A study of cumulative fatigue damage in aluminum alloy 2024-T4

Experimental data were generated using 2024-T4 aluminum alloy specimens under stress ratios of ?1 and ?0.5 for low-high, low-high-mixed, high-low and high-low-mixed stress sequences.Analysis of the data using Kramer's equation has indicated that the predicted cumulative fatigue damage and fatigue life are in close agreement with experimental results for low-high and low-high-mixed stress sequences under all stress ratios, whereas the theoretical values for high-low and high-low-mixed stress sequences under all stress ratios are more conservative than those obtained experimentally.It is suggested that development of Kramer's equation be studied thoroughly for possible modification.