Fluidic flexible matrix composite (F2MC) tubes are a novel type of lightweight, low-profile passive fluidic vibration treatments for structures. Two pairs of F2MC tubes are installed onto a laboratory-scale helicopter tailboom structure and interconnected through a fluidic circuit, resulting in a tuned vibration absorber. The experimental frequency response of the absorber-treated tailboom shows a response amplitude reduction of over 70% for the first vertical bending mode. By partially restricting flow through an orifice in the fluidic circuit, a damped absorber is achieved that adds nearly 8% damping to the first vertical bending mode. The effect of fluid prepressure and tailboom forcing amplitude are also studied. The experimental results show excellent agreement with model predictions.

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A new lead–lag damper concept using a fluidic flexible matrix composite (F2MC) tube is presented in this paper. A model is developed for an articulated rotor blade integrated with an F2MC damper consisting of an F2MC tube, an inertia track, an orifice, and a hydraulic accumulator. Benchtop tests using a 4.5-ft rotor blade demonstrate the performance of a smallscale F2MC damper. The blade–damper system model predictions are verified by comparing experimentally measured and model-predicted frequency response data. In benchtop tests, the model predicts blade damping ratios of up to 0.34 with the F2MC damper. A simplified articulated blade based on the UH-60 rotor is simulated to assess the feasibility of a full-scale F2MC damper. Simulation results predict that the damper can generate blade damping ratios of over 0.30 at low blade lag angles.

Fluidic flexible matrix composite (F2MC) tubes can add damping to and absorb vibrations from a host structure. Transverse structural vibration couples with F2MC tube strain to pump fluid through an external circuit that can be tailored to provide vibration damping and/or absorption. In this paper, an F2MC-cantilever system, consisting of two F2MC tubes attached to a uniform cantilever beam, is designed, fabricated, and experimentally tested. The F2MC tubes are connected in parallel to one of two fluidic circuits. The first circuit uses an orifice to dissipate energy, reducing the first mode resonant response by over 20 dB and providing 5% damping. The second circuit uses an inertia track and an accumulator to produce a tuned absorber that replaces the first mode resonance peak with a valley, reducing the resonant response by 27 dB.