A Novel Approach for Residual Stress Estimation via Coda Wave Interferometry Using Time Shift and Stretch Analysis

Ultrasonic technology is widely used for nondestructive testing to assess material properties and defects within material. This study applies Rayleigh waves to determine near-surface residual stress profiles in materials, utilising the acoustoelastic effect, which links wave velocity to stress/strain states. We address the inverse problem of reconstructing stress and stress gradient profiles by using finite element (FE) simulations for data generation.While Coda Wave Interferometry (CWI) traditionally analyses coda waves, we adapt the technique to measure shifts and stretches in Rayleigh wave signals. This allows for the detection of minute stress-induced changes in the wavefield, enabling the quantification of residual stresses by analysing time-shifts and stretching between baseline and stressed conditions.FE simulations, integrating the non-linear Murnaghan model, offer high-resolution data on wave propagation in materials with varying stress profiles. Results demonstrate that the modified CWI technique can accurately reconstruct residual stress fields.