.edu/ark:/87278/s6377qhx
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