Electricity-structure-fluid coupled modelling and experiment of underwater flexible structure with partially distributed macro fiber composites

2020 ◽  
pp. 107754632097691
Author(s):  
Junqiang Lou ◽  
Tehuan Chen ◽  
Yiling Yang ◽  
Chao Xu ◽  
Hairong Chen ◽  
...  
Keyword(s):  
Mode Shape ◽  
Fiber Composite ◽  
Coupled Model ◽  
Experimental Results ◽  
Dynamic Responses ◽  
Flexible Structure ◽  
Flexible Beam ◽  
Coupled Modelling ◽  
Hydrodynamic Damping ◽  
Macro Fiber Composite

Dynamic oscillating behavior of the flexible structure immerged in viscous fluids has attracted growing attention and been widely used in various practical applications. A general electricity-structure-fluid coupled model for the forced dynamic responses of a cantilever immersed in fluids, with partially distributed macro fiber composite, is proposed in this paper. Based on the classical Euler–Bernoulli beam theory, the first mass-normalized mode shape of the cantilever with partially bonded macro fiber composite is determined using assumed mode method. The attachment of the macro fiber composite actuators stiffens the macro fiber composite-bonded portion of the cantilever. The established mode shape matches perfectly with experimental results. Considering the macro fiber composite actuator as a set of representative elements connected in parallel, the internally actuation moment provided by the macro fiber composite actuators is obtained. The hydrodynamic load caused by the surrounding fluids, decomposed into the added mass and hydrodynamic damping parts, is also added to the theoretical model in the frequency-domain form. The predicted in-air and underwater dynamic behaviors of the flexible beam are consistent with the experimental results at different auction levels. Thus, the obtained general electricity-structure-fluid coupled model can be used to predict the forced dynamic responses of flexible structure with partially bonded actuators immersed in fluids.

scholarly journals Development of High-Performance Soft Robotic Fish by Numerical Coupling Analysis

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Wenjing Zhao ◽  
Aiguo Ming ◽  
Makoto Shimojo
Keyword(s):  
High Performance ◽  
Fiber Composite ◽  
Swimming Performance ◽  
Structural Parameters ◽  
Robotic Fish ◽  
Dynamic Responses ◽  
Flexible Structure ◽  
Swimming Velocity ◽  
Coupling Analysis ◽  
And Control

To design a soft robotic fish with high performance by a biomimetic method, we are developing a soft robotic fish using piezoelectric fiber composite (PFC) as a flexible actuator. Compared with the conventional rigid robotic fish, the design and control of a soft robotic fish are difficult due to large deformation of flexible structure and complicated coupling dynamics with fluid. That is why the design and control method of soft robotic fish have not been established and they motivate us to make a further study by considering the interaction between flexible structure and surrounding fluid. In this paper, acoustic fluid-structural coupling analysis is applied to consider the fluid effect and predict the dynamic responses of soft robotic fish in the fluid. Basic governing equations of soft robotic fish in the fluid are firstly described. The numerical coupling analysis is then carried out based on different structural parameters of soft robotic fish. Through the numerical analysis, a new soft robotic fish is finally designed, and experimental evaluation is performed. It is confirmed that the larger swimming velocity and better fish-like swimming performance are obtained from the new soft robotic fish. The new soft robotic fish is developed successfully for high performance.

Smart materials applied in a micro remotely piloted aircraft system with morphing wing

2018 ◽  
Vol 29 (16) ◽  
pp. 3317-3332 ◽  
Author(s):  
Miguel A Barcala-Montejano ◽  
Ángel A Rodríguez-Sevillano ◽  
Rafael Bardera-Mora ◽  
Jaime García-Ramírez ◽  
Joaquín de Nova-Trigueros ◽  
...  
Keyword(s):  
Smart Materials ◽  
Fiber Composite ◽  
Experimental Results ◽  
Morphing Wing ◽  
Computational Calculations ◽  
Remotely Piloted Aircraft ◽  
Adaptive Wing ◽  
Wing Geometry ◽  
Macro Fiber Composite ◽  
Aircraft System

The article presents a research in the field of morphing wings (adaptive wing geometry) developed over a prototype of micro-unmanned air vehicle based on smart materials technology. This morphing wing will optimize the aircraft performance features. Modifying the curvature of the wing, the micro-unmanned air vehicles will adjust its performance in an optimum mode to cruise flight condition as well as in the phases of takeoff and landing. The installation of mechanical elements for control surfaces in small size aircraft means, on some occasions, an extra complexity. In addition, it takes into account an increase in aircraft weight. In this research, the adaptive wing geometry is based on macro-fiber composites, so that its position on the inner surfaces of the wing allows the appropriate modification of the curvature, adapting them to the flight profile. This research will present the conceptual design of the vehicle, computational calculations, experimental results of the wind tunnel testing, validations using non-intrusive techniques (particle image velocimetry) and a theoretical–experimental analysis of the macro-fiber composite effects over the wing. An Arduino board will perform the control parameters of the macro-fiber composite deformation. With these analytical, computational, and experimental results, the most relevant conclusions are presented.

Theoretical and Experimental Investigation on Modal Characteristics of Rotating Flexible Beam under Dynamic Boundary Conditions

2014 ◽  
Vol 518 ◽  
pp. 33-40
Author(s):  
Hai Bin Yin ◽  
Yu Feng Li ◽  
Yan Zhao ◽  
Pei Juan Cui
Keyword(s):  
Boundary Conditions ◽  
Mode Shape ◽  
Flexible Structure ◽  
Flexible Beam ◽  
Beam Model ◽  
Shape Functions ◽  
Dynamic Boundary Conditions ◽  
Modal Characteristics ◽  
Dynamic Boundary ◽  
Free Beam

In order to exactly formulate the dynamics and solve the flexible vibration in the studies on the flexible structure, it is inevitable to study the modal characteristics of the flexible structure; while the accuracy of the modal characteristics relies on the choice of its boundary conditions. This paper investigates the modal characteristics of a flexible beam considering dynamic boundary conditions. Firstly, the first three mode shape functions and frequencies of a sliding-mass beam model are obtained through theoretical solutions. The concept of dynamic boundary conditions is brought forward by the study of special boundary conditions. Secondly, a rotating-free beam model is proposed to describe the dynamic boundary conditions of the rotating flexible beam. The first three frequencies and the mode shape functions of the rotating-free beam model are obtained. Finally, a series of samples and experiments proves the validity of the proposal on the rotating-free beam model.

Unbalance Response of a Dual Rotor System: Theory and Experiment

1993 ◽  
Vol 115 (4) ◽  
pp. 427-435 ◽  
Author(s):  
K. Gupta ◽  
K. D. Gupta ◽  
K. Athre
Keyword(s):  
System Theory ◽  
Transfer Matrix ◽  
Mode Shape ◽  
Reasonable Agreement ◽  
Complex Variables ◽  
Rotor System ◽  
Experimental Results ◽  
Unbalance Response ◽  
Theoretical Results ◽  
Theory And Experiment

A dual rotor rig is developed and is briefly discussed. The rig is capable of simulating dynamically the two spool aeroengine, though it does not physically resemble the actual aeroengine configuration. Critical speeds, mode shape, and unbalance response are determined experimentally. An extended transfer matrix procedure in complex variables is developed for obtaining unbalance response of dual rotor system. Experimental results obtained are compared with theoretical results and are found to be in reasonable agreement.

Macro-Fiber Composite Actuators for Flow Control of a Variable Camber Airfoil

2010 ◽  
Vol 22 (1) ◽  
pp. 81-91 ◽  
Author(s):  
Onur Bilgen ◽  
Carlos De Marqui ◽  
Kevin B. Kochersberger ◽  
Daniel J. Inman
Keyword(s):  
Flow Control ◽  
Fiber Composite ◽  
Macro Fiber Composite
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