Reduced Order Approach For Peening Stress Field Variability

A common goal in shot peening research is to connect operational parameters to resultant residual stress fields, providing a means to control and optimize the effectiveness of surface treatment. In practice, experimental measurements of residual stresses are often averaged values over regions that are large in comparison to an impact dimple. In fact, the stochastic nature of impact locations leads to residual stress fields that are distributed. Finite element peening simulations confirm this observation. The goal of this report is to connect operational parameters to localized fluctuations in residual stress through probabilistic reasoning (Figure 1). In particular, the development of a Poisson process model to predict variability in residual stresses over measurement regions comprising multiple impacts, as well as predicting asymptotic variability in residual stress at sub-impact measurement length scales.