Fatigue of four metallic materials under asynchronous loadings: small cracks observation and fatigue life prediction

Abstract This paper is a continuation of previously published work. It presents the results of small cracks observation on the surfaces of fatigued specimens subjected to multiaxial loadings. Specimens were manufactured from four materials: PA38-T6 aluminum alloy, E235 and E355 non-alloy steels, and X5CrNi18-10 austenitic steel. Based on the cracking analysis, it was found that the aluminum alloy and low-alloy steels exhibited shear damage mechanism, while the austenitic steel showed the tensile damage mechanism. Fatigue life prediction was performed based on six popular damage parameters. A correlation between the observed damage mechanism and the fatigue life prediction quality was noted.