PYRODYNAMICS DIC (DIGITAL IMAGE CORRELATION)

Digital Image Correlation is a non-contact optical measurement technique that tracks the motion and deformation of a specimen’s surface by comparing digital images taken before and during deformation. 

Principle of Operation

1. The surface of the specimen is prepared with a random speckle pattern so that each small area (subset) can be uniquely identified in images.
2. A series of images are captured during a mechanical test using one or more cameras.
3. Specialized software uses correlation algorithms to track how each subset moves between the undeformed (reference) and deformed images.
4. From this tracking, displacement fields are obtained. Spatial derivatives of displacement are used to compute strain fields, usually given as full-field maps over the specimen surface. 

Key Features

1. Non-contact: No physical sensors on the specimen — reduces influence on material behaviour.
2. Full-field data: Provides displacement and strain distribution over the entire visible surface rather than at discrete points.
3. 2D or 3D Measurement: Using a single camera for in-plane 2D or multiple cameras for full 3D surface mapping 

Typical Applications

1. Mechanical tests (tensile, compression, bending) to characterize material properties
2. Fracture and crack propagation studies.
3. Structural deformation analysis in laboratory and field conditions.