The initial research was carried out as part of a Knowledge Transfer Partnership (KTP) with Durham University and set out to optimise the test design and develop a faster and even more precise method for conducting the flapwise and edgewise fatigue testing simultaneously on a wind turbine blade.
The resulting fatigue analysis software, developed by the Offshore Renewable Energy Catapult in collaboration with Durham University and utilising extensive data from the company LM Wind Power, has been certified by renewable energy certification body DNV GL. The software ensures that the physical test loads replicate the service life damage over as much of a blade as possible. With data from the analysis, a bi-axial test can be designed and undertaken to more accurately represent the fatigue that a blade in the field would experience over its lifetime.
Bi-axial moves away from conventional methods of testing and can also be presented to a certification body. Having attracted significant interest from industry, the bi-axial testing method was used as part of the XL-BLADE DemoWind project, which validated an LM Wind Power 88m blade, one of the longest in the world at that time, and continues to be used as part of Offshore Renewable Energy Catapult’s blade testing methodology.