An Integrated DEM-FEM Model for Shot Peening Applications

Abstract Shot peening is a commonly used technique for improving the fatigue life of machine components by inducing compressive residual stresses in the surface layers. This process involves plastically deforming the surface layers by impacting with spherical particles at high speeds. The induced residual compressive stresses resist crack propagation and thus increase the fatigue life. The intensity of shot peening, measured using the Almen test, is an essential quantity for ensuring shot peening effectiveness and repeatability. It depends on various process parameters such as the shot speed, shot size, shot material, impact direction, and flow rate. In this study, a novel computational model is developed to simulate the Almen intensity tests on a Type-C strip accurately. The model uses a coupled technique based on the discrete element method (DEM) and the conventional finite element method (FEM). The predicted Almen intensity values agree with analytically calculated values. Results from the parametric studies conducted to analyze the influence of various parameters on the Almen intensity indicate that many different combinations of these parameters can obtain a given Almen intensity although the residual stress fields may vary.