METIS DESIGN CORPORATION — Department of Defense STTR Phase II: N12A-T007

Description

This STTR aims to develop a novel method for detecting and tracking growth of cracks in rotorcraft gearbox. 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. Gearbox safety can be ensured via real-time detection methods. Accurate diagnosis and prognosis of gearbox health state can reduce maintenance schedules, and component life may be extended, which lead to significant cost reduction. This program focuses on the development of a gearbox PHM system for early crack detection. The system is hybrid in nature, relying on signal processing of passively acquired acoustic energy, however in this case the wave energy is in response to an embedded ultrasonic array. In this way, measurements can be taken on the ground without the vehicle in operation, and without a costly disassembly. Model-augmented pattern recognition techniques are used to characterize an accurate real-time state of health for the gearbox.