NCDMM was awarded the effort to oversee the development of a system to automate an inspection method to detect defects in components for aircraft produced by automated fibre placement (AFP). The automated inspection system project is part of a 2012 Defense-Wide Manufacturing Science and Technology (DMS&T) program awarded to NCDMM through the AFRL at Wright-Patterson AFB.

For phase one of the project, NCDMM has been working with Ingersoll Machine Tools, Inc., based in Rockford, Ill., in the development of an on-tool inspection system for AFP.

With phase one development nearing completion, NCDMM extended invitations to a select group of suppliers to participate in a competitive process to partner with NCDMM and Ingersoll Machine Tools in the beta site implementation testing of the automated inspection system during AFP production. NCDMM chose ATK as its partner.

Fibre placement is a repeatable, cost-effective composite structure fabrication method that is widely used for both military and commercial aerospace programs using high-speed, AFP machines.

While AFP machines are designed and programmed for proper placement of tows-strips of composite material impregnated with a resin-when the groups of tows are deposited onto a tool by an AFP machine to form a composite structure, potential problems inherent to composite production can occur. As such, the fibres must be thoroughly inspected against a stringent set of criteria.

Under current inspection practices, production must be interrupted after each ply. Personnel visually inspect and manually perform measurements, identifying such defects as missing or twisted tows; gaps between tows; inaccurately placed tows; bridging, wrinkles, or splices; and foreign objects and debris. Manual inspection is extremely time consuming, laborious, and visually tedious as defects are difficult to discern. Inspectors must also document and track all defects.

With the automated system, inspections occur in real-time while the composite structure is being fabricated, alerting the operator and allowing defects and anomalies to be detected and repaired during the fabrication process. The developed system also includes an electronic database system to electronically document and track defects.