Health monitoring method for composite materials
OwnerKenneth S. Watkins, Jr., Shelby J. Morrisinventors
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Abstract
An in-situ method for monitoring the health of a composite component utilizes a condition sensor made of electrically conductive particles dispersed in a polymeric matrix. The sensor is bonded or otherwise formed on the matrix surface of the composite material. Age-related shrinkage of the sensor matrix results in a decrease in the resistivity of the condition sensor. Correlation of measured sensor resistivity with data from aged specimens allows indirect determination of mechanical damage and remaining age of the composite component.
Claims16
A method for monitoring the health of a composite structure comprising a polymeric structural matrix, the method comprising the steps of:
- disposing a condition sensor mechanically coupled with said polymeric structural matrix of said composite structure, said condition sensor comprising a polymeric sensor matrix and a selected quantity of conductive particles;
- measuring resistivity of said condition sensor with a pair of electrodes in a predetermined location wherein the predetermined location is defined by the location of said condition sensor;
- comparing said resistivity measurement with resistivity of an aged condition sensor;
- and
- equating said resistivity of said condition sensor to said health of said composite structure by associating a decrease in resistivity of said condition sensor over time to chemical aging of said composite structure and an increase in resistivity over time to a mechanical flaw of said composite structure between said predetermined location of said pair of electrodes.
A method for monitoring the health of a composite structure comprising a polymeric structural matrix, the method comprising the steps of:
- disposing a condition sensor in said polymeric structural matrix of said composite structure, said condition sensor comprising a selected quantity of conductive particles disposed in said polymeric structural matrix;
- measuring a resistivity of said condition sensor with a pair of electrodes in a predetermined location;
- comparing said resistivity measurement with resistivity of an aged condition sensor;
- and
- equating said resistivity of said condition sensor to said health of said composite structure by associating a decrease in resistivity of said condition sensor over time to chemical aging of said composite structure and an increase in resistivity over time to a mechanical flaw of said composite structure between said predetermined location of said pair of electrodes.
Dependencies are inferred from the claim text.