Health monitoring of structural composites with embedded carbon nanotube coated glass fiber sensors

Structural health monitoring (SHM) seeks to provide ongoing monitoring of a structure's integrity. Current SHM approaches include embedding some type of sensor within the composite or applying a sensor to the outside surface of the structure. These sensors react to strain or other changes in order to detect damage. In this study, a novel, multi-modal, nanomaterial based sensor technology that can provide wide area detection of damage was used. The efforts presented here serve as a feasibility study into the incorporation of carbon nanomaterials into structural composites as sensors. The carbon nanotube (CNT) covered fiber (fuzzy fiber) sensors exhibit similar sensitivity to conventional strain gages and are more easily integrated into composite structures as the sensor itself is a composite. The fuzzy fiber strain gages can be used to sense strain within composite structures and can be readily integrated into the structural laminate to provide sensing over large sections and in previously inaccessible locations. The unique properties of the fuzzy fiber lends itself to application in a wide range of sensing tasks within a structural composite including strain, temperature, degradation, etc. The fuzzy fiber may be tailored so that the same basic sensor can be used for a multitude of sensing applications.