ReliaBlade 2: Structural reliability and improvement of the cost efficiency of rotor blades, part 2 – Development of new design methods for rotor blades

At a glance

• Rotor blade failure means high costs and loss of revenue. It is often caused by damage in the blade structure.
• New concepts such as Industry 4.0 and digital twins can bring about improvements but are not yet viable from a technical or economic perspective.
• This is where the ReliaBlade 2 research project comes into play. The aim of this cooperation – probably the only one of its kind in the world – between blade designers and industry partners is to deepen understanding of the manufacturing process and the behavior of the rotor blades in operation utilizing new fatigue criteria and test methods among other strategies.
• Fraunhofer IWES, the project coordinator, focuses on the development of prediction models and experimental test methods.

The challenge

Rotor blades are among the most highly loaded components in a wind turbine. Damage leads to turbine downtimes, costly repairs, and loss of revenue. As such, the reliability of rotor blades is a key factor in the success of the energy transition.

The predecessor project, ReliaBlade 1, revealed that damage is often caused by specific component deviations and defects originating in the manufacturing process. However, the phenomena leading to rotor blade fatigue during operation are not yet fully understood. In addition, understanding of material and structural behavior has not been able to keep up with the growth of rotor blade dimensions: rotor blade damage occurs more often during the lifespan.

At the same time, the industry is continuing to evolve: concepts such as Industry 4.0, predictive maintenance, and digital twins can make a considerable contribution to extending rotor blade lifespans. However, the realization of such concepts remains economically and technically unviable.

The solution

This is where the ReliaBlade 2 research project, which builds on the findings of the predecessor project, comes into play. The concerted collaboration of all major German rotor blade designers is unprecedented and unique in this field. All project partners will use the same rotor blade design for their work packages.

The aim of the project is to gain a deeper understanding of the manufacturing process and the behavior of the rotor blades in operation. The scientists are developing and validating novel fatigue criteria for the design of rotor blades, a new approach for the evaluation and performance of full-blade tests, and methods for the creation of digital twins.

Fraunhofer IWES, the project coordinator, focuses on the development of prediction models and experimental test methods for the validation of rotor blade structures, their components, and their materials. The plan is to perform corresponding test campaigns on Fraunhofer IWES’ rotor blade test benches in Bremerhaven.

The international cooperation is another distinctive feature of this project. Scientists from the Netherlands will be performing their own blade measurements at Fraunhofer IWES. The results will be made available to all partners.

The added value

ReliaBlade 2 will contribute to making rotor blades more reliable and extending their lifespans. In this way, the project will support the cost efficiency of the German and European wind industries as well as boosting their competitiveness. The project’s international scope underscores the fact that it makes more sense for different countries to cooperate when researching a topic rather than conducting “the same” research in parallel.