Hybrid State-Detection System for Gearbox Components

Aerospace structures are subject to dynamic loading. In particular, gearbox components experience continuous cyclic loading, wear and eventually develop fatigue cracks. As opposed to most other aircraft components, gearbox components are non-redundant, so a failure can have catastrophic consequences. Gearbox members are typically magnesium, aluminum or high-strength steel that exhibit high fracture toughness, but are brittle, making them susceptible to fatigue failure. Gearbox safety can be ensured via real-time detection methods. Current monitoring systems fail to detect damage in at early enough stage to provide sufficient warning before failure, or may cause false positives. Accurate diagnosis and prognosis of gearbox health state can reduce maintenance schedules, and component life may be extended, which lead to significant life-cycle cost reduction. This proposal focuses on the development of a gearbox PHM system for early detection of cracking. The system will be hybrid in nature, relying on both passive acquisition of elastic waves in operation, as well as active excitation of guided waves while on the ground. Both techniques will make use of model-augmented pattern recognition techniques to characterize an accurate real-time state of health for the gearbox. Metis Design Corporation (MDC) will work closely with collaborator University of Illinois at Chicago (UIC).