Study on the limit detection of defects by pulsed thermography in adhesive composite joints through computational simulation

摘要

In this paper the detection limit of lack of adhesive defects in GFRP adhesive composite joints was evaluated through a computational simulation model of active pulsed thermography technique. In this study, several simulations were carried out in order to evaluate the influence of the thickness of the collar, heating time and excitation energy on the detection limit of defects. In addition to these analyzes, it was also evaluated the reduction of the thermal contrast of the defects as a function of the thickness of the collar (depth of the defects) and thus it was possible to estimate mathematically the limit value of the thickness of the collar that allows the detection of the defects for each heating time. The results obtained showed that the pulsed thermography technique would be able to detect defects of lack of adhesive that are located up to 8.5 mm deep in this type of composite joint.