Development & Application of Modulated IR Thermography in Non-destructive Evaluation of Composite Materials by an edge detection filter and a morphological attribute profile

In this paper, development of modulated IR thermography non-destructive test has been addressed to detect and evaluate artificial subsurface defects in composite materials by an edge detection filter and a morphological attribute profile. At modulated IR thermography, In order to stimulate the test specimen, the heat flux is applied periodically over the surface of the specimen and the thermal response is decomposed by the Fourier transform method to extract its amplitude and phase images. The non-uniform backgrounds in the obtained images often reduce detection ability. In order to improve the evaluation of this method, an edge detection filter and a morphological attribute profile were applied to the images. Finite element analyses were applied for different frequencies on the model that were simulated with common controlled defects in composite materials. The results of image processing were used in order to locate the defects and it was observed that this method increases the defect detection ability and decreases the possibility of losing the defects in these frequencies.