Shot Peening Intensity and Residual Stress Distribution on Cylindrical Surface

Abstract

Shot peening is applied to shafts and pipes to improve fatigue strength. In this study, the peening intensity and residual stress distributions on the cylindrical surface were investigated for shot peening. When fixing the cylinder, the peening intensity varied depending on the position of the cylinder, because the collision angle γ between the cylindrical surface and the shot was greatly affected by the position. The function approximation method for estimating the peening intensity distribution was studied. The peening intensity was proportional to sin γ, and the modified Gaussian distribution approximated the peening intensity on the cylindrical surface. The residual stress distribution on the surface was different from the peening intensity distribution, and the compressive residual stress was highest when the central angle α was around 45°. The maximum compressive stress was on the surface when α was 45° and inside the cylinder when α was 0°. The rotation angle with uniform intensity was determined by the approximation method. When the cylinder was rotated at that angle, the compressive residual stress distribution on the cylinder surface became uniform. However, it was noted that the cylindrical surface had a history of peening at different collision angles γ.

 

This Paper was Originally Published in Japanese in J. JSTP 61 (2020) 239–243. Figures 2, 6, 7, 8, 9, 10, and 12 were slightly modified.