Development and Validation of 3D DIC Based Residual Stress Testing Method

The paper describes the methodology of residuals stress determination on the basis of displacement fields measurement near drilled holes by means of 3D Digital Image Correlation. Detailed information concerning testing procedure are presented and supplemented by exemplary tests results for steel sample uniaxially loaded to 300 MPa. Determined values of residual stress calculated with inverse method algorithm are compared to the ones obtained with traditional method with near the hole strain measurements by means of tensometric rosette. In both cases 2 mm mill was used to drill the flat bottom hole with 0.25 mm increase steps. The influence of FEM model geometry used to deliver correction terms to the analytical model, necessary in the case of blind holes, is discussed. Determined residual stress from DIC based method agreed reasonably with traditional method.