Advanced Ferroelectric MFC Actuators: The Effect of Ferro-Elastic Domain Switching

2008 ◽  
Author(s):  
Uri Kushnir ◽  
Oded Rabinovitch
Keyword(s):  
Nonlinear Response ◽  
Domain Switching ◽  
Mechanical Load ◽  
Fiber Composite ◽  
Beam Element ◽  
Mechanical Loads ◽  
Active Structure ◽  
Elastic Domain ◽  
Macro Fiber Composite ◽  
Fiber Segment

Macro Fiber Composite (MFC) actuators, which are commonly integrated in modern smart structures, may be subjected to high levels of mechanical loads. Opposed to the electrical actuation, these loads are not always controlled or anticipated by the user. Thus, they may yield a response that is beyond the linear range due to a stress induced ferro-elastic domain switching. In this paper, the phenomenon of domain switching and mechanical depolarization in the MFC actuator and the resulting degradation of the actuation capabilities are investigated. As an illustrative numerical example, the response of MFC layers in an active beam element is analyzed. Emphasis is placed on the location of the fiber segment along the active beam with a distinction between the compressed and the tensed layers. The results highlight the range of effects associated with the potential nonlinear response of the active structure under high levels of mechanical load.

On the Actuation Authority of Adaptive Sandwich Beam with Composite Actuators: Coupled Finite Element Analysis

2012 ◽  
Vol 585 ◽  
pp. 332-336 ◽  
Author(s):  
K. Venkata Rao ◽  
S. Raja ◽  
T. Munikenche Gowda
Keyword(s):  
Numerical Experiments ◽  
Volume Fraction ◽  
Fiber Composite ◽  
Sandwich Beam ◽  
Beam Theory ◽  
Beam Element ◽  
Fiber Volume ◽  
Element Analysis ◽  
Active Fiber ◽  
Macro Fiber Composite

A two noded active sandwich beam element is formulated by employing layerwise Timoshenko’s beam theory. Displacement continuity conditions are imposed between different layers of the sandwich. This element is used to model an adaptive sandwich beam with macro-fiber composite (MFC) as extension actuator and shear actuated fiber composite (SAFC) as shear actuator. Influence of thickness and volume fraction of the active fiber (PZT-5A and single crystal PMN-PT) in the composite actuators on the actuation performance of the sandwich beam is investigated. Based on several numerical experiments, it is found that the PMN-PT based shear actuators give maximum actuation authority for the volume fraction of the fibers in the range of 80%-85%, whereas in case of PZT-5A based shear actuators the actuation authority remains maximum for the fiber volume fractions 80% and above.

Nonlinear Response of the Macro Fiber Composite Actuator to Monotonically Increasing Excitation Voltages

Aerospace ◽  
2004 ◽  
Author(s):  
R. Brett Williams ◽  
Daniel J. Inman ◽  
W. Keats Wilkie
Keyword(s):  
Mechanical Response ◽  
Mechanical Load ◽  
Fiber Composite ◽  
Second Order ◽  
Nonlinear Material ◽  
External Loading ◽  
Large Set ◽  
Dc Offset ◽  
Linear Elastic ◽  
Macro Fiber Composite

This paper presents a nonlinear model which predicts the response of a piezoelectric continuum to a monotonic increase in electric field from some DC offset value under some constant mechanical load within the linear-elastic region. A general model is derived and then specialized for a piezoceramic-based material with anisotropic actuation and mechanical properties, for example, the Macro Fiber Composite (MFC) actuator. This specialized formulation includes the linear-elastic mechanical response, as well as linear and second-order piezoelectric behavior and a second-order electromechanical cross term. Thus, there are many required linear and nonlinear material parameters, namely the elastic compliances, piezoelectric strain coefficients, electrostrictive, and elastostrictive coefficients. Using previously published work dealing with the mechanical response of the MFC [1], this rather large set of material properties is determined experimentally in order to predict the response of the Macro Fiber Composite device to given external loading conditions.

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

Analysis of Wrinkled Membranes Bounded With Macro-Fiber Composite (MFC) Actuators

2010 ◽  
Author(s):  
Alireza Doosthoseini ◽  
Armaghan Salehian ◽  
Matthew Daly
Keyword(s):  
Finite Element ◽  
Fiber Composite ◽  
The Other ◽  
Horizontal Direction ◽  
Finite Element Code ◽  
Rectangular Shape ◽  
Macro Fiber Composite

In this paper we focus on a study which involves quantifying the effects of Macro Fiber Composite (MFC) actuators on the pattern and magnitude of wrinkles in a membrane when exposed to various loadings. An ABAQUS finite element code is employed for this research. The membrane in this study has a rectangular shape which is clamped at one edge and is free to move in the horizontal direction at the other edge. MFC actuators are bounded to the membrane to make a bimorph configuration.

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