Non-Destructive Testing of Full Scale W/T Blade by Means of Acoustic Emission Monitoring During Controlled Static Loading


“Wind Energy for the Next Millennium”, proceedings of 1999 European Wind Energy Conference, March 1-5, 1999, Acropolis Convention Centre, Nice, France, pp 691-694
Pantelis Vionis, Dr. Athanasios Anastasopoulos, Vassilios Kolovos, Dimitrios Kouroussis


Acoustic Emission (AE) monitoring techniques were used during full-scale testing of a 12 m long wind turbine blade at CRES Full Scale Blade Testing Laboratory. AE data were recorded in real time by a ten-channel AE system.  The loading envelope included static stepwise loading of the blade in its flapwise direction as well as unload-reload cycles and load hold periods. The AE measurements were complemented by usual mechanical measurements such as load and strain distribution along the blade.  AE data processing included data filtering and application of the various location techniques.  The intensity of AE sources/events during the various loading stages was characterised by means of statistical techniques. The results of the static tests revealed damage initiation and weak zones on the blade with high AE activity, which were further verified by visual inspection during subsequent testing.