ISSN: 1945-7553
CODEN: JTEVAB
Page Count: 4

A Test Procedure for Determining the Influence of Stress Ratio on Fatigue Crack Growth

FitzGerald, JH
Research analyst, Northrop Corp., Hawthorne, Calif.

Wei, RP
Professor of mechanics, Lehigh University, Bethlehem, Pa.

Abstract

A test procedure is outlined by which the rate of fatigue crack growth over a range of stress ratios and stress intensities can be determined expeditiously using a small number of specimens. This procedure was developed to avoid or circumvent the effects of load interactions on fatigue crack growth, and was used to develop data on a mill annealed Ti-6Al-4V alloy plate. Experimental data suggest that the rates of fatigue crack growth among the various stress ratios may be correlated in terms of an effective stress intensity range, Δ Keff, at given values of Kmax.

This procedure is not to be used, however, for determining the corrosion fatigue crack growth characteristics of alloys when non-steady-state effects are significant.

Keywords:
fracture mechanics, fatigue (materials), crack propagation, tests, stress stress ratio, titanium alloys

Paper ID: JTE10076J
DOI: 10.1520/JTE10076J
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