Real-time automated composite scanning using forced cooling infrared thermography

Abstract

The growing importance of reliable, rapid, and non-contact non-destructive evaluation (NDE) of parts/structures either during manufacturing or maintenance operations has promoted the development of real-time, automated, and in-situ methods. The major driving factors for automation of traditional NDE techniques, such as thermographic imaging methods, are savings in cost and time. In this work a novel real-time low-cost automated heating and cooling thermographic system is developed. The system implements a novel cooling mechanism along with heating elements to provide precise control of heating and cooling of inspected structures and was built using low-cost components. A carbon fibre reinforced plastic (CFRP) composite sample with flat bottom holes (FBH) was used to evaluate the effectiveness of the system. This system is coupled with a model to provide insights into system optimisation and show the potential that highly flexible inspection systems can be tailored for specific industrial requirements. The modelled heating and cooling process was important in determining which parts of the thermal profile would provide the best results. The system was assessed using three heating/cooling profiles: heating only (HO), cooling only (CO) and heating and cooling (HC). The results show that each method was equally as good as determining defects in the tested structure, with HC having the potential to outperform the others if optimised.