Influence of notch (tip) radius on fatigue crack growth rate

The paper deals with the problem of fatigue crack propagation from notches in plates made of FeP04 steel and AA356-T6 aluminium alloy. The tests were performed under different stress ranges by keeping the nominal load ratio $ (R=0.1)$ constant. The specimens were weakened by nearly-sharp and blunt two-sided notches. The results of the fatigue tests were then reanalysed in terms of the J-integral range including influence of the notch. It was observed that the blunter notches are, the higher fatigue crack growth rate is.