Wind energy – rotor blades
The Fraunhofer IWES is now starting construction work on a third rotor blade test bench at its Großer Westring site in Bremerhaven, Germany.
Once complete, the bench will be used to test state-of-the-art prototypes measuring 115 m in length and even more.
Some €19 million are set to be invested in the project bearing the name ‘Future Concept for Fatigue Strength of Rotor Blades Phase II’, which will see the construction of a testing infrastructure with a modular test block and the development of new methods for investigating subsegments. The site at the Fischereihafen offers the advantage that long blades which have been transported by sea have only a short distance to travel to the testing hall.
In the past five years, the dimensions of the latest generation rotor blades have grown from almost 90 m to 115 m and now measure the same length as a soccer field. This lighting-speed development has even exceeded the imagination of industry experts: the Fraunhofer IWES commissioned its 90-m test hall exactly ten years ago.
The dimensions have continued to grow and the two existing halls enjoy good capacity utilization, yet, up to now, the institute has lacked the appropriate infrastructure to accommodate requests to test XXL blades from international manufacturers. This is now to be remedied at the Bremerhaven site, and the bench is to be commissioned in summer 2022.
Since the testing of a rotor blade can take several months, the third test bench will not only boost capacity but also bolster Bremerhaven as an IWES institute location.
The rotor blade experts from IWES also hope to make testing more intelligent by developing new methods. One particular focus, for example, is on biaxial testing of complete blades. With this test method, the rotor blade is set in motion along its transverse and longitudinal axes in both the impact and pivoting directions and the structural behavior under load is measured using sensors.