Effect of Specimen Configuration and Loading Types on Fatigue Life of an Annealed 0.42% Carbon Steels

Abstract

In the present study, a unified crack growth law based on the small fatigue crack growth law was investigated using specimens with different configurations and loading types for the annealed 0.42% carbon steel. Then, a convenient prediction method of fatigue life was proposed. This small fatigue crack growth rate was uniquely determined by the modified small crack growth law, , despite of changing for specimen configurations and loading types. The constants of can be estimated by an empirical equation of without stress/strain gradient. Considered the effect of stress gradient for different specimen configurations and loading types, the stresses under bending loadings and specimen configurations was calculated from that under push-pull loading. Therefore, the fatigue life of the specimens with different configuration and under different loading types can be simply estimated through the fatigue crack growth law based on the only tensile strength of carbon steels. The availability of proposed method was confirmed experimentally by the results of several carbon steels.

The Effects of Corrosive Media on Fatigue Performance of Structural Aluminum Alloys

“…Metals 2016, 6, 160 7 of 12 levels reach the same conclusions [22]. Therefore, for the same material and stress level, the fatigue life of the former is obviously longer than that of the latter as shown in Figure 5.…”

“…As the same AA2024-CZ aluminum alloy, it was found that the effect of applied cyclic loading style on the fatigue life of AA2024-CZ aluminum alloy is obvious. This is because the stress (strain) gradient exists in the cross-section of sample under rotation bending cyclic loading style, but it does not exist in that under push-pull cyclic loading style although the stress ratio (R =´1) and the stress levels reach the same conclusions [22]. Therefore, for the same material and stress level, the fatigue life of the former is obviously longer than that of the latter as shown in Figure 5.…”