Citation
Canal Casado, Luis Pablo and González Martínez, Carlos Daniel and Molina Aldareguía, Jon M. and Segurado Escudero, Javier and Llorca Martinez, Francisco Javier
(2012).
Application of digital image correlation at the microscale in fiber-reinforced composites.
"Composites Part A: Applied Science and Manufacturing", v. 43
(n. 10);
pp. 1630-1638.
ISSN 1359-835X.
Abstract
Digital image correlation (DIC) is applied to analyzing the deformation mechanisms under transverse
compression in a fiber-reinforced composite. To this end, compression tests in a direction perpendicular
to the fibers were carried out inside a scanning electron microscope and secondary electron images
obtained at different magnifications during the test. Optimum DIC parameters to resolve the displacement
and strain field were computed from numerical simulations of a model composite and they were
applied to micrographs obtained at different magnifications (250_, 2000_, and 6000_). It is shown that
DIC of low-magnification micrographs was able to capture the long range fluctuations in strain due to the
presence of matrix-rich and fiber-rich zones, responsible for the onset of damage. At higher magnification,
the strain fields obtained with DIC qualitatively reproduce the non-homogeneous deformation pattern
due to the presence of stiff fibers dispersed in a compliant matrix and provide accurate results of the
average composite strain. However, comparison with finite element simulations revealed that DIC was
not able to accurately capture the average strain in each phase.
