Digital Image Correlation is a widespread technique that relies on imaging the deformation of a random pattern affixed at the surface of the test specimen. The technique tracks displacements of subsets of pixels between the reference and deformed configurations. The Photodyn group uses the MatchID DIC platform which integrates VFM identification as well as other features like synthetic image deformation from finite element displacement maps to realistically simulate measurements. DIC is well adapted to large strains and lower strain gradients whereas the grid method is generally better for small strains and higher strain gradients.

tensile_hole_unloaded2

Example of a speckle pattern

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MatchID commercial DIC/VFM software platform

Some resources

  • Sutton, M. A., Orteu, J. J., & Schreier, H. W. (2009). Image Correlation for Shape, Motion and Deformation Measurements: Basic Concepts, Theory and Applications. Image Correlation for Shape, Motion and Deformation Measurements: Basic Concepts, Theory and Applications, 1-321. doi:Doi 10.1007/978-0-387-78747-3
  • DIC Challenge
  • DIC training course