Experimental Demonstration of a Vibration Absorber Using Braid-Sheathed Fluidic Flexible Matrix Composite Tubes

2019 ◽  
Vol 64 (3) ◽  
pp. 1-6
Author(s):  
Kentaro Miura ◽  
Matthew J. Krott ◽  
Edward C. Smith ◽  
Christopher D. Rahn ◽  
Peter Q. Romano
Keyword(s):  
Matrix Composite ◽  
Vibration Absorber ◽  
Experimental Demonstration ◽  
Experimental Frequency ◽  
Low Profile ◽  
Bending Mode ◽  
Model Predictions ◽  
Flow Through ◽  
Flexible Matrix Composite ◽  
Tuned Vibration Absorber

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.

Coupled and Multimode Tailboom Vibration Control Using Fluidic Flexible Matrix Composite Tubes

2019 ◽  
Vol 64 (4) ◽  
pp. 1-10
Author(s):  
Matthew J. Krott ◽  
Edward C. Smith ◽  
Christopher D. Rahn
Keyword(s):  
Vibration Control ◽  
Matrix Composite ◽  
Structural Model ◽  
Vibration Absorber ◽  
Vibration Modes ◽  
Lateral Bending ◽  
Vertical Mode ◽  
Torsion Mode ◽  
Vertical Vibrations ◽  
Flexible Matrix Composite

This paper covers the modeling and testing of a helicopter tailboom integrated with a fluidic flexible matrix composite (F2MC) damped vibration absorber. In an advance over previous work, the F2MC absorber presented in this paper treats a combination of tailboom lateral, torsional, and vertical vibrations. A finite element structural model of a laboratory-scale tailboom is combined with a model of attached F2MC tubes and a tuned fluidic circuit. Vibration reductions of over 75% in a coupled 26.8-Hz lateral bending/torsion tailboom mode are predicted by the model and measured experimentally. These results demonstrate that F2MC vibration control is viable at higher frequencies and for more complex vibration modes than previous research had explored. A new absorber with a fluidic circuit that targets two tailboom vibration modes is designed and experimentally tested. On the lab-scale tailboom testbed, the absorber with this circuit is shown to provide vibration reductions of over 60% in both a 12.2-Hz vertical mode and a 26.8-Hz lateral bending/torsion mode. Using this new absorber, vertical and lateral/torsion mode damping are achieved with almost no added weight relative to a purely vertical absorber.

Modeling and Testing of Fluidic Flexible Matrix Composite Lead–Lag Dampers

2020 ◽  
Vol 65 (1) ◽  
pp. 1-10
Author(s):  
Matthew J. Krott ◽  
Edward C. Smith ◽  
Christopher D. Rahn
Keyword(s):  
Frequency Response ◽  
Matrix Composite ◽  
Rotor Blade ◽  
System Model ◽  
Response Data ◽  
Model Predictions ◽  
Simulation Results ◽  
Flexible Matrix Composite ◽  
Hydraulic Accumulator ◽  
Lag Dampers

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 Vibration Absorber for a Cantilever Beam

2015 ◽  
Vol 137 (2) ◽  
Author(s):  
Bin Zhu ◽  
Christopher D. Rahn ◽  
Charles E. Bakis
Keyword(s):  
Cantilever Beam ◽  
Matrix Composite ◽  
Volume Change ◽  
Experimental Testing ◽  
Axial Strain ◽  
Flexible Structures ◽  
Resonant Peak ◽  
Track Length ◽  
Vibration Absorber ◽  
Flexible Matrix Composite

Fluidic flexible matrix composite (F2MC) tubes with resonant fluidic circuits can absorb vibration at a specific frequency when bonded to flexible structures. The transverse structural vibration applies cyclic axial strain to the F2MC tubes. The anisotropic elastic properties of the composite tube amplify the axial strain to produce large internal volume change. The volume change forces fluid through a flow port and into an external accumulator. The fluid inertance in the flow port (inertia track) and the stiffness of the accumulator are analogous to the vibration absorbing mass and stiffness in a conventional tuned vibration absorber. An analytical model of an F2MC-integrated cantilever beam is developed based on Euler–Bernoulli beam theory and Lekhnitskii's solution for anisotropic layered tubes. The collocated tip force to tip displacement analytical transfer function of the coupled system is derived. Experimental testing is conducted on a laboratory-scale F2MC beam structure that uses miniature tubes and fluidic components. The resonant peak becomes an absorber notch in the frequency response function (FRF) if the inertia track length is properly tuned. Tuning the fluid bulk modulus and total flow resistance in the theoretical model produces results that match the experiment well, predicting a magnitude reduction of 35 dB at the first resonance using an F2MC absorber. Based on the experimentally validated model, analysis results show that the cantilever beam vibration can be reduced by more than 99% with optimally designed tube attachment points and flow port geometry.

Tunable Vibration Absorption of a Cantilever Beam Utilizing Fluidic Flexible Matrix Composites

2013 ◽  
Author(s):  
Bin Zhu ◽  
Christopher D. Rahn ◽  
Charles E. Bakis
Keyword(s):  
Cantilever Beam ◽  
Beam Theory ◽  
Vibration Absorber ◽  
Matrix Composites ◽  
Fluid Inertia ◽  
Vibration Absorption ◽  
Flexible Matrix Composite ◽  
Euler Bernoulli Beam ◽  
Tuned Vibration Absorber ◽  
Beam Transverse Vibration

Bonding a fluidic flexible matrix composite (F2MC) tube to a cantilever beam can create a lightly damped tuned vibration absorber. The beam transverse vibration couples with the F2MC tube strain to generate flow into an external accumulator via a flow port. The fluid inertia is analogous to the vibration absorbing mass in a conventional tuned vibration absorber. The large F2MC tube pressure accelerates the fluid so that the developed inertia forces cancel most of the vibration loads. An analytical model is developed based on Euler-Bernoulli beam theory and Lekhnitskii’s solution for anisotropic layered tubes. The analysis results show that the cantilever beam vibration can be reduced by more than 99% by designing the F2MC fiber angle, the tube attachment points, and the flow port geometry.

Vibration Isolation of a Cantilever Beam Using Fluidic Flexible Matrix Composite Tubes

2015 ◽  
Author(s):  
Kentaro Miura ◽  
Bin Zhu ◽  
Christopher D. Rahn ◽  
Edward C. Smith ◽  
Charles E. Bakis
Keyword(s):  
Cantilever Beam ◽  
Matrix Composite ◽  
Vibration Isolation ◽  
Low Weight ◽  
Bending Mode ◽  
Pumping Efficiency ◽  
Transmission Attenuation ◽  
Beam Surface ◽  
Beam Bending ◽  
Flexible Matrix Composite

Fluidic Flexible Matrix Composite (F2MC) tubes are a new class of high-authority and low-weight fluidic devices that can passively provide vibration damping, absorption, and isolation. In this paper, transverse cantilever beam vibration causes strain-induced fluid pumping in F2MC tubes bonded to the beam surface, generating flow through a fluidic circuit. The F2MC tubes and fluidic circuit are designed to significantly reduce moment and shear transmission at the root of the cantilever beam. An analytical model of a cantilever beam with F2MC tubes is used to perform a parametric study via Monte Carlo methods. An isolator is designed that simultaneously attenuates root shear and moment transmission by over 99% at the first bending mode. By modifying the fluidic circuit dimensions and F2MC tube attachment locations, over 99% root shear and moment transmission attenuation is achieved for the second beam bending mode. The tunability and pumping efficiency of the F2MC tube makes it a promising candidate for passive vibration control applications, including aerospace structures such as wings and rotorcraft landing gear.

scholarly journals Hydrogel core flexible matrix composite (H-FMC) actuators: theory and preliminary modelling

2014 ◽  
Vol 23 (9) ◽  
pp. 095021 ◽  
Author(s):  
M P M Dicker ◽  
P M Weaver ◽  
J M Rossiter ◽  
I P Bond
Keyword(s):  
Matrix Composite ◽  
Flexible Matrix Composite

scholarly journals Development of an MRE adaptive tuned vibration absorber with self-sensing capability

2015 ◽  
Vol 24 (9) ◽  
pp. 095012 ◽  
Author(s):  
Shuaishuai Sun ◽  
Jian Yang ◽  
Weihua Li ◽  
Huaxia Deng ◽  
Haiping Du ◽  
...  
Keyword(s):  
Vibration Absorber ◽  
Tuned Vibration Absorber

Vibration control using a beam-like adaptive tuned vibration absorber with an actuator-incorporated mass element

2009 ◽  
Vol 223 (7) ◽  
pp. 1555-1567 ◽  
Author(s):  
P Bonello ◽  
K H Groves
Keyword(s):  
Vibration Control ◽  
Effective Mass ◽  
Tuning Range ◽  
Excitation Frequency ◽  
Vibration Absorber ◽  
Time Varying ◽  
Additional Advantage ◽  
Expected Performance ◽  
Vibration Attenuation ◽  
Tuned Vibration Absorber

An adaptive tuned vibration absorber (ATVA) can retune itself in response to a time-varying excitation frequency, enabling effective vibration attenuation over a range of frequencies. For a wide tuning range the ATVA is best realized through the use of a beam-like structure whose mechanical properties can be adapted through servo-actuation. This is readily achieved either by repositioning the beam supports (‘moveable-supports ATVA’) or by repositioning attached masses (‘moveable-masses ATVA’), with the former design being more commonly used, despite its relative constructional complexity. No research to date has addressed the fact that the effective mass of such devices varies as they are retuned, thereby causing a variation in their attenuation capacity. This article derives both the tuned frequency and effective mass characteristics of such ATVAs through a unified non-dimensional modal-based analysis that enables the designer to quantify the expected performance for any given application. The analysis reveals that the moveable-masses concept offers significantly superior vibration attenuation. Motivated by this analysis, a novel ATVA with actuator-incorporated moveable masses is proposed, which has the additional advantage of constructional simplicity. Experimental results from a demonstrator correlate reasonably well with the theory, and vibration control tests with logic-based feedback control demonstrate the efficacy of the device.

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