Durability Methods Development
Durability Methods Development

Author: S. D. Manning

Publisher:

Published: 1979

Total Pages: 82

ISBN-13:

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A critical evaluation of three analytical approaches is made to determine their applicability and/or potential for analytically assuring airframe durability during the design stage. A suitable analytical format for quantifying durability damage is developed based on U.S. Air Force durability design specifications and durability analysis needs. Air Force durability requirements are briefly reviewed and discussed. Three potential approaches for durability damage analysis are conceptually evaluated and discussed: (1) Conventional Fatigue Analysis (Palmgren-Miner Rule); (2) Deterministic Crack Growth Approach; and (3) Probabilistic Crack Growth Approach. The resulting evaluation provides the prerequisite work needed to develop a durability analysis methodology. The probabilistic crack growth approach is found to be the most promising for developing the durability analysis methodology under Phase I.

Evaluation of the Crack Growth Gage Concept as an Individual Aircraft Tracking Device
Evaluation of the Crack Growth Gage Concept as an Individual Aircraft Tracking Device

Author: F. J. Giessler

Publisher:

Published: 1983

Total Pages: 168

ISBN-13:

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An analytical and experimental program was conducted to evaluate the crack growth gage concept for application as an individual aircraft tracking device. Three gage designs were evaluated. Volume I discusses the evaluation of two versions of a stepped thickness gage and a stepped width gage. Volume II discusses the evaluation of a side-grooved constant thickness gage. An analytical evaluation of the change in transfer function corresponding to gage design parameter changes was performed to determine the configuration of the gages to be tested. Initial spectrum tests were conducted on the first stepped gage design to determine the ranking ability of the gage. Then constant amplitude tests were conducted on the second stepped gage design. A modification of the gage was made to improve spectrum test response. The modified gage was subjected to both constant amplitude testing and spectrum testing. The analytically derived crack growth rates were compared to the test data. In general, the analysis predicted slightly higher growth rates than observed.