Crack propagation behavior of 7075-T651 aluminum alloy under different stress ratios

Based on ASTM E647 standard, the crack propagation behavior of 7075-T651 aluminum alloy under different stress ratios was studied. The Paris model, Walker model and Forman model were used to fit the crack growth rate, and the applicability and accuracy of each model under different stress ratios were compared and analyzed. The results show that different stress ratios significantly affected the crack propagation threshold of the material, and the threshold values were close when the stress ratios were −1 and 0.1, revealing similar crack propagation resistance.