NDT of wind turbine blades using adapted ultrasonic and radiographic techniques

The objective of this study was to adapt ultrasonic and radiographic techniques for the inspection of wind turbine blades and to compare the obtainedresults. The measurements performed show that radiographic techniques are capable of reliably detecting a number of structural defects within the blade. The adapted air-coupled ultrasonic technique, using Lamb waves, proved to be the most promising in terms of implementation as it only requires access to one side. However, the novel combination of contact pulse-echo and immersion techniques using a moving container of water identified the shape and size of defects better. Through comparisons of images obtained using both radiographic and ultrasonic techniques, different defect properties can be identified. Hence, the best results are achieved when both techniques are combined together.