Blades for offshore turbines have long since passed the 100 m threshold, and there is no end in sight. With increasing sizes and loads, the structural reserves of blades are being squeezed ever further by design engineers. Consequently, thorough validation at full-scale level is of the utmost importance to ensure reliability over the entire lifetime. However, as the size and weight of the blades increase, large-scale testing becomes not only more important but also more challenging.
New test infrastructure
Starting with the obvious, access to test infrastructure that can handle the latest prototypes can be a critical bottleneck on the path to certification. Fraunhofer IWES recently inaugurated a full-scale blade test rig for large offshore blades with a length of 115 m and above. With a maximum static load of 160 MNm and a fatigue range of 140 MNm, it is well equipped to test the next generations of wind turbine blades.