An indentation-based technique to determine in-depth residualstress profiles induced by surface treatment of metal components

A novel identification methodology is introduced in this paper for determining the residual stress profile induced into metal components by hardening surface treatments. The procedure is based on the indentation test, performed at different maximum penetration depths, supplemented by the numerical simulation of the experiment and by inverse analysis. Several provisions increase the effectiveness and diminish computing times and costs of the proposed identification tool, in view of its intended practical and repetitive use in industrial environments. In particular, a parametric analytical description of the expected residual stress profile reduces the number of unknowns, while an interpolation technique based on radial basis functions replaces most numerical analyses, to be otherwise performed by finite elements. The robustness of the proposed methodology is improved by the consideration of a proper orthogonal decomposition technique. The reliability of the results provided by the present approach is verified against the simulation of the test based on some available experimental data.