Embedded Sensing Capability for Composite Structures

This Small Business Innovative Research (SBIR) project is an in-situ, real-time and on-board composite structural damage detection and structural health monitoring (SHM) system/technique development using graphite fiber composite materials' multifunctionalproperties the way they are designed and manufactured, by measuring electrical conductivity changes. Unlike embedded or surface-mounted sensor applications using piezoelectric, acoustic emission, fiber-optic and MEMS sensors, this proposed compositestructural health monitoring system/technique is applicable to already fielded (in-service) weapon system composite structures as well as new composite structures to be designed and manufactured.The embedded senseor installation presents sensor impregnation/curing process difficulties, material (fatigue) property degradation due to foreign object material insertion, sensor repair-ability and reability problems, etc. Surface-mounted sensorinstallation also presents other unique problems. Such sensor applications also require a number of sensors/interface-connectors (I/O) that make the technology application impractical to composite structures. The proposed composite self-sensingsystem/technique overcomes the limitations of the above embedded and surface-mounted sensor applications. This proposed project presents an innovative and unique graphite composite structural self-sensing technology, and provides in-situ, real-time andon-board composite SHM means for diagnosis and prognosis of in-service composite structures used in military weapon systems as well as those used for commercial aviation and civil infrastructures. This SBIR will result in development of in-situ, real-timeand on-board composite structural damage detection and structural health monitoring (SHM) system/technique for military composite weapon systems as well as commercial aviation and civil infrastructures. The proposed self-sensing system/technique can beused to insure the structural integrity of composite weapon systems, and the sensing results can be used to predict the remaining useful life (RUL) of the composite weapon systems (diagnosis/prognosis).