ACOUSTIC
EMISSION & NDT SCIENTIFIC PUBLICATIONS
Acoustic Emission Monitoring of a 12m Wind Turbine FRP Blade
during Static and Fatigue Loading
Emerging Technologies in NDT, 2000, pp. 59-66
D.
Kouroussis, A. Anastasopoulos, P. Vionis, V. Kolovos, Eds. D.
Van Hemelrijck, A. A. Anastasopoulos and T. Philippidis, A. A.
Balkema
The structural
integrity of a new, 12m, FRP Wind Turbine (W/T) blade was
assessed by means of Acoustic Emission (AE) monitoring
during full-scale, static and fatigue testing. The blade was
loaded at a single point. The static loading envelope
included stepwise loading, unload-reload cycles and load
hold periods in the flapwise direction. Fatigue loading was
applied by two hydraulic actuators, exerting forces at the
flapwise and the edgewise directions simultaneously. AE data
were recorded in real time by a ten-channel AE system. The
AE measurements were complemented by mechanical measurements
such as load and strain distribution across the blade. AE
data processing included data filtering and application of
various location techniques. The intensity of AE
sources/events during the various loading stages was
characterised by means of statistical techniques,
distribution and cumulative plots. The results of the static
tests revealed damage initiation and weak zones on the blade
with high AE activity, which were further verified during
fatigue loading.