Abstract:
Digital image correlation, an optics-based strain measuring technique, has
gained popularity during the last decade. The practice of employing digital image
correlation-based measuring techniques in experiments has progressed dramatically
owing to many incorporated sophistications: ease of use, greater precision, extensive
measurement range, and stability of the results. While cutting-edge DIC measurement
systems are commercially available, their high capital costs make them unaffordable
for widespread usage. Several studies on establishing DIC-based measurement
techniques with experimental validation have been undertaken over the years. The
majority of prior DIC research concentrated on the testing of concrete, masonry, and
metal alloy specimens, and little effort was made in assessing materials with
substantial elongations.
This dissertation presents an innovative DIC-based measuring tool for capturing
surface deformation information with better precision. The proposed system is
composed of two commonly accessible digital cameras as well as MATLAB-based
algorithms. Uniaxial tensile tests of latex specimens are used to demonstrate the
aptness of the proposed approach in capturing substantial deformations, and
displacement estimates are validated against Vernier Caliper readings. A secondary
high-precision measuring tool, the Ncorr program, was used to validate the integrity
of the results produced by this technique.
According to the comparison of results, it is proven that the system is capable of
producing precise full-field displacement and strain maps with an apparent accuracy
greater than 96 %. Furthermore, the similarity of the contour plots obtained using the
proposed approach and outcomes of the Ncorr program verified the reliability of the
proposed technique.
Citation:
Nadarajah, S. (2021). Measuring full-field deformation of hyperelastic material using digital image correlation [Master's theses, University of Moratuwa]. Institutional Repository University of Moratuwa. http://dl.lib.uom.lk/handle/123/22547