Digital Image Correlation (DIC)
DIC 2D
Digital Image Correlation (DIC) is a full-field image analysis method, based on grey value digital images, that can determine the contour and the displacements of an object under load. DIC is very effective at mapping deformation in macroscopic mechanical testing, where the application of a speckle pattern provides the needed contrast to correlate images.
DIC Stereo
Stereo DIC is based on our DIC tracker which is stand-alone tracker in the software along with many other being used under TEMA/TrackEye. All the baseline architecture and tools remain the same as for the other trackers’ framework.
The Stereo version of DIC uses two cameras to pin-point the 3D-coordinates of all points in an area of a surface, this allows for 3D and 2D measuring of full field displacement and strain. The sophisticated algorithms calculate the complete strain tensors for the full-field solution, including many different strain formulations, such as Green-Lagrange, Euler-Almansi and Cauchy strain tensors. The camera calibration is done as in other applications, using a target or multiple points and a known distance.
Points of Interest, Inspection lines and Virtual Extensometers can be placed on the surface to measure strain at specific points or along specific lines. The Virtual Extensometer is similar to an actual extensometer and measures the distance between two points to achieve extension and engineering strain.
As qualifying data there is the sigma value, which indicates how well the correlation matched the different points. This variable can be displayed in a color diagram for easy overview of the worst areas.