Measuring both thermal and kinematic full-fields using a single CMOS camera during high temperature tests

Abstract

In numerous domains, both kinematic and thermal fields are sought to study temperature dependent phenomena. They are usually obtained by digital image correlation and infrared thermography, respectively. Although these techniques are well mastered, their combination is not straightforward since they need radically different conditions to work efficiently. This paper presents a procedure to measure accurately thermal and kinematic full-fields simultaneously using a single CMOS camera in a chosen region of interest. The kinematic field is measured by global digital image correlation and the thermal field by near-infrared thermography for temperatures above 700 ∘C. A procedure is detailed to identify the radiometric model and compute the thermal field without being affected by the heterogeneous emissivity of the sample surface caused by the speckle pattern. A methodology showing how to manage temperature measurements during high thermal transients is also presented. The proposed approach aims to be widely accessible since it does not need strong knowledge in DIC algorithms and only requires a standard camera. The method is first validated on a virtual test case, before being used on real experiments performed at high temperature with a stereo setup.