Prediction of Peen Forming Stress and Curvature with Dynamic Response of Compressively Prestressed Target

Shot peen forming shapes the thin-walled components by introducing residual stresses in the near-surface layer. The residual stresses are controlled by peening parameters. It is essential to understand the evolution of peening stress and relate control parameters to the peening stresses. The finite element (FE) simulation is available for the analysis of the peening process, but still takes up a lot of machining time when it involves tons of shot impacts. This paper focuses on the evolution of peening stress and the relationships between peening stresses and representative shot impacts. Single impact and multiple impacts were studied by FE simulation with different kinds of compressive prestresses. The impact stresses were represented using mathematical expressions and stored in a database. Based on the database, an approach was proposed to predict peening stress evolution. Results of stress from theoretical predictions were close to the results from random peening simulations. Both predicted and simulated results of forming curvature of the peened plate were compared to the results of shot peen forming experiments. Results from theoretical prediction, simulation, and experiment show a good agreement.