Real-Time X-Ray Inspection of Composite Aircraft Structures.

Composite aircraft structures were inspected to determine the feasibility of utilizing Real Time Radiography RTR for detection of defects, damage, and repair verification. The program included inspection of composite aircraft structural samples in the laboratory and an on site demonstration of RTR at the Naval Air Rework Facility NARF, Norfolk of actual composite aircraft structures. These advantages, along with the substantial savings in film costs, will greatly facilitate inspection and extend maintenance capability at all levels. The second part of the program consisted of developing a penetrant injection system that when coupled with RTR would greatly facilitate assessment of composite damage for delaminations and debonds. A prototype system was fabricated and inspections were performed on graphiteepoxy and boronepoxy structural samples to determine the feasibility of the technique. The major conclusions of this part of the report are that, for penetrant injection inspections with 20 aqueous lead acetate solution, RTR will detect 1 2 mils of solution in a test panel and 2 The extent of debonds and delaminations in the composite samples. Since the initial feasibility of a penetrant injection system has been demonstrated, SAI is proposing an additional study to develop a portable penetrant injection system that could be used at the 1 and 0 levels for assessment of impact damage for delaminations and debonds.