Stamps for Pattern Applications for DIC or Markers Tracking

Digital image correlation requires a surface pattern to monitor deformation, and while spray paint is widely used for this purpose, it suffers from drawbacks such as limited reproducibility and poor control over speckle characteristics. This study aims to develop stamps to apply patterns with greater consistency and control, and to demonstrate that such pattern speckle performs comparably to traditional spray paint speckle. For that purpose, speckles were applied to polymer surfaces using two techniques, ink stamping of circular dots and conventional spray painting. Their quality was first evaluated through numerical assessments, followed by digital image correlation analyses under both small and large strains. Small-strain behavior was studied using synthetically deformed images based on sinusoidal displacements, while large-strain performance was assessed via uniaxial stretching of a holed elastomer sample. Both speckle application methods yielded similar results in terms of image correlation accuracy and robustness across deformation scales proving that the produced stamps offer a viable alternative to spray paint, providing significant advantages in terms of control, reproducibility, and customizability of the speckle pattern, without compromising performance.