SBIR-STTR Award

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

Keywords:
Structural Health Monitoring, Piezoelectric Rosette, Macro-Fiber Composite Transducer Patches, Ultrasonic Guided Waves, Shear-Lag

This Phase II proposal aims at developing and demonstrating the impact/damage monitoring technology whose feasibility was shown in Phase I. The project objective is to demonstrate a new technique based on piezoelectric rosette nodes for (1) locating the points of impact or growing damage in realistic aerospace structures, (2) identifying the magnitude of the impact force, and (3) discriminating whether an impact has caused structural damage or not. These capabilities are not available to date, with the necessary accuracy levels, for aerospace structures which are complex in either materials (anisotropic, etc..) or geometries (multilayered, tapered, etc..). Phase II work will culminate with the assembly and the demonstration of an impact/damage monitoring prototype with capabilities (1) through (3) above. The Phase II work will be performed by Avanti Tech, LLC and by the subcontractor University of California at San Diego.

Benefit:
Commercial applications of the proposed technology will be found in the structural monitoring of impact/damage-sensitive aerospace structures in the military sector (USAF, Army, Navy, Marines, etc…) and in the civilian sector (Boeing 787, Airbus A380, etc..). The technology could also find applications in monitoring ship hulls, tanks, cars and other damage-sensitive structures.

Keywords:
Piezoelectric Rosettes, Ultrasonic Waves, Composite Materials, Structural Health Monitoring, Impact