A Gap and Tape/Tow Width Sensor for On-Line Quality Control of Automated Composite Lamination Processes

The proposed study will evaluate the feasibility of using an optical sensor (structured lighting/image processing) to detect gap and tape/tow widths for automated composites fabrication processes such as tape laying, tow placement, and filament winding. The sensor will serve as a real-time, quality-control monitor during fabrication, which will allow for production of consistently higher-quality structural aircraft parts. Accurate placement and alignment of the tape/tows during fabrication are directly linked to the mechanical behavior of a composite component. It has also been found that leaving small gaps during lay-up can be beneficial, but that overlaps are to be avoided. Thus, on-line inspection of gap and tape/tow widths can significantly improve the material properties of composites manufactured using these processes. Materials investigated will include graphite/epoxies, glass/epoxies, and Kevlar/epoxies. Although we are only demonstrating on epoxy materials, the sensor can be used on thermoplastic matrices as well. Phase I efforts will demonstrate the feasibility of the concept by inspecting flat, tow-placed materials under high speeds. A part will be fabricated under the Phase I effort with real-time collection and display of tape or tow placement quality data. A method by which this information can be incorporated into automated compensation for part fabrication will be identified. Phase II will extend the effort to non-flat surfaces, wide tapes, and to the development of a feedback control loop.