Guided Wave-based SHM of Composite Navy Propellers

The implementation of structural health monitoring (SHM) systems into naval applications has been hindered by component quantity, including sensors, cables, and acquisition/computation units, as well as data quality. Particularly for large-area applications such ship hulls, complexity of the implied system infrastructure can be impractical, and data effected by attenuation and EMI-pickup along analog cables. The payoff of reliable SHM would be the ability to detect/characterize in-situ damage for condition-based maintenance, thereby greatly reducing overall life-cycle costs. Metis Design Corporation (MDC) has demonstrated point-of-measurement datalogging and digital sensor-busing during prior Phase II SBIRs, which minimizes SHM infrastructure and EMI susceptibility. During the proposed SBIR, MDC will further exploit this low-mass, long-range, scalable SHM architecture to satisfy Navy requirements for damage detection in composite propellers. Previously developed analytical models will be modified to simulate the wave response for relevant material and geometry (as identified by commercialization partner Rolls-Royce). Piezoelectric-based guided wave methods will be used to interrogate the structure, and pattern recognition-based algorithms will be trained specifically for the detection of damage and characterization of its severity. Finally, MDC will instrument several representative specimens built by Rolls-Royce to generate probability of detection and accuracy versus damage size curves for the proposed method.