Neutron radiography of composite materials - a comparison study of advanced NDE imaging techniques

A comparison study of advanced nondestructive evaluation (NDE) imaging techniques demonstrates the merits of using neutron radiographs to characterize defects, particularly cracks, in fiberglass epoxy composites with stainless steel interfaces. Neutron radiographs of mockups of the arm pivot sockets used on the Hard Upper Torso of the Extravehicular Mobility Unit Spacesuits showed hairline cracks not detectable by x-ray radiography, x-ray computed tomography or ultrasonic C-scan images. The ultrasonic C-scans were more effective for detecting disbond and delamination defects associated with the composite material and stainless steel interface. A conceptual method of integrating nondestructive evaluation images from various techniques to generate mosaic images is introduced for enhancing detectability of flaws by using the optimum features of each NDE imaging technique.