Short crack growth kinetics and fatigue life of materials

Kinetics of short crack growth has been studied in cylindrical specimens with a shallow notch in 316L steel and in aluminium-lithium alloy. The crack growth rates of short cracks have been analysed and a general equation for the growth of an equivalent crack has been proposed. Two contributions to the crack growth are considered, one resulting from the external stress distributed homogeneously and the other from the strain and stress concentration due to the crack. The integration of the crack growth law yields the possibility to predict the fatigue life.