Recent studies demonstrate that a key advantage of flexible matrix composite (FMC) shaft technology is the ability to accommodate misalignments without need for segmenting or flexible couplings as required by conventional alloy and graphite/epoxy composite shafts. While this is indeed a very promising technology for rotorcraft driveshafts, the high-damping loss-factor, and thermal stiffness and damping sensitivities of the urethane matrix, makes FMC shafting more prone to self-heating and whirl instabilities. Furthermore, the relatively low-bending stiffness and critical speeds of FMC shafts make imbalance vibration a significant challenge to supercritical operation. To address these issues and advance the state of the art, this research explores active magnetic bearing (AMB) technology together with a robust-adaptive hybrid H∞ feedback/synchronous adaptive vibration control law designed to ensure stable supercritical operation of a prototype FMC rotorcraft driveline. The effectiveness of the proposed new approach is demonstrated through analysis of a helicopter driveline testbed.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Aerospace Engineering
- Mechanics of Materials
- Mechanical Engineering