Guided Wave-Based Bondline Integrity Monitoring

The implementation of structural health monitoring (SHM) into aerospace 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 and characterization for bonded composite joints. Since the MDC SHM hardware is already quite mature, much of the Phase I effort will aim to customize piezoelectric sensors and diagnostic algorithms to best meet Navy requirements. MDC will evaluate the effectiveness of various types and configurations of piezo-sensor materials, perform sensor placement optimization, and develop customized algorithms for this guided wave based system. Finally, MDC will collaborate with Northrop Grumman to demonstrate the selected configuration using platform-relevant materials, and assess the performance.