Guided Wave-Based Bondline Integrity Monitoring

This SBIR aims to develop a novel method for detection of bondline damage in composite joints. 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 as wing skins, 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 has demonstrated a digital sensor-bus, which minimizes SHM infrastructure and EMI susceptibility. During this SBIR, MDC further exploited this low-mass, long-range, scalable SHM architecture to satisfy Navy requirements for detection of bondline failure for ribs and other composite joints that are inaccessible inside the wingbox. During Phase I, testing was conducted at Triumph/Vought on actual Triton wing skin segments, demonstrating the ability to ascertain the integrity of bonded composite doublers following impact events. The Phase II effort will continue to mature this technique performing system-level sensor placement optimization, calibrating damage quantification algorithms, formulating a statistical probability of detection and qualifying packaging for the operating environment.