Comparison between X-ray micro-computed tomography and optical scanning tomography for full 3D strain measurement by digital volume correlation

Abstract

In this study, we present three-dimensional (3D) measurements by digital volume correlation (DVC) with images from X-ray micro-computed tomography (XμCT) and optical scanning tomography (OST). In this article, we compare both techniques and we define their field of application by evaluating their measurement uncertainty in the case of rigid body translations, homogeneous strain tests and localised compression tests. For displacement, measurement uncertainty is around 0.037 voxel for OST and 0.049 voxel for XμCT which correspond to a measured strain about 0.1%. For larger strain, uncertainty increases with strain intensity but relative error remains constant about 10%. To resume, measurement uncertainties given by DVC are similar to the ones which we obtain generally for a two-dimensional (2D) study with DIC.