Digital image correlation (DIC) is an optical technique that combines image registration and tracking methods for accurate 2D measurements of changes in images. Correlation theories for the measurement of alterations in data were first applied to digital images in 1975 [316].
Where is digital image correlation used?
It has been used at NPL to examine a diverse range of material specimens including examining the evolution and uniformity of strain in materials testing, crack tip and crack propagation studies, detecting damage development in composites, structural deflections, high temperature strain mapping and dynamic vibrational
How accurate is digital image correlation?
This study shows that DIC can measure small-magnitude (<0.1%) homogeneous strain fields with satisfactory accuracy, as demonstrated by the good agreement between E and ν values determined using SG (reference values) and DIC technique.8 May 2018
How accurate is DIC?
The accuracy of DIC strain measurements tends to be around 10% below 0.3% strain (3,000 µe), with higher accuracies near 1% above 3% strain (30,000 µe). DIC strain measurement has been successfully tested to beyond 50% strain, with some applications achieving 100% strain.
How does digital image correlation work?
DIC works by comparing digital photographs of a component or test piece at different stages of deformation. By tracking blocks of pixels, the system can measure surface displacement and build up full field 2D and 3D deformation vector fields and strain maps.
What type of data you can get from digital image correlation method?
Digital Image Correlation (DIC) is a 3D full-field, non-contact optical technique to measure contour, deformation, vibration and strain on almost any material. The technique can be used with many tests including tensile, torsion, bending and combined loading for both static and dynamic applications.
What is digital image correlation used for?
Digital Image Correlation (DIC) is a precise, non-contact, and non-interferometric optical method used for measuring the displacement/deformation of a structural element/material subjected to external loading. The idea of the DIC method is based on the principles of continuum mechanics (rigid body mechanics) [12].24 Jul 2019
What is the role of image data interpolation in digital image correlation and why is it needed?
DIC is a subset based image correlation technique. The deformed position of the subset may not be at the integer location. Therefore, interpolation functions are used to obtain the gray intensity value at non-integer location.