Robust self-sensing Smart Fastener system interfaced with onboard HUMS

Fatigue cracks originating at fastener thru-hole locations are a primary damage mode in multi-layered joints. If these cracks remain undetected, a joint failure can follow with potentially catastrophic consequences. In-hole inspection of joints is difficult, costly, and time consuming. A sensor integrated with a fastener capable of detecting cracks in the borehole surfacei.e. a Smart Fastener - would significantly reduce the maintenance burden for aircraft operators. A Smart Fastener is far superior to manual inspection methods for layered joints as it is capable of continuously monitoring a borehole, without disassembly of the structure. The goal of the current program is to fully develop a Smart Fastener for damage detection in multi-layer aircraft structures. Previous work done in this area will be used as a basis for the development. The program will demonstrate the robustness of the enhanced Smart fastener in relevant operational environments and its capability for usage in actual aircraft structures while interfaced with the aircraft onboard HUMS system. The work will be done in close collaboration with Sikorsky Aircraft who is supporting the development. Phase I will demonstrate feasibility of the Smart Fastener in crack initiation detection. Complete fastener development will be done in Phase II.