“Better Blade” – Project for an innovative testing method
Particularly for rotor blades in wind power stations, reliable predictions concerning the durability are indispensable. When do rotor blades fatigue, when get material defects visible? The behavior of the blades with respect to fatigue, i.e. the initiation and growth of structural defects, must be assessed before the system is put into operation. In order to improve the testing procedure for the certification of the rotor blades, the Rotor Blade Centre at the IWES under the responsibility of Dr. Arno van Wingerde has established the “Better Blade” project.
Falko Bürkner, project manager for rotor blade testing, summarizes the targets of the “Better Blade” project as follows: “The measuring method used until now, is no more sufficient for the latest generation of wind power stations. To optimize the required accuracy, we have analyzed the entire process, identifying the cable pull potentiometers as the essential weak point. Above a certain cable length, the response time of the arrangement increases, so that it becomes impossible to monitor highly dynamic load changes at the required precision. It will be unavoidable to replace this configuration by an optical 3D measurement system, which does not comprise any coupling between the device itself and the sample.”
The optical system MoveInspect HF has been examined carefully for this application and proved, that it is able to deliver highly precise results in real-time, not depending on the current displacement of the blade.