Numerical reconstruction of residual stress fields in thick mechanical components

To achieve optimal design of mechanical structures, particularly for fatigue and buckling resistance, it is crucial to consider residual stresses. Without precise knowledge of these stresses, generic loading assumptions, which can be highly conservative, are often applied for industrial applications. Consequently, it is essential to incorporate accurate residual stress fields into numerical models, based on real measurements, to enhance the fidelity of the analysis. This study introduces a workflow for stress measurement and reconstruction, applied to thick structures typical of the naval and nuclear industries.

First, thick high-strength steel sheets are bent to obtain specimens with a controlled residual stress state, which is then measured using deep-hole drilling and contour methods. Special attention is given to the influence of measurement parameters and their post-processing. These measurements are first used to validate a numerical simulation of the bending process.

Next, the experimental data are integrated into a numerical stress field using an eigenstrain reconstruction approach. To refine this method, the through-thickness hardening profile—measured by X-ray diffraction—is incorporated. The effectiveness of the hardening information use is demonstrated by comparing the reconstructed stress field with the finite element simulations of the bending process.