Estimation of peening effects of random and regular peening patterns

Shot peening and peen forming are respectively used to strengthen and form a component by blasting numerous shots on the component. A large number of analytical and numerical researches have focused on revealing the effects of various peening parameters. The shot impacting positions are usually supposed as a regular or random distribution, but there is a lack of intermediate measurand to connect the regular and random peening effects. This paper is aimed to estimate the peening effects of different peening patterns with different measurands, such as peening coverage and impacting density. Two types of 3D finite element (FE) models with regularly and randomly distributed shots are developed with dynamic-implicit solver of Abaqus. A theoretical equation for calculating random peening coverage is developed to calculate the coverage within an area with symmetry boundaries. The simulation results reveal the evolutions of indentation size, peening coverage and stress field. The equivalent forces on the cross section of plate corresponding to the induced stresses of regular and random peening are compared under the same coverage and impacting density respectively. Peen forming experiments with strict boundary constraints are performed to verify the simulation methods and agreement is observed.