Multibody modeling of the shot peening process

Shot peening is a mechanical process in which a component surface is subjected to the collision of thousands of small steel shots so inducing a compressive residual stress field that improves its fatigue resistance. Conventional numerical techniques, such as finite element method, are prohibitive to model the entire behavior of the media stream over the entire treated component because of the high computational cost. An alternative is to base such an analysis on the rigid body mechanics. Here, a multibody system approach was used to model the global shot peening process when applied on a leaf spring. Two thousands shot spheres impelled by a two-wheel peening machine were included in the model. Both dimensions and peening parameters were extracted from an experimental test developed also in this study. Graphical results allowed finding out some important aspects as the media trajectories, media interference, and the identification of the high peening intensity points. All these aspects resulted to be important for evaluating the peening arrangement efficacy. In addition, the media velocity and the peening coverage, both indispensables to assess the treatment of the peened component, were also obtained.