Real-Time Evaluation Of Wind Turbine Blades With Acoustic Emission Monitoring During Certification Tests – September 2002, Vol. 7 No. 09:

A. A. Anastasopoulos, D. A. Kouroussis, A. G. Dutton, M. J. Blanch, P. Vionis, D. J. Lekou, D R V van Delft, P. A. Joosse, A. Proust, T. P. Philippidis, T Kossivas, G Fernando


Within the scopes of a current EC-funded research project, Acoustic Emission (AE) monitoring has been extensively applied during laboratory testing of various Wind Turbine Blades. Baseline testing (both fatigue and static) of small-scale blades to failure, including several load-and-hold periods at intermediate stages prior to failure, has enabled the development of a fast and effective “grading” system (from “good” to “severely damaged”), based on the amount of critical Acoustic Emission hits appearing during the hold periods. Such hits are identified and sorted out automatically, after each period, using trained Supervised Pattern Recognition algorithms on the acquired AE data, incorporated into specially developed (within the scopes of the Project) software, while, furthermore, the blade is graded using the software’s predefined grading criteria. The whole procedure is applied on load-hold data, at anytime in-between testing stages and is evaluated during testing of large, commercial scale blades. Ultimately, the grading technique will, also, be applied for the evaluation of installed blades, with proof tests and on-site monitoring.