Speaker
Description
InfraRed Thermography (IRT) enables real-time, non-contact thermal inspection without harming the object or producing hazardous radiation and provides two-dimensional temperature distributions to detect early signs of structural irregularities, supporting continuous structural health monitoring across various industries. While thermal imaging can reveal the presence of damages, it is extremely difficult to directly identify specific damage mechanisms due to overlapping effects in the measurement chain, including the heat source, thermal propagation, detection system, signal processing, and data interpretation. Therefore, a combination of numerical and experimental approaches is essential for a comprehensive study of the entire heat transfer process. Halogen lamps are commonly used in active IRT for defect detections due to the high intensity of their emitted radiant heat flux and affordability; however, modelling the radiant heat flux from these sources is challenging due to their non-uniform heating, which can lead to errors in defect characterizations and temperature measurements, requiring careful input calibration to ensure accurate simulation results. This study emphasizes the experimental characterization of the radiant heat flux emitted by a halogen lamp in terms of both its spatial and temporal distributions using a fluxmeter sensor, and the development of three-dimensional heat transfer models incorporating the derived heat flux for IRT measurement chain simulations. The simulation results are validated through experiments performed on an acrylonitrile butadiene styrene (ABS) plate using both pyrometer and IRT measurements. The outcomes provide a clear understanding of the radiant heat flux characteristics of the halogen lamp and enable the definition of accurate boundary conditions for active IRT simulations, thereby enhancing the reliability and accuracy of the numerical results. Validated results show strong agreement with the simulations in terms of the temporal evolution of temperature distributions. These findings confirm the effectiveness of the calibrated heat sources and the proposed heat transfer models, providing a robust framework to improve the accuracy of numerical simulations for defect and damage detection using the IRT technique.
Keywords: Non-Destructive Evaluation (NDE), InfraRed Thermography (IRT), IRT simulation, Heat transfer modelling, Radiant heat flux.
