Eigenstrain-based model for prediction of laser peening residual stresses in arbitrary three-dimensional bodies Part 2: Model verification

Abstract

This paper presents the results from a set of experiments designed to quantify the accuracy of the laser peening residual stress prediction model presented in Part 1. Firstly, a set of specimens containing common geometric features (e.g. corner radii and corner fillets) were machined from annealed 316L stainless steel plate. The regions around the geometric features were treated with laser peening and the resulting residual stress was measured using the contour method. Secondly, the laser peening residual stress prediction model was used to predict the residual stress produced by laser peening for the same set of specimens. A detailed comparison between the measurements and predictions is given in the form of contour plots and line plots of the measured and predicted residual stress. The results show that the model has a fair amount of agreement with the measurements over the range of geometry studied. Both the modelling and experimental results show that a decrease in the radius size for the corner fillet geometry results in an increase in the depth of compressive residual stress and a decrease in the magnitude of the surface residual stress. Both sets of results for the corner radius geometry show that a decrease in the radius size gives a decrease in the magnitude of the compressive surface residual stress. There is disagreement between the measurements and the predictions with respect to the relation between radius size and depth of compressive residual stress for the corner radius geometry.