Abstract
Fatigue crack growth rates have been determined for very short corner and bore cracks developing from fastener holes. This was made possible by the use of a simple load programme which provided a contrasting fracture feature or marker. The programme consisted of a high-low-high switch of load ratio (R) usually in blocks of 100 loads. A constant Δσ was maintained within each block. The crack growth rate data for short cracks was in reasonable agreement with the published long crack data for 7075 and 7010 alloy. Strong retardation effects were in evidence and certain features of the fractures shed new light on the retardation models, and also on those of fatigue fracture itself.
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References
MIL-A-83444 (US specification).
S. Pearson, Fatigue crack initiation and propagation in half inch thick specimens of an aluminium alloy. RAE Technical Report 71109 (1971).
Engineering Sciences Data Unit, Fatigue crack propagation in aluminium plate, extruded bar and forgings. “Fatigue” Vol. 4, “Crack Propagation”, Item No. 75029 (1975).
J. C. Newman, Predicting failure of specimens with either surface cracks or corner cracks as holes. NASA TN D-8244 (1976).
T. T. Shih and R. P. Wei, ASTM STP no. 595 (American Society for Testing and Materials, Philadelphia, 1976) p. 113.
C. A. Stubbington, Metallurgia 68 (1963).
D. P. Rooke and D. J. Cartwright, Compendium of stress intensity factors. Figs. 78 and 80. (HMSO, London, 1976).
P. J. E. Forsyth and A. W. Bowen, The relationship between fatigue crack behaviour and microstructure in 7178 aluminium alloy. RAE Technical Report 78006 (1978).
L. R. Hall and R. W. Finger, Fracture and fatigue growth of partially embedded flaws. Proceedings of the Air Force Conference (1969). AFFDL Technical Report 70-144 (1970) pp. 235–62.
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Forsyth, P.J.E., Powell, P.M. Fatigue crack growth rates for very short cracks developing at fastener holes in 7075 and 7010 aluminium alloys. J Mater Sci 18, 1852–1862 (1983). https://doi.org/10.1007/BF00542082
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DOI: https://doi.org/10.1007/BF00542082