A critical analysis of fatigue-crack propagation data for 2024-T3 aluminum.
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Authors
Kish, Robert Alan
Subjects
fatigue prediction
crack growth rate
crack closure
fatigue-crack growth data
crack growth rate
crack closure
fatigue-crack growth data
Advisors
Lindsey, G.H.
Date of Issue
1974-12
Date
December 1974
Publisher
Monterey, California. Naval Postgraduate School
Language
en_US
Abstract
Fatigue-crack growth data for 2024-T3 aluminum was used
to evaluate the accuracy of Forman's equation. Forman's
equation was found to predict from one-third to twice the
observed cycles to a given crack length when applied to
multiple cyclic stress ratios. An alternative approach
was developed, based on the observed data, which is
applicable to analog or digital fatigue-crack growth
prediction. Data acquisition based on constant increment
of crack length has been found to yield inadequate definition
of the crack-growth curve in the low-cycle range for the
successful application of the method. An expression was
developed which extends the application of the crack-closure
concept to the entire range of cyclic stress ratio. An
effective root-mean-square stress was defined which shows
indications of good correlation with the magnitude of the
crack-growth curves.
Type
Thesis
Description
Series/Report No
Department
Aeronautics
Organization
Naval Postgraduate School (U.S.)
Identifiers
NPS Report Number
Sponsors
Funder
Format
Citation
Distribution Statement
Approved for public release; distribution is unlimited.
Rights
This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.