The Fraunhofer Institute for High Frequency Physics and Radar Techniques FHR has developed an innovative method that can automatically and non-destructively monitor and identify defects in fiber composite materials during the production process. This capability was previously impossible, and it is particularly significant in the production of wind turbine rotor blades due to the potential for defects to cause undulation or incorrect and twisted fiber orientation in the material.
Defects in Fiber Composite Materials
Fiber composite materials, used primarily in wind turbine rotor blades, consist mostly of glass fiber-reinforced plastics. If they are not appropriately laid out, defects may occur, which could impact the proper functioning of the blades. Therefore, it is crucial to detect defects during the manufacturing of fiber composite materials.
The FiberRadar Project was a collaboration between Fraunhofer FHR, Ruhr University Bochum, FH Aachen University of Applied Sciences, and Aeroconcept GmbH. The project’s objective was to develop a measurement system that could enable the control of manufactured components with unprecedented precision, exceeding what was previously possible.
The FiberRadar project researchers have achieved a significant breakthrough in non-destructive and automated detection by developing a method for checking the alignment of the lower glass fiber layers. For the first time, a millimeter-wave scanning system comprising a radar, a fully polarimetric robot, and imaging software can identify defects during the production process without damaging the product.
The Radar System
The radar system used in the scanning process sends and receives signals in two polarizations, providing high-resolution imaging of fiber structures, thus making it easier to detect any defects in deeper layers. The use of radar in scanning individual layers enables researchers to identify anomalies in fiber orientation and non-destructively examine the entire material volume.
Refraction compensation is a process that enhances the quality of images used by a scanning system. It is particularly important in reducing unwanted refraction effects in deeper layers, and plays a crucial role in detecting defects in the material.
Failure to detect anomalies in fiber orientation can result in defects in the final product, affecting its performance. However, by utilizing radar technology to scan individual layers, researchers can non-destructively identify anomalies in fiber orientation and examine the entire material volume, thereby ensuring high-quality final product.
The FiberRadar project has developed a measurement system that allows for precise production and control of fiber composite materials, surpassing the levels of accuracy that were achievable previously. By adopting this production method, manufacturers can guarantee superior quality of their final product, ensuring it functions as intended.
In conclusion, the FiberRadar project by the Fraunhofer Institute for High Frequency Physics and Radar Techniques FHR is revolutionizing the production of fiber composite materials, particularly in the manufacturing of wind turbine rotor blades. The project’s non-destructive and automated detection method can efficiently detect any defects during the production process, resulting in a final product that is of high quality and functions as expected.