*** 9801489 Sofge This Small Business Innovation Research Phase II project will explore a new approach to detection, classification, and location of damage to structural composite parts, providing a means for sensing structural degradation such as delaminations, fatigue and other damage. Piezoelectric transducer technology may be used for sensing various structural properties such as stress, strain, and elasticity when sensors are mounted on, or embedded within, a material structure. Structures may degrade due to improper manufacture, duty cycle wear, impacts, and material corrosion. The advanced structural concept proposed here is the use of these sensors to measure changes likely to be damage to an aircraft part. The method is to use high-frequency acoustic signals to extract the vibration signature from a structure. This vibration signature is then compared with that of a normal undamaged structure and the signature changes are used by software to extract metrics related to the health of the structure. These metrics are then used to diagnose the severity of damage and to locate the damage on the structure. The software uses a statistically based technique which accommodates normal variation of the signature on a structure, while accurately identifying changes in the signature due to delamination and other structural damage. The advanced structural monitoring concepts being sought have potential for commercial use in the civil transportation industry for aircraft, automobiles, trucks and boats and in the commercial space industry for boosters and satellites. ***
