Acoustic Emission Monitoring During Certification Testing of Wind Turbine Blades


European Wind Energy Conference, Copenhagen, Denmark, 2-6 July 2001

A G Dutton, M Blanch, P Vionis, D Lekou, D R V van Delft, P Joosse, A Anastassopoulos, D Kouroussis, T Kossivas, T Philippidis, Y Kolaxis, G Fernando, A Proust


Wind turbine blade certification tests, comprising a static test, a fatigue test, and finally a residual strength test, often involve sudden audible cracking sounds from somewhere within the blade, without the operators being able to locate the noise source, or to determine whether damage (minor or major) has occurred. A current EC-funded research project is looking at the possibility of using acoustic emission (AE) monitoring during testing of fibre composite blades to detect such events and assess the blade condition. AE can both locate and characterise damage processes in blades, starting with non-audible signals occurring due to damage propagation at relatively low loads. The test methodology is discussed in the context of the blade certification procedure and results presented from a series of static and fatigue blade tests to failure in the laboratory. Inferences are drawn about small differences in the manufacture of the nominally identical blades and conclusions presented for the application of the methodology.