Combined use of confocal microscopy and DIC for 3D displacement vector measurement

Abstract

In the present paper the author describes the potential offered by the combined use of the Confocal Microscopy (CM) and Digital Image Correlation (DIC) to resolve the whole displacement vector in full-field fashion and with nanometric accuracy. By means of two different configurations of the same portion of the area under investigation, the surface profile retrieved at microscopic level by the CM functioned as a carrier for the DIC algorithm, both for a polished surface and an engineering standard roughness. The in-plane displacement components obtained by DIC were then used to extract the out-of-plane component from the profile information. After describing all steps that are necessary for applying the procedure, preliminary results of an indentation tests carried out on a polished steel specimen are reported and discussed.