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

This investigation is devoted to the modelling and simulation of the residu al stress held resulting from the shot-peening process. In this dynamic ela sto-plastic analysis, single and twin spherical indentations were examined using the finite element method. The contact between the shots and the targ et was modelled using contact elements of the penalty function type. Attent ion was devoted to three related issues. The first is concerned with the ef fect 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 st ress trajectories and unloading residual stresses. Finally, the study exami nes the effect of the strain-hardening rate of the target upon the developm ent and the spread of the plastic zone. The results reveal the important ro le played by the shot and target characteristics upon the quality of the tr eatment, as measured by the mechanically induced residual stresses. (C) 199 9 Elsevier Science B.V. All rights reserved.