Three-dimensional dynamic finite element analysis of shot-peening induced residual stresses

This investigation is devoted to the modelling and simulation of the residual stress held resulting from the shot-peening process. In this dynamic elasto-plastic analysis, single and twin spherical indentations were examined using the finite element method. The contact between the shots and the target was modelled using contact elements of the penalty function type. Attention was devoted to three related issues. The first is concerned with the effect of the shot velocity, size and shape upon the plastic zone development and growth, and unloading residual stresses. The second with the effect of the separation distance between two impinging shots upon the equivalent stress trajectories and unloading residual stresses. Finally, the study examines the effect of the strain-hardening rate of the target upon the development and the spread of the plastic zone. The results reveal the important role played by the shot and target characteristics upon the quality of the treatment, as measured by the mechanically induced residual stresses. (C) 1999 Elsevier Science B.V. All rights reserved.