The effect of steel grade on reversals to crack initiation in notched specimens essentially reflected differences in tensile strength. The higher strength grades (BBORK,RQCI00) required a greater value of the Neuber notch parameter for a given life than the lower strength grades (1020,A36,B40PO). Stress ratio R had a significant effect on life with life increasing as R decreased from 0 to -1. The various predictive models studied (local strain, nominal stress, empirical) gave similar results in terms of the variability in estimates of life and the relation between the predicited and observed values.
With G. A. Miller, "Strain-Cycle Fatigue of Sheet and Plate Steels III: Test Method Development and Data Presentation" in High Strength Steel for Automotive Use, P-124, Society of Automotive Engineers, pp 23-31, 1983.