Pulsed thermography inspection of adhesive composite joints: computational simulation model and experimental validation

We developed a computer simulation model using finite elements for the reproduction of physical phenomena found in active pulsed thermography of GFRP adhesive tubular joints. During the manufacture of the joint, defects such as the lack of adhesive were included in order to evaluate the ability of the active pulsed thermography technique to detect this type of material and joint configuration. The experimental results obtained with the thermographic camera were compared with a numerical approximation obtained through the simulation model developed in this study using the Comsol Multiphysics® software and, because of their similarity; it was possible to validate the computer simulation model. In both methods assessed in this study, it was only possible to detect the lack of adhesive when the thermographic test was performed from inside the joint, as, on the outer side of the joint, the defects' surfaces are at a depth greater than on the inner side.