Comparison of the performance of ultrasonic non-destructive testing methods on inspection of fibre reinforced plastics

Speaker:
Heckel, Thomas; BAM Bundesanstalt fur Materialforschung und -prufung; Germany

Authors:
Blankschän, M.; Federal Institute for Materials Research and Testing (BAM); Germany
Brackrock, D.; Federal Institute for Materials Research and Testing (BAM); Germany
Gaal, M.; Federal Institute for Materials Research and Testing (BAM); Germany
Heckel, T.; Federal Institute for Materials Research and Testing (BAM); Germany
Hosseini, S.; Federal Institute for Materials Research and Testing (BAM); Germany
Lodeiro, M.; National Physical Laboratory (NPL); United Kingdom
Maierhofer, C.; Federal Institute for Materials Research and Testing (BAM); Germany
Schadow, F.; Federal Institute for Materials Research and Testing (BAM); Germany
Ségur, D.; CEA, LIST; France

ID: ECNDT-0155-2018
Session: Composite Material - UT 2
Room: G1
Date: 2018-06-14
Time: 14:30 - 14:50

In the last twenty years, components made of fibre-reinforced plastic became a prominently used material in safety-relevant structures. Periodic in-service inspection of these structures using reliable non-destructive testing methods became a relevant issue in the field. The goal of the EMRP-funded project VITCEA (Validated Inspection Techniques for Composites in Energy Applications) aims on the evaluation of the performance of various non-destructive testing methods on the inspection of fibre-reinforced plastics.
In this talk the results of the comparison of different ultrasonic testing methods will be discussed. There are two challenges for the ultrasonic inspection of fibre-reinforced plastics. Firstly, different material properties of the fibre and the resin cause anisotropic acoustical behaviour of the material. Secondly, the physical layout of fibre layers leads to complex structures of fibre-reinforced plastic parts, and thus to a complex acoustical response. Both result in a reduction of the signal to noise ratio and make interpretation of measurement results rather extensive.
During the VITCEA project, the acoustical behaviour of fibre-reinforced plate materials has been simulated. Specimens with artificial flaws for the evaluation of the detection thresholds have been designed and manufactured.
Various mechanized ultrasonic testing methods including phased-array sensors, air-coupled transducers, immersion tank testing and contact technique have been evaluated on the specially designed specimen. Laboratory scale tests and a round robin test have been carried out. The probability of detection and the detection thresholds for each method have been estimated.