The Boeing Company

University of Washington

Brian D Flinn

Sei-Hum Jang

Alex Kwan-Yue Jen

Gary E Georgeson

Zhengwei Shi

Ryan E Toivola

Scott R Johnston

Wesley L Holman

Gregory Robert Gleason

Eric Winter

Tucker Howie

There is provided a removable chromatic witness assembly, system, and method to monitor thermal events and impact events on a surface of a composite structure. The removable chromatic witness assembly has a plurality of chromatic witness geometric configurations separately coupled in an arrangement to one or more portions of a polymeric film layer. Each chromatic witness geometric configuration has a plurality of chromatic probes of a same type incorporated into an adhesive material. At least two of the geometric configurations have a different type of chromatic probes with a different sensing capability for thermal events and impact events on the composite structure. The polymeric film layer and the geometric configurations form the removable chromatic witness assembly in a form of a removable chromatic witness applique configured to be removably applied directly and continuously to the surface of the composite structure, and configured to monitor the thermal and impact events.

Removable chromatic witness assembly, system, and method to monitor thermal events and impact events on a composite structure

Improved methods of detecting thermal exposure are provided herein. The provided methods utilize initially dormant luminescent probes incorporated into a matrix to form a composite. When exposed to heat over a period of time, the luminescent probes are 'activated' through a molecular transformation initiated by thermal energy. The activated probes exhibit a luminescent profile based on the extent of thermal exposure, thereby providing an indicator of the thermal exposure experienced by the matrix. When the composite is used to produce a structural component of a vehicle (e.g., an aircraft), the methods provide a convenient, large-area indicator of thermal damage experienced by the structural component.

Detection of thermal damage of composites using molecular probes

A method of forming a composite material includes providing an uncured substrate. The method further includes applying a bond ply to the substrate and a peel ply to the bond ply. In some embodiments, the bond ply comprises a fiber veil, such as a glass fiber veil. The method further includes curing the substrate and removing the bond ply and peel ply from the cured substrate, thereby exposing an active surface on the substrate. Removing the bond ply and peel ply can create fractures in the active surface that increase the roughness and bondability of the active surface. In several embodiments, the composite materials described herein can be compatible with a wide range of adhesives, including room temperature adhesives.

Bond ply for adhesive bonding of composites and associated systems and methods

A coating system includes at least one polymeric coating layer comprising at least one fluorescent dye, wherein an optical behavior of the fluorescent dye changes as a function of a stress of the at least one polymeric coating.

Method of detecting inconsistencies in composite structures and stress sensitive coatings used therein

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Seattle, WA, United States of America

Brian D Flinn