Fatigue limits of crack initiation and propagation at notched plates

The fatigue limits of crack initiation and propagation at the edge of an elliptically notched semi-infinite plate under completely reversed fatigue stress are determined theoretically. The theoretical fatigue limit of crack initiation is expressed in terms of plain fatigue limit, critical microcrack length and notch shape. The theoretical fatigue limit of crack propagation is derived in terms of threshold stress intensity factor, plain fatigue limit and notch shape. The theoretical results are shown to be in good agreement with Frost's experimental data.