Automated, Rapid Non-Destructive Inspection (NDI) of Large Scale Composite Structures

Composite aircraft structures present significant inspection challenges to most NDI methods. Most widely used NDI modalities, e.g. visual inspection and coin tap, have little or no relevance to composite aircraft. These are typically qualitative techniques that are difficult to replicate, and depend on subjective interpretation by the inspector. Visual inspection, which is still widely used for metal airplanes, is largely ineffective in composites, since most problems that occur leave no indication at the surface. Single point ultrasonic inspection (A-scan) is time prohibitive and its effectiveness relies on operator skill. In the proposed Phase I program, we will address the shortcomings of current thermography technology, in order to develop an automated, large scale NDI system suitable for on- aircraft inspection of large composite structures at a NAVAIR depot. The system we propose will build on the existing thermography knowledge base but, if successful, will address a significantly greater thickness range than current technology allows. It will also reduce the total cost of inspection because of substantial time savings with the added benefit of improved reliability of fidelity of depot level inspections.