Proper Orthogonal Decomposition based algorithm for reconstructing missing displacement measurements by Digital Image Correlation

Digital Image Correlation (DIC) is an optical, contactless technique used to obtain full-field displacement measurements. However, there are situations during testing when obstacles obscure the camera’s field of view, preventing the capture of all displacements. This paper presents a method based on proper orthogonal decomposition (POD) that exploits the correlation between point displacements to reconstruct the missing data. The developed algorithm was tested in the context of elasto-plastic deformation of specimens, particularly in regions experiencing concentrated plastic deformation. The algorithm demonstrated exceptional performance, achieving an accuracy of well below 10% despite monitoring only 20% of the specimen during the experiment.