Effect of Scratching and Bending Degree on the Residual Stress of the 7055 Aluminum Alloy Plate

Abstract

Abstract This study investigated the effects of scratches and bending on the surface stress of aluminum alloy plates with varying thicknesses. The purpose of this study was to provide guidance for surface stress testing of plates with different thicknesses. The “birth and death” element method was used to simulate the generation of surface scratches, while the stress field under the pre-stretched state was obtained through the displacement of one end of the board by 2.5%. The X-ray residual stress analyzer (μ-x360 s) was used to experimentally characterize the stress level on the surface of the plate. The research results showed that the residual stress level near the scratches decreases significantly, while the surface stress level of the plate decreases significantly after bending. The changes in stress values with increasing bending degree for plates of different thicknesses showed that the thicker the plate, the greater the tensile effect on the surface of the plate, resulting in smaller compressive stress. The longitudinal non-uniformity of the plates with different thicknesses was also analyzed, and it was found that the testing error of stress testing results was within ±5 MPa. In conclusion, this study provides useful guidance for the accurate measurement of surface stress on aluminum alloy plates of varying thicknesses, considering the effects of scratches, and bending.