Composite Evaluation Using Contact and Non-Contact Ultrasound Excited Thermography

In ultrasound excited thermography method, high energy ultrasound is used as exciting source which can stimulate the defects such as crack and disband to produce heat. The heat excited would lead to temperature increase. The surface temperature would be captured and recorded by a thermal camera and further analysis would done. In this method, the defect is selectively stimulated, which makes this method suitable for small crack detection. Compared to contact ultrasound excited thermography method in which the sample to be tested is contacted with the high energy ultrasound source, in non-contact ultrasound excited thermography method, the sample has no contact with the horn of the high energy source and the energy is coupled by air. The non-contact method is suitable for the application in which even and not very high ultrasound energy is required or the sample is fragile. CFRPs with impact damage and a composite component with cracks were inspected with these two methods, the results show that ultrasound excited thermography method is suitable for composite evaluation.