3D eddy current scanner for CFRP

However, this is valid for defect-free material only. The Fraunhofer Institute for Ceramic Technologies and Systems IKTS develops eddy current based diagnosis systems (EddyCUS®) by which CFRPs can be tested along the process chain, from the raw carbon fiber material to the production of complete assemblies made of CFRP.

By developing a robot based 3D eddy current scanning system, the Fraunhofer Institute for Ceramic Technologies and Systems, branch Materials Diagnostics, accomplished an important step towards production-integrated diagnosis of CFRP. This system combines the following advantages:

­Contactless testing of 3D structures

­Compared to ultrasonic testing a superior lateral resolution and penetration depth

­Rapid adaptation to different testing tasks

­Ease of application without radiation protection or coupling media

­High velocity up to 500 mm/s

­Automatic compensation of unevenness at the testing surface

­High defect sensitivity due to multi frequency testing and direction dependent probes

Eddy current based testing methods use the electric properties of carbon fibers for quality evaluation. Because of their ease of application (without coupling media, no radiation protection necessary) they are especially suited for rapid close-to-production testing. Due to its generation of distortion-free conductivity images, the universally parametrizable eddy current scanner EddyCUS® of Fraunhofer IKTS can also be used at 3D structures. The component to be tested is digitalized process-integrated with a stripe-light camera. Based on an automatically calculated path, the robot guides the eddy current sensor orthogonally across the surface. The measuring results are composed to a scanning image (C scan).

 A fast adaptation to testing tasks is enabled by a virtually adjusted surface digitalization and surface calculation. Unevenness is compensated nearly completely to keep liftoff effects minimal. Besides high scanning velocity at high resolution, significant properties are preferentially sensor tracing on sloped, planar surfaces and a flexible parametrization of the easily interchangeable sensors. The standard device can capture a maximum surface of 300 x 300 mm at a velocity of 500 mm/s and a sample rate of 3000 S/s. In addition, the EddyCUS® software offers a sequential multi frequency recording of up to four frequencies. Together with direction dependent probes this allows an exact differentiation of defect types.

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Contact
Jun.-Prof. Dr.-Ing. Henning Heuer
Fraunhofer Institute for Ceramic Technologies and Systems
Branch Materials Diagnostics IKTS-MD
Phone +49 351 88815-630
henning.heuer@ikts-md.fraunhofer.de