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

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.

2019 ◽  
Vol 64 (3) ◽  
pp. 1-6
Author(s):  
Kentaro Miura ◽  
Matthew J. Krott ◽  
Edward C. Smith ◽  
Christopher D. Rahn ◽  
Peter Q. Romano

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.


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

2011 ◽  
Vol 189-193 ◽  
pp. 2535-2538 ◽  
Author(s):  
Hong Yan ◽  
Wen Xian Huang

The thixo-forging of magnesium matrix composite was analyzed with computer numerical simulation based on rigid viscoplastic finite element method. The constitutive model of SiCp/AZ61 composite was established in our prior literature. Behavior of metal flow and temperature field were obtained. The differences between traditional forging and thixo-forging processes were analyzed. Results indicated that thixo-forging was better in filling cavity than forging. Simulation results were good agreement with experimental ones.


2011 ◽  
Vol 328-330 ◽  
pp. 2108-2112
Author(s):  
Jing Shuang Lu ◽  
Chun Mei Du ◽  
Rui Zhou ◽  
Na Li

A simple dynamics model is established based on the two-link flexible manipulator moving within the vertical plane, and a robust simple control scheme is put forward. The advantages of this scheme are simple and good robustness. Only the error signal is needed when designing the control scheme and the acquirement of control signal does not depend on the system model. The simulation results show that this method has a good robustness and stability.


2013 ◽  
Vol 14 (6) ◽  
pp. 549-559 ◽  
Author(s):  
Krupa Shah ◽  
K. Ragavan

Abstract This article focuses on developing a non-invasive method for determining capacitances using frequency response data. The proposed methodology involves acquiring driving-point impedance of the winding under consideration over wide frequency range. With certain terminal conditions and using the terminal impedance measured at specific frequencies, input and shunt capacitances are determined. For the purpose of estimating series capacitance of the winding, an algorithm is proposed. To demonstrate the capability of the method, initially model coils that have provisions for connecting external capacitances are considered. Then, it is found that the estimated values of capacitances are nearly same as those of connected capacitances. The method is, then, extended to transformer winding, and a capacitive ladder network is constructed. To assess the accuracy of estimation, capacitive voltage distribution is utilized. That is, the voltage distribution in the winding is compared with that of synthesized circuit. A good agreement between those data reveals that the estimated capacitance values are accurate.


2011 ◽  
Vol 317-319 ◽  
pp. 672-677
Author(s):  
Bin Wei ◽  
Ji Bin Hu ◽  
Zeng Xiong Peng

A novel vector control system of the split double-rotor motor based on indirect vector control principle has been proposed. The mathematic models of the primary machine and the secondary machine are set up respectively. Through the coupling of the two models, the system model of the split double-rotor motor is build. Matlab software is used for the simulation and analysis of this indirect vector control system. According to the simulation results, the validity of system model is proved with nicer static and dynamic capability, and without steady-state error in stable state. These are important to analyze and design the double-rotor motor. Furthermore, the results provide the basis for simulation and apply of double-rotor motor in HEV.


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