Fastener Attrition Sensing Transducer (FAST)

Under this SBIR topic N16-009, Metis Design Corporation (MDC) has presented a method for detection of damage in complex fastened joints. Rotorcraft have been at the forefront of Condition Based Maintenance (CBM). For nearly 20 years, Heath & Usage Monitoring Systems (HUMS) have been used on rotorcraft such as the H-60, CH-53E, and V-22 to collect prognostic data to reduce preventative maintenance costs and increase asset availability. The majority of HUMS data collected today relates to drive system components, such as monitoring vibration off gears, bearings, shafts and rotors.  The proposed technology would expand CBM capabilities beyond HUMS hardware to be able to also capture fatigue damage in complex fastened joints. Many Structural Health Monitoring (SHM) systems in development can detect damage on flat structure, but features hidden in a multi-layer stack can be extremely challenging for conventional technologies. Under this effort, MDC focused on the use of ultrasonic impedance damage detection using piezoelectric transducers integrated into fasteners themselves to penetrate into complex joints, thus making it easier to discover hidden damage.