Digital Image Correlation (DIC) is an analytical technique that compares images of a specimen’s surface during testing to generate full-field strain maps. This technology gives you more information than a traditional point-to-point extensometer or a strain gauge and allows you to see the complete story of the material’s behavior beyond the stress strain curve.
Scientists and engineers have found dozens of useful applications for DIC including detecting cracks invisible to the naked eye, visualizing localized necking and discontinuous yielding, comparing differences in material behavior between two separate formulations, and analyzing strain on parts or components where a traditional extensometer is not feasible.
In our lab, we recently performed a test to ASTM standard D5766 for the open-hole tensile strength of polymer matrix composites and used DIC to see exactly where the strain was occurring. Using DIC, we were able to visualize where the strain on the specimen was concentrated and how it propagated through the material.