Assessment of measuring errors in DIC using deformation fields generated by plastic FEA

• Published in: Optics and lasers in engineering 2009-07, Vol.47 (7), p.747-753
• Main Authors: Lava, P., Cooreman, S., Coppieters, S., De Strycker, M., Debruyne, D.
• Format: Article
• Language: English
• Subjects: Deformation measurement; Digital image correlation; Exact sciences and technology; Finite element simulations; Fundamental areas of phenomenology (including applications); Imaging and optical processing; Instruments for strain, force and torque; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Mechanical instruments, equipment and techniques; Optical elements, devices, and systems; Optical processors, correlators, and modulators; Optics; Physics; Systematic errors
• ISSN: 0143-8166; 1873-0302
• DOI: 10.1016/j.optlaseng.2009.03.007

In this article, systematic errors that arise from different implementations of digital image correlation (DIC) techniques are analyzed. In particular, we investigate the influence of the adopted correlation function, the interpolation order, the shape function and the subset size on the derived displacements. These errors are estimated using numerically deformed images that were obtained by imposing finite element (FE) displacement fields on an undeformed image yielding plastic deformation of the specimen. This FE procedure simulates realistic experimental heterogeneous deformations at various load steps. It is shown that DIC is able to reproduce these displacements up to a satisfactory level if conscious choices in the above-mentioned implementations are made.