ACOUSTIC
EMISSION & NDT SCIENTIFIC PUBLICATIONS
Acoustic Emission Monitoring Of Small Wind Turbine Blades
Proceedings 21st ASME Wind Energy Symposium in
conjunction with 40th AIAA Aerospace Sciences Meeting. Reno, USA.
14-17 January 2002.
ISBN 1-56347-530-8
Joosse, P., A., Blanch, M., J., Dutton, G., A., Kouroussis,
D., A., Philippidis, T., P., Vionis, P.
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 are
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
are presented for the application of the methodology.