Optical Instrument for the Assessment of the Structural Integrity of Complex Systems

In Phase I we propose to develop an opto-acoustical sensor which will detect defects in materials and be used for structural integrity assessment and prognostics. Its operational principle is predicated on the observation that structural changes areaccompanied by changes of the vibrational pattern on the surface of the test object. A unique pulsed acoustic excitation source induces vibrational modes that are simultaneously measured at multiple locations, yielding a surface velocity map that revealsstructural phenomena occurring well within the bulk of the material. The system is applicable for detecting corrosion, metal thinning, cracks, disbonding, and delamination. Using advanced mathematical algorithms, the currently measured vibrational modescan be correlated with previous ones to assess the structural integrity of large-scale components of complex mechanical systems. Historical data obtained from established baseline conditions can then yield information on structural integrity at a laterdate. Careful attention will be paid to developing a robust instrument, insensitive to external impact and harsh environments. During Phase I we will develop an analytical model of this diagnostic tool, complete a performance analysis, verify itsexperimental operation and design the prototype. The prototype system will be built during Phase II.The proposed technique will benefit the military and commercial aerospace industry as well as other industries by enabling real-time inspection of criticalparts in complex systems, such as aircraft, missiles, ships and land vehicles, and subsequently predicting imminent failures. Owing to its efficient operation and large area coverage the proposed device will significantly reduce the financial resourcesthat are required for inspection, offering also the possibility of robotic inspection. The proposed device can find commercial applications in other fields that require vibrational mode analysis, such as the heavy machinery and power generation industries,and chemical plants. The method can be used in virtually any application where it is necessary to record whole-field vibration information.