Analytical and Experimental Characterization of Macro-Fiber Composite Actuated Thin Clamped-Free Unimorph Benders

2010 ◽  
Vol 132 (5) ◽  
Author(s):  
Onur Bilgen ◽  
Alper Erturk ◽  
Daniel J. Inman
Keyword(s):  
Fiber Composite ◽  
Steel Substrate ◽  
Actuation Voltage ◽  
Structural Response ◽  
Distributed Parameter ◽  
Experimental Characterization ◽  
Macro Fiber Composite ◽  
Cantilevered Beams ◽  
Tip Velocity

A type of piezoceramic composite actuator known as Macro-Fiber Composite (MFC) is used commonly for actuation in smart-material structures. In this paper, a linear distributed parameter electromechanical model is proposed to predict the structural response to MFC actuated clamped-free thin cantilevered beams. The structural frequency response behavior between the tip velocity of the cantilever beam and the actuation voltage of the piezoelectric material is investigated experimentally for cantilevered unimorph MFC actuated benders with aluminum, brass, and steel substrate materials with different thicknesses. Good correlation is observed between the model and the experimental observations.

Underwater Dynamic Actuation of Macro-Fiber Composite Flaps With Different Aspect Ratios: Electrohydroelastic Modeling, Testing, and Characterization

2014 ◽  
Author(s):  
Shima Shahab ◽  
Alper Erturk
Keyword(s):  
Electromechanical Coupling ◽  
Fiber Composite ◽  
Actuation Voltage ◽  
Metal Composite ◽  
Actuation Frequency ◽  
Aspect Ratios ◽  
Current Consumption ◽  
Macro Fiber Composite ◽  
Tip Velocity ◽  
Hydrodynamic Function

Macro-fiber composite (MFC) actuators offer simple and scalable design, robustness, noiseless performance, strong electromechanical coupling, and particularly a balance between the actuation force and deformation capabilities, which is essential to effective and agile biomimetic locomotion. Recent efforts in our lab have shown that MFC bimorphs with polyester electrode sheets can successfully be employed for fish-like aquatic locomotion in both tethered and untethered operation. MFC swimmers can outperform other smart material-based counterparts, such as the compliant ionic polymer-metal composite based swimmers, in terms of swimming speed per body length. Cantilevered flaps made of MFC bimorphs with different aspect ratios can be employed for underwater actuation, sensing, and power generation, among other aquatic applications of direct and converse piezoelectric effects. In an effort to develop linearized electrohydroelastic models for such cantilevers, the present work investigates MFC bimorphs with three different aspect ratios. The MFCs used in this study use the 33-mode of piezoelectricity with interdigitated electrodes. Underwater dynamic actuation frequency response functions (FRFs) of the MFCs are defined as the tip velocity per actuation voltage (tip velocity FRF) and current consumption per actuation voltage (admittance FRF). The tip velocity and admittance FRFs are modeled analytically for in-air actuation and validated experimentally for all aspect ratios. Underwater tip velocity and admittance FRFs are then derived by combining their in-air counterparts with corrected hydrodynamic functions. The corrected hydrodynamic functions are also identified from aluminum cantilevers of similar aspect ratios. Both tip vibration and current consumption per voltage input are explored. The failure of Sader’s hydrodynamic function for low length-to-width aspect ratios is shown. Very good correlation is observed between model simulations and experimental measurements using aspect ratio-dependent, corrected hydrodynamic function.

Characterization of Piezoelectric Macrofiber Composite Actuated Winglets

2014 ◽  
Author(s):  
Tufan Kumar Guha ◽  
William Oates ◽  
Rajan Kumar
Keyword(s):  
Fiber Composite ◽  
Pressure Measurements ◽  
Pressure Loading ◽  
Tip Vortices ◽  
Resonance Behavior ◽  
Pressure Distributions ◽  
Point Pressure ◽  
Macro Fiber Composite ◽  
Wing Tip

Piezoelectric macro-fiber composite (MFC) structures have been used to develop oscillating winglets for active control of wing-tip vortices. A MFC structure was embedded inside a wing-section to oscillate the winglet at its free end. The goal is to weaken the potentially harmful tip vortices by introducing controlled instabilities through both spatial and temporal perturbations produced by an oscillating winglet. In the present study we have characterized MFC actuated winglets under different input excitation and pressure loading conditions. It consisted of bench-top experiments to characterize the structural resonance, with and without point pressure loading and wind tunnel tests involving distributed pressure loading. Surface pressure measurements were carried out at three spanwise locations to measure the effect of oscillating winglet on the pressure distributions on the wing surface. MFC actuated winglets show bimodal resonance behavior and the modes of oscillations are independent of magnitude of input excitation and the pressure loading.

Fatigue Characterization of Piezo-Active Beams in Bending

2017 ◽  
Author(s):  
Jonathan D. Degroff ◽  
Onur Bilgen
Keyword(s):  
Plate Theory ◽  
Fiber Composite ◽  
Steel Substrate ◽  
Laminate Plate ◽  
Excitation Amplitude ◽  
Harmonic Excitation ◽  
Highly Sensitive ◽  
Classical Laminate Plate Theory ◽  
Bending Response

This paper presents the fatigue characterization of piezo-active beams in bending with surface bonded Macro-Fiber Composite actuators. Three substrate materials are considered: stainless steel, aluminum, and brass. First, the bending response is quantified theoretically using the classical laminate plate theory. The theoretical bending results indicate that the beam with the steel substrate had the largest curvature, and the specimen with the aluminum had the least. Next, midpoint deflection in a simply supported configuration in response to harmonic quasi-static actuation is experimentally measured. The results from the experiments showed no evidence of degradation of actuation for up to four million cycles at the harmonic excitation amplitude of 500 V; however, the results appeared highly sensitive to temperature.

Parametric Analysis of Structural Properties of a Rectangular Partially-Clamped Wing

2020 ◽  
Author(s):  
Mohammad Katibeh ◽  
Onur Bilgen
Keyword(s):  
Parametric Analysis ◽  
Piezoelectric Materials ◽  
Fiber Composite ◽  
Structural Response ◽  
Critical System ◽  
Resonant Frequencies ◽  
System Parameters ◽  
Composite Substrate ◽  
Macro Fiber Composite ◽  
Actuation Systems

Abstract The so-called solid-state ornithopter concept seeks to employ piezoelectric materials to generate flapping motion instead of relying on conventional mechanisms and multi-component actuation systems. The motion can be induced on a wing-like partially-clamped composite substrate with a piezocomposite device (i.e. the Macro-Fiber Composite actuator.) In this research, a design for a flapping wing is proposed based on the analysis of critical system parameters such as geometric properties and boundary conditions. A series of finite element simulations are conducted based on the variation of those parameters. Consequently, the effects of parameters on the structural response is studied. Also, modal analysis is done to examine the effects of geometric parameters on the resonant frequencies of the system. Heaving and pitching responses are examined.

Manufacturing and Mechanics-Based Characterization of Macro Fiber Composite Actuators

2002 ◽  
Author(s):  
R. Brett Williams ◽  
Brian W. Grimsley ◽  
Daniel J. Inman ◽  
W. Keats Wilkie
Keyword(s):  
Lead Zirconate Titanate ◽  
Structural Design ◽  
Fiber Composite ◽  
Cure Kinetics ◽  
Ceramic Materials ◽  
Lead Zirconate ◽  
Linear Elastic ◽  
Lamination Theory ◽  
Macro Fiber Composite

The use of piezoelectric ceramic materials for structural actuation is a fairly well developed practice that has found use in a wide variety of applications. However, just as advanced composites offer many benefits over traditional engineering materials for structural design, actuators that utilize the active properties of piezoelectric fibers can improve upon many of the limitations encountered with monolithic piezoceramic devices used to control structural dynamics. This paper discusses the Macro Fiber Composite (MFC) actuator, which utilizes piezoceramic fibers, for example, lead zirconate titanate (PZT), embedded in an epoxy matrix for structural actuation. An overview of the MFC assembly process is presented, followed by a cure kinetics model that describes the behavior of the thermosetting matrix. This empirical model is seen to agree closely with the experimental data. Lastly, a hybrid classical lamination theory is developed to predict the linear elastic properties of the MFC package as a function of the PZT fiber lamination angle.

Experimental characterization of FRP composite-wood pile structural response by bending tests

2003 ◽  
Vol 16 (4) ◽  
pp. 257-274 ◽  
Author(s):  
Roberto Lopez-Anido ◽  
Antonis P. Michael ◽  
Thomas C. Sandford
Keyword(s):  
Structural Response ◽  
Experimental Characterization ◽  
Bending Tests ◽  
Frp Composite ◽  
Composite Wood
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