Digital Integrated Shearographic Camera for On-Wing Defect Inspection of Aircraft Components

Turbine engines and other on-wing mechanical components that undergo repetitive high loads can fail from internal stress, fatigue, and creep. Physical Optics Corporation (POC) proposes to develop a full-field, compact hand-held, borescope-based digitalshearing camera, based on a unique single-element integrated shearing optical head, with on-line data processing for non-destructive stress and creep detection and measurement. The high resolution system has built-in thermal load control, and is capableof taking snapshots of the device under test. The snapshots are taken over a relatively wide field of view compared to current systems, allowing the test to be performed on a large area at once. In Phase I, POC designed the system and demonstrated thefeasibility of the concept. Phase II will refine the system design, and component development will lead to optimal integration of a laboratory prototype that will meet Army requirements. The software for analyzing the fringes will be capable of yieldingquantitative stress values and qualitative characterizations of creep. The preliminary laboratory breadboard prototype will be developed by the end of the first year of Phase II, and a fully integrated system will be packaged and demonstrated by theconclusion of the two-year Phase II period.