15:30 - 17:30 | Mon 19 Aug | Lau, 6-209 | MoC2
This paper describes research on the active control of vibration in thin-walled cylindrical structures under rotation. Enhanced damping of flexural vibration may be achieved through feedback control of embedded piezoelectric patch actuators. To assess the interaction of wall vibration with actuator and sensor operation, a theoretical model of a rotating annulus is considered. This model describes the multi-mode travelling wave behavior for circumferential vibration. It is seen that, due to rotational symmetry, use of only a single actuator will lead to one of each pair of degenerate modes being uncontrollable in the non-rotating case. However, as rotational speed increases, full controllability is recovered. This is due to the transition under rotation from standing mode to travelling wave characteristics for the vibration. Experiments were conducted on a short thin-walled steel cylinder (diameter 224 mm). A collocated actuator/sensor (piezoelectric patch) pair was applied with a control law based on resonant filters to achieve enhanced damping of circumferential vibration modes up to third order (natural frequencies: 161, 443, 846 Hz). A second actuator/sensor pair was used to assess controllability and the effectiveness of the active damping control loop. The results confirm the suitability of the theoretical models and qualitative predictions of the speed-dependent control influence for the actuator/sensor pairs.
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