Intelligent Tomography Composite Structure Inspection

The U.S. Air Force (USAF) needs a solution for nondestructive inspection (NDI) of new advanced and complex composite bonded structures through fairing materials (or compounds) applied to the outer mold line (OML) to detect delaminations and disbonding. To address this need, Intellisense Systems, Inc. (Intellisense) proposes to develop an innovative Intelligent Tomography Composite Structure Inspection (ITOXIN) system for in situ, fast, and efficient one-sided access, noncontact NDI of large, complex, multilayered composite bonded structures in future aircraft. This system is capable of performing inspections through fairing materials (or compounds) with complicated geometry and detecting, identifying, spatially localizing, and evaluating delaminations and disbonding. The ITOXIN provides high-contrast three-dimensional (3D or tomographic) imaging of low-density materials, making it suitable for fast and efficient NDI of various low-density and lightweight composite materials. The ITOXIN hardware includes an industrial X-ray source with a slit collimator and a large-area high-resolution flat panel imaging detector attached to a linear moving stage, mounted inside of a single compact housing. Unlike conventional X-ray radiography and tomography (CT), ITOXIN requires only one-sided access to composite components/structures that need to be inspected. Thus, ITOXIN is suitable for 3D X-ray imaging of large composite aircraft components and structures with complex geometry. The ITOXIN Phase I laboratory prototype will be assembled and tested in experiments with fabricated coupons, as required by the USAF, to demonstrate its capabilities to detect 1 in. diameter disbonds between a composite laminate skin and bonded stiffener and use artificial intelligence (AI)/machine learning (ML) to detect delaminations and disbonding. We will estimate in experiments ITOXIN’s spatial resolution, sensitivity in relation to material density, and probability of detection of disbonding and delaminations. In Phase II, Intellisense will develop a completely automatic and autonomous ITOXIN prototype supported by a robotic arm and AI/ML software. This prototype will detect, localize and mesure composite delaminations and bondline disbonds for OML laminate thicknesses (ranging from 0.100 in. to 0.75 in. thick) and possessing bondline thicknesses from 0.030 in. to 0.100 in. Fairing material will be representative and applied to the OML surface per specifications and geometries. The capability to reliably detect 0.5 in. diameter disbonds within the OML laminate and/or bondline and distinguish the disbond depth location will be demonstrated using simulated coupons. The capability to scan large areas and generate a 2D map of inspection of results (i.e., C-scan) will be demonstrated as well.