Full field imaging of composite structures combining DIC and IR thermography

Infrared Thermography (IRT) is a full-field measurement technique for evaluating defects or damage in a material by localized variation in the surface temperature observed using a thermal camera. Thermographic measurements on metals and other homogeneous materials is well established but the application of this technique to composites is relatively recent. In particular, the article focuses on the assessment of damage evolution using a combined thermomechanical analysis of the composite. The occurrence of damage in composite structure is accompanied by heat dissipation, which leads to temperature change on the specimen surface. Therefore, surface temperature analysis using an infrared camera can be applied to better understand the damage mechanisms and energy absorption in composites . The thermal images provide quantitative information about location and strength of hot spots and, in turn, of the impact induced damage. For instance, small amount of energy is dissipated during the formation of microcracks, which can be observed as small temperature increase in the thermal images, while fibre breakage causes large dissipation of energy and a corresponding local increase of temperature.