Comparison between traditional non-destructive techniques and phase contrast x-ray imaging applied to aeronautical carbon fibre reinforced polymer

The EU-project EVITA (Non-Destructive EValuation, Inspection and Testing of Primary Aeronautical Composite Structures Using Phase Contrast X-Ray Imaging) aims at bringing Grating-based Phase Contrast X-ray imaging technology to Non-Destructive Evaluation and Inspection of primary and/or complex aeronautical composite structures. Grating-based Phase Contrast X-Ray Imaging (XPCI) is based on the so-called Talbot-Lau interferometer, which is made of the combination of a standard X-ray apparatus with three transmission gratings as documented in the literature.
This study presents a comparison of three traditional non-destructive techniques (NDT): ultrasonic through transmission and ultrasonic phased-array, infra-red thermography (IRT), and X-Ray computed tomography (X-Ray CT) with the developed phase contrast X-Ray Imaging applied to aeronautical carbon fibre reinforced polymer (CFRP). This comparison process will concentrate on carbon fibre laminates. Typical defects produced during manufacture will be examined as part of the testing and validation procedure. The following defects have been identified as being those most likely to be detected more effectively by the XPCI process than other state of the art industrial NDT techniques: porosity, foreign objects, cracks, resin rich, cut fibres, and wavy fibres. The introduction of this innovative methodology is expected to provide the aeronautical industry with a reliable and detailed insight of the integrity of thin and thick composite structures as well as of complex geometry ones, such as integrated closed boxes and sandwiches.
This paper will first present the grating-based phase contrast X-Ray imaging developed in this project applied to Aeronautical carbon fibre reinforced polymer. It follows with a discussion of the comparison methods on porosity and cracks detection.