Health Monitoring of Composite Structures Using Carbon Nanotubes

The goal of the proposed project will be to develop a hybrid structural health monitoring (SHM) system that can detect both microcracks and localized damage/delamination in composite structures.  The hybrid system will combine the unique sensing capabilities of carbon nanotubes along with those of a piezoelectric sensor network to sense the location, nature and extent of damage.  This system combines the key capabilities of the research team in piezoelectric health monitoring (Acellent Technologies) and sensing of damage in composites using networks of carbon nanotubes (University of Delaware). In order to localize the detected damage using the carbon nanotube sensors, a thin dielectric film (SMART Layer) with distributed electrodes will be developed.  The distributed electrodes will be utilized to measure the conductivity at different locations across the structure.  The localized damage in the structure will be measured by the conductivity change from the electrically conductive carbon nanotube networks formed inside the polymer matrix.  Additionally, the SMART Layer will include an embedded network of piezoelectric actuators/sensors to detect/verify the localized cracks and delaminations.  The integrated SHM system will be able to detect initiation of damage and monitor its growth. BENEFIT: The innovation of proposed system has many advantages over the current NDE including: 1) Increased safety and reliability robust in-situ health monitoring (early warning system) 2) Complete damage information qualitative and quantitative characterization 3) Reduced ownership cost removal of unnecessary inspections and reduced vehicle downtime 4) Maximized lifespan of structures residual life estimate by prognosis  )