Low cycle fatigue properties of 7050-T7451 aluminum alloy under different strain ratios

Abstract

The low cycle fatigue properties of 7050-T7451 aluminum alloy was studied. The low cycle fatigue properties of 7050-T7451 aluminum alloy at three strain ratios R = -1, 0.02, and 0.5 were measured by axial strain control method on MTS electro-hydraulic servo testing machine. In this research, the relationship between cyclic stress and strain at strain ratio R = -1 and the average stress relaxation effect of R = -1, 0.05 were given. The equivalent strain model was used to draw the strain-life curve for low cycle fatigue life data. The results show that under different strain ratios of 7050-T7451 aluminum alloy, the same strain amplitude in the high strain region leads to approximate fatigue life, and the effect of the strain ratio is only reflected in the low strain region.