Phase-Shifting Interferometric Strained-Stress Analyzer Navy SBIR FY2010.2 Sol No.: Navy SBIR FY2010.2 Topic No.: N102-136 Topic Title: Phase-Shifting Interferometric Strained-Stress Analyzer Proposal No.: N102-136-0239 Firm: Physical Optics Corporation Information Technologies Division 20600 Gramercy Place, Bldg. 100 Torrance, California 90501-1821 Contact: Shilpa Pradhan Phone: (310) 320-3088 Web Site: www.poc.com Abstract: To address the Navy's need for a nondestructive inspection tool to measure strained stresses in metallic components, Physical Optics Corporation (POC) proposes to develop a new nondestructive Phase-Shifting Interferometric Strained-Stress Analyzer (PISSA) system based on absolute optical phase measurements with an electronic speckle pattern interferometer (ESPI). This system can nondestructively and quantitatively measure the state and magnitude of a sustained stress present in a primary aircraft structure and on complex surfaces to assess susceptibility to environmentally assisted cracking in structural components. The PISSA system will improve flight safety and reduce inspection cycles for aircraft during fleet operations and directly addresses the Navy need for a nondestructive depot-level inspection tool. In Phase I, POC will demonstrate PISSA system feasibility by constructing and testing a laboratory prototype and providing diagnostics to determine the potential for crack initiation resulting from hydrogen embrittlement. In Phase II, POC will refine the system design and develop and demonstrate a full-scale PISSA system that can be effectively implemented in an environment equivalent to that of Fleet Readiness Centers (FRCs) without significantly disrupting the workflow or degrading the reliability of the data. Benefits: The PISSA system will improve flight safety and reduce aircraft inspection cycles during fleet operations. Because the PISSA system can detect susceptibility to environmentally assisted cracking in any structural components, it will have application in civil aviation, heavy equipment manufacture, mining operations and industrial overhaul/repair centers. Other commercial applications include nondestructive inspection of large-scale composite materials such as parts for bridges and structures. With only slight modification the system can be used to enhance the state-of-the-art for commercial aviation engine testing and inspection that requires measurement of strained stress for structural components. Return