Investigating the possibility of crack detection using digital image correlation with laser speckles

Detecting structural defects such as cracking and corrosion is largely achieved by techniques such as eddy current and ultrasonic testing. For this purpose, these methods require point-by-point scanning over the area of interest. Digital image correlation provides a cheaper and quicker testing method. In this method, imaging of the surface of the structure is performed during loading and unloading by using a suitable camera. In the traditional digital image correlation, to tracking the surface, an artificial pattern should be created on the surface. Creating a suitable pattern on large surfaces is so difficult. With the use of the laser source, a random laser speckle can be created on the sample instead of an artificial pattern. In this paper, the detection of a crack in a polycarbonate plate is investigated. The amount of strain around the crack is more than in other areas, and this issue can be completely detected by the method of digital image correlation with laser speckle. If the structure can be loaded easily, this method is a quick test to identify cracks.