Inspection of Composite Adhesive Bonds with an Electrochemical Sensor

DACCO SCI, INC., (DSI), together with the Composite Materials and Structures Center of Michigan State University, proposes a Phase I SBIR program to use an electrochemical impedance spectroscopy (EIS)-based corrosion sensor to monitor the integrity of anadhesive bondline between two composites or one composite and a metal. Using this sensor approach to detect moisture intrusion into a bondline will give advance warning of potential environmentally induced bondline deterioration. Corrective action canthen be taken prior to permanent disruption of the bondline. Delaminations and kissing unbonds may also be detectable. This monitoring technology could eventually be used as a standard tool in the suite of nondestructive evaluation (NDE) methods forevaluating the integrity of bonded composites. Because embedded sensors are not required, both existing and future BMDO hardware could be inspected and monitored. Increased confidence and reliability of bonded composite structures wouldaccrue.Reliability of bonded composites will increase as a result of this health monitoring. Readiness and safety are also benefits to improved composite health monitoring. In addition to BMDO systems, military and commercial aircraft,composite-reinforced bridges, storage tanks, pipelines, and weapon systems and components are potential applications.