Application of removing layer method in residual stress testing for aerospace plate

The residual stress of 7050-T7451 high strength aluminum alloy aerospace plate was tested by removing layer method. The difference of different standard test methods was compared, and the distribution law of residual stress of plates with different thickness were studied. The results show that the presence or absence of sink holes at both ends of the sample had no significant effect on the residual stress test results. There was no significant difference in residual stress measured by sampling at different width positions of the plate. The surface layer of the longitudinal specimens with thickness of 20 mm and 76 mm was the compressive stress zone, the subsurface layer was the tensile stress zone, and the center was the stress free or low stress zone. From the surface to the center, the longitudinal specimen of 165 mm thick plate was divided into tensile stress zone, compressive stress zone, tensile stress zone and low tensile stress zone.