Thin Mat Material Foreign Object Debris (FOD) Inspection System

Structural skins and other components of the latest generation of advanced military aircraft include fiber glass or quartz composite construction. Such materials are used in places where a low or moderate dielectric constant is required. Where this structure is installed, it is important for the dielectric properties to be consistent across the component. A spatially-varying dielectric permittivity can lead to reduced performance. The problem is that during the course of manufacture, it is possible for contaminants to enter the process and settle onto the dielectric thin mat material as it is being produced. Such contaminants may be conductive, which can have a significant impact on the dielectric properties of the resulting material. In a manufacturing facility where multiple material lines are made, it may be difficult to keep the equipment and the produced material contaminant-free. Compass Technology Group (CTG) proposes an in-line dielectric measurement fixture to address the Air Force’s need for an optimized nondestructive evaluation (NDE) system that can quickly and accurately detect and identify foreign object debris (FOD) in thin mat materials. The research effort include design, construction and testing of a prototype fixture on representative COTS materials.