A range of plain carbon, carbon and manganese, and low-alloy cast steels have been tested in fatigue in bending with notches of radii from 0.125 to 25.4 mm. The number of cycles to produce a detectable fatigue crack correlated well with the range of stress-intensity factor divided by the square root of the notch-root radius, providing an adequate engineering method for design. Fatigue-crack propagation rates were also measured. Fatigue-crack propagation is anomalously high for fatigue cracks of 1.0 mm or less emanating from notches. This is thought to arise because of rapid fatigue propagation through the region of the Neuber particle.
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References
1.
RICEP.: Acier-Stahl-Steel, 1975, 40, 297.
2.
BARNBY and AL-DAIMALANIJ. T.: J. Mat. Sci., 1976, 11, 1979.
3.
BARNBY and AL-DAIMALANIJ. T.: ibid., 1976,11, 1989.
4.
NEUBERH.: ‘Theory of notch stresses’, 2nd edn. 1958: Berlin (Springer) (AEC Trans. 4547, US Dept. of Commerce).
5.
BSI, ‘Methods for crack-opening displacement (COD) testing,’ DD 19:1972.
6.
NEUBERH.: ‘Theoretical determination of fatigue strength at stress concentrations’, Tech. Rep. AFML-TR-68-20, 1968.
7.
BLUHMI.: ‘Fracture mechanics of aircraft structures’ (ed. H.Liebowitz), AGARDOgraph No. 176, p. 89, 1974.
8.
JOIINSONH. H. and PARISP. C.: Eng. Fracture Mech., 1968, 1, 3.
9.
BROWNW. F. and J.E.. SRAWLEY: ASTM STP No. 410, 1968.
10.
SMITHR. A., JERRAMK., and MILLERK. J.: J. Strain Analysis, 1974,9,61.
11.
SMITHE.: Proc. Roy. Soc., 1967, A299, 455.
12.
BARNBYJ. T. and DINSDALEK.: to be published.
13.
PEELC. J.: Ref. 7, p. 503.
14.
PEARSONS.: Royal Aircraft Est. Tech. Rep.71109, 1971.
