Dual axis testing of wind turbine blades
Abstract: full-scale mechanical testing of blades is an integral part of the certification of wind turbines. With ever-larger rotor diameters, the importance of testing and validation is growing with the aim of minimizing operational risks. Dual axis testing can lead to a more realistic loading scenario compared to traditional single axis testing. A recent demonstration at Fraunhofer IWES revealed that spring elements and decoupled masses can be used to tune the system frequencies, resulting in a representative dual-axis test.
Full-scale mechanical testing
In the race to maximize annual energy production (AEP), rotor diameters are continuing to grow. The increasing size of the turbine blades means that fewer test facilities are able to accommodate mechanical testing of the latest blade models. Limiting factors for the capacity to test turbine blades are the length of the test hall and the hall height, which is required to accommodate the large deformations during both static and dynamic testing. However, the most crucial factor is the ability of the test rig to bear both static and fatigue bending moments.