Extended Aging Theories for Predictions of Safe Operational Life of Critical Airborne Structural Components

Ko, William L. and Chen, Tony (2006) Extended Aging Theories for Predictions of Safe Operational Life of Critical Airborne Structural Components. Technical Report NASA/TP-2006-213676, Research Engineering, NASA Dryden Flight Research Center.

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Abstract

The previously developed Ko closed-form aging theory has been reformulated into a more compact mathematical form for easier application. A new equivalent loading theory and empirical loading theories have also been developed and incorporated into the revised Ko aging theory for the prediction of a safe operational life of airborne failure-critical structural components. The new set of aging and loading theories were applied to predict the safe number of flights for the B-52B aircraft to carry a launch vehicle, the structural life of critical components consumed by load excursion to proof load value, and the ground-sitting life of B-52B pylon failure-critical structural components. A special life prediction method was developed for the preflight predictions of operational life of failure-critical structural components of the B-52H pylon system, for which no flight data are available.

EPrint Type:	NASA Technical Publication
Keywords:	Empirical loading theory, Equivalent crack-growth theory, ESE critical stress points, Operational flight-life theory, Stress load coefficients
Subjects:	Aircraft/Project: B-52 (31 - 39) Engineering: (39) Structural Mechanics
ID Code:	928
Deposited On:	02 June 2006
Additional Information:	60 pages.