Residual Stress Test in Aluminum Alloy Thick Plate by Slit Warping Method

Transverse residual stress distribution along depth direction of 7050 T7451 aluminum alloy plates with thickness of 40, 80 mm was measured by the slit warping method, and the results were compared with those by stripping method. The results show that the transverse residual stress near the center (20–60 mm away from the surface) was tensile stress and that near the edge (0–20 and 60–80 mm away from the surface) of the 80 mm thick sample was compressive stresses measured by the slit warping method. The correlation coefficient between the residual stresses measured by slit warping method and stripping method was as high as 0.853, indicating that the slit warping method was accurate. The maxima transverse residual tensile stresses of the 40 mm thick samples were located at the sample center, and the maxima transverse residual compressive stresses were located at the sample surface. The maxima transverse residual tensile stresses of the 80 mm thick samples were located at the sample center; the maxima transverse residual compressive stresses were located at 12–16 mm away from the surface.