AN ENERGETIC APPROACH TO PREDICT FATIGUE-CRACK INITIATION LIFE OF LY12CZ ALUMINUM AND 16-MN-STEEL

The local strain range is considered to be the main factor controlling the fatigue damage process. An energetic approach is applied to corre late the elastic-plastic stress and strain near a notch with the remot ely applied stress, Fatigue crack initiation lives of LY12CZ aluminum and 16 Mn steel are predicted from a knowledge of the uniaxial data in volving parameters such as the elastic modulus, strain hardening stren gth and strain hardening exponent. These quantities are contained and identified with the fatigue strength coefficient C which together wit h the equivalent stress range provide an estimate for the fatigue life of metals, The results agree well with the test data available in the open literature.