Strain-Cycle Fatigue of Sheet and Plate Steels III: Tests of Notched Specimens 830176
The effect of steel grade on reversals to crack Initiation in notched specimens 2Ni essentially reflected differences in tensile strength. The higher strength grades (B80RK,RQC100) required a greater value of the notch parameter KfΔS for a given 2Ni than the lower strength grades (1020,A36,B40PO). Stress ratio R had a significant effect on 2Ni with 2Ni 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 2Ni and the relation between the predicted and observed values.