Real-time In-situ Impact and Damage Locator in Anisotropic Aerospace Structures

This proposal is submitted by Avanti Tech, LLC, a new company founded in 2008 as a spin off from the University of California, San Diego (UCSD) NDE & Structural Health Monitoring group. In Phase I, the team will develop the technique of Piezoelectric Rosettes for the location of impacts in aerospace structures, which are complex in either their material constituents and/or their geometry. The Piezoelectric Rosette concept was first proposed in 2007 by the same UCSD researchers to circumvent the problems of conventional Time-Of-Flight (TOF) triangulation of Acoustic Emission (AE) events used for impact/damage location. Because the TOF triangulation usually assumes one value of AE wave velocity in the medium, it is inaccurate when the wave velocity changes with propagation direction (e.g. anisotropic composite panels, stiffened panels, multilayered panels, etc..) or with propagation distance (e.g. tapered sections). The proposed Piezoelectric Rosette technique does not require prior knowledge of the wave velocity in the medium, and it thus has the potential to provide more accurate AE source locations in complex aerospace structures. The 9-month work will first develop analytical models of the rosette response to AE waves, and subsequently test the technique on anisotropic panels subjected to realistic pendulum and gas-gun impacts. BENEFIT: The successful completion of Phase I work will lead to the concept demonstration of the Piezoelectric Rosette impact location in aerospace-type panels. The technique has the potential to revolutionize impact location strategies because it does not require prior knowledge of the wave velocity in the test structure, contrarily to the common AE triangulation methods. Hence the potential for more accurate impact locations in complex aerospace structures where the wave velocity changes either with propagation direction (anisotropic, multilayered or stiffened components) or with propagation distance (tapered components).   Once fully developed, the Piezoelectric Rosette technique can potentially replace TOF-triangulation in any impact-sensitive or damage-sensitive structure that is either heterogeneous or geometrically complex. Ideal applications will be military flying platforms (USAF, Army, Navy, Marines, Border Patrol, Coast Guard, etc..) as well as civilian composite flying platforms (Boeing 787, Airbus A380, etc..).  Commercialization efforts will include the filing of a provisional patent application, followed by communication with Boeing, Airbus and NASA to explore patent licensing interests.)