A stereoscopic digital speckle photography system for 3-D displacement field measurements

Use of 3-D Digital Image Correlation to Characterize the Mechanical Behavior of a Fiber Reinforced Refractory Castable

“…The 3-D DIC method is based on both digital image correlation (DIC) [22] and stereovision, and was developed at the end of the last century [9,[23][24][25][26]. The technique uses a DIC algorithm to determine point correspondences between two images of a specimen acquired from two rigidly bounded cameras.…”

Full-field optical measurement for material parameter identification with inverse methods

“…As was already mentioned, this technique uses a random speckle pattern that is simply sprayed onto the surface of the object or that is offered by the texture of the specimen's material. The objective is to obtain an image with a varied and distinctive pattern, which enables the correlation algorithm to trace the subsets of the reference image in the deformed images [3,4]. The concept behind the DICT-software 2D matching algorithm is that the distribution of grey values in a rectangular area (subset) in the picture taken of the specimen in the undeformed state, corresponds to the distribution of grey values of the same area in the picture taken at the deformed specimen.…”

Characterization and Model Assessment for Impact Damage Evolution in Functionally Graded Composites Using a Novel Nanosecond Deformation Measurement System

“…Both drift and spatial distortion functions are assumed to have pre-defined forms. Using these functional forms, the distorted positions of a finite number of locations, (x,y) k , are determined for each image n. The process is repeated at N times, so that the distorted positions (x,y) kn , k=1,2,…,K, n=1,2,…,N, are determined 9 . This data forms the basis for the simulation process, with the long term goal of demonstrating the accuracy and robustness of the approach for SEM image analysis.…”

“…(10), the procedure described in [13] is employed to perform 9 In practice, 7 to 11 pairs of images are acquired during the calibration phase; the only requirement is that several translations in two orthogonal directions be performed. The number of pairs of images during the measurement phase will vary with the number of strain increments; for better estimation of B-Spline function it should be more than 6 pairs of images acquired.…”

“…For nominally planar objects undergoing in-plane motions, the 2D-DIC technique became one of the preferred optical methods for measurements in experimental mechanics. For general surface shapes with arbitrary motions, 3D-DIC (stereo-vision) employing at least two views to recording object positions has been shown to have general capability to measure 3D shape and full-field 3D motions [5][6][7][8][9][10][11][12][13] . Nowadays, 2D and 3D methods using computer vision are widely used in many applications, and commercial software is available [14] .…”