Theoretical and Finite Element Analysis of Residual Stress Field for Different Geometrical Features After Abrasive Waterjet Peening

Abrasive waterjet (AWJ) peening can be used for metal surface strengthening by introducing near-surface plastic strain and compressive residual stress. The present studies seldom focus on residual stress by AWJ peening of targets with different geometrical features. In fact, those targets usually exist on some machine parts including gear roots, shaft shoulders, and stress concentration areas. According to Hertz theory of contact and Miao's theoretical model for predicting residual stress of flat surface, this paper developed a theoretical model for investigating residual stress of targets with different geometrical features including concave arc surface, concave sphere surface, convex arc surface, and sphere surface. AWJ peening of targets with different geometrical features and different radii of Gaussian curved surface was simulated by ABAQUS. Theoretical results were consistent with numerical simulation results and published experimental results (H. Y. Miao, S. Larose, et al., 2010, "An analytical approach to relate shot peening parameters to Almen intensity," Surf. Coat. Technol., 205, pp. 2055-2066; Cao et al., 1995, "Correlation of Almen arc height with residual stresses in shot peening process", Mater. Sci. Technol. 11, pp. 967-973.), which will be helpful for predicting residual stress of gear roots, shaft shoulders, and stress concentration areas after AWJ peening. The research results showed that under the same peening parameters, sigma(max), sigma(top), d(max), and d(bottom) in concave surface (including concave arc surface and concave sphere surface) were the maximum; sigma(max), sigma(top), d(max), and d(bottom) in convex surface (including convex arc surface and sphere surface) were the minimum; for concave surface, sigma(top), sigma(max), d(bottom); and d(max) decreased, respectively, with target radius; for convex surface, sigma(top), sigma(max), dbottom; and dmax increased, respectively, with target radius.