Characterisation of Indentation‐Induced Pattern Using Full‐Field Strain Measurement

Abstract: In this study, digital image correlation (DIC)‐based strain analysis software was successfully developed. Its strain resolution lies in the order of 2.3 × 10^?4–3.1 × 10^?4. Full‐strain field measurement was used to study indentation‐induced plastic patterns around the spherical indenter for a polycrystal and a single crystal of pure aluminium. During indentation, the pure aluminium specimen of the single crystal revealed a symmetric indentation pattern of von Mises strain. The piling‐up around the residual impression was successfully and directly characterised by examining the sign of strain ?_X and ?_Y in the X and Y directions. However, the inward, out‐of‐plane movement results in an error in calculating in‐plane strain referred to as a ‘distortion strain’ using two‐dimensional DIC.