Application of Digital Image Correlation for Non-Uniform Residual Stress Measurement Using Incremental Hole-Drilling Method

The hole-drilling method is a well-established technique for measuring residual stresses, traditionally relying on strain gauge rosettes to capture deformation induced by material removal. However, optical measurement techniques such as Digital Image Correlation (DIC) offer significant advantages, including full-field deformation measurement and the elimination of complex strain gauge application procedures and the requirement for precise alignment of the rosette and hole. The applicability of DIC for residual stress measurement in steel specimens subjected to non-uniform stress distributions was investigated. Incremental hole-drilling experiments were conducted, utilizing full-field deformation data to evaluate residual stresses. A four-point bending fixture was employed to introduce controlled stress levels, allowing for direct comparison between measured and applied stresses. By varying the applied load, the feasibility of using DIC for hole-drilling residual stress measurements across different stress levels was assessed. The results confirm that DIC is a reliable and effective alternative to strain gauge rosettes for residual stress determination using the hole-drilling method.