NMR as a Probe of Absorbed Water in Graphite-Reinforced Plastic

Graphite-reinforced plastic (GRP) is being used increasingly in aircraft applications. This lightweight material, however, is difficult to inspect for impact damage. Generally, the damaged region occurs on the back side of the GRP, where it is least accessible. It has been noted that the damaged regions absorb more water from a humid atmosphere than the undamaged regions. We propose that nuclear magnetic resonance (NMR) detection of the absorbed water may be a feasible method of detecting and locating impact damage in GRP structures