EVITA Project: Comparison Between Traditional Non-Destructive Techniques and Phase Contrast X-Ray Imaging Applied to Aerospace Carbon Fibre Reinforced Polymer

Abstract

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 advanced primary and/or complex aerospace composite structures. Grating-based Phase Contrast X-Ray Imaging 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 paper presents a comparison of two traditional non-destructive techniques (NDT): ultrasonic through transmission (immersed and water jet) and ultrasonic phased-array pulse echo, with the developed phase contrast XRay Imaging applied to advanced aerospace carbon fibre reinforced polymer. Typical defects produced during manufacture is 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 Grating-based Phase Contrast X-Ray Imaging 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 Appl Compos Mater (2017)

Enhanced composite plate impact damage detection and characterisation using X-Ray refraction and scattering contrast combined with ultrasonic imaging

“…Limited research has compared ultrasonic and X-ray phase contrast imaging techniques for damage detection in fibre-reinforced composite plates. Gresil et al [24] used immersion through-transmission imaging and phased array pulse echo imaging to benchmark Talbot-Lau grating interferometry XPCi as a viable NDE technique.…”

Early Damage Detection in Composites during Fabrication and Mechanical Testing

“…Non-destructive inspection/evaluation (NDI/E) techniques are often employed for the detection, localisation, and quantification of flaws and damage. Widely researched methods include the use of X-rays [ 1 ], ultrasonic waves [ 2 ], eddy currents [ 3 ], shearography [ 4 , 5 , 6 ], and infrared thermography [ 7 , 8 , 9 , 10 ]. Though they improve safety and often minimise premature replacements, inspections can represent significant down-time and labour costs.…”

Phase-contrast and dark-field imaging for the inspection of resin-rich areas and fiber orientation in non-crimp vacuum infusion carbon-fiber-reinforced polymers

“…Since TLGI-XCT is capable of detecting scattering structures in the subpixel regime [64], requirements in spatial resolution for the identification of carbon fibers are considerably reduced. Therefore, carbon fibers as well as resin-rich areas in relatively large components can be characterized at once [65] and additional insights into resinrich areas in combination with local carbon fiber layup and orientation can be found. These insights provide additional, more detailed input for finite elements simulations and consequently enable more reliable predictions for service life.…”