scholarly journals Coupling of experimentally validated electroelastic dynamics and mixing rules formulation for macro-fiber composite piezoelectric structures

2016 ◽  
Vol 28 (12) ◽  
pp. 1575-1588 ◽  
Author(s):  
Shima Shahab ◽  
Alper Erturk
Keyword(s):  
Power Generation ◽  
Composite Structures ◽  
Electromechanical Coupling ◽  
Fiber Composite ◽  
Rectangular Cross Section ◽  
Mixing Rules ◽  
Modeling Framework ◽  
Interdigitated Electrodes ◽  
Macro Fiber Composite ◽  
Piezoelectric Structures

Piezoelectric structures have been used in a variety of applications ranging from vibration control and sensing to morphing and energy harvesting. In order to employ the effective 33-mode of piezoelectricity, interdigitated electrodes have been used in the design of macro-fiber composites which employ piezoelectric fibers with rectangular cross section. In this article, we present an investigation of the two-way electroelastic coupling (in the sense of direct and converse piezoelectric effects) in bimorph cantilevers that employ interdigitated electrodes for 33-mode operation. A distributed-parameter electroelastic modeling framework is developed for the elastodynamic scenarios of piezoelectric power generation and dynamic actuation. Mixing rules (i.e. rule of mixtures) formulation is employed to evaluate the equivalent and homogenized properties of macro-fiber composite structures. The electroelastic and dielectric properties of a representative volume element (piezoelectric fiber and epoxy matrix) between two neighboring interdigitated electrodes are then coupled with the global electro-elastodynamics based on the Euler–Bernoulli kinematics accounting for two-way electromechanical coupling. Various macro-fiber composite bimorph cantilevers with different widths are tested for resonant dynamic actuation and power generation with resistive shunt damping. Excellent agreement is reported between the measured electroelastic frequency response and predictions of the analytical framework that bridges the continuum electro-elastodynamics and mixing rules formulation.

Large deformation mechanical modeling with bilinear stiffness for Macro-Fiber Composite bimorph based on extending mixing rules

2020 ◽  
pp. 1045389X2095125
Author(s):  
Kai-ming Hu ◽  
Hua Li
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Large Deformation ◽  
Composite Structures ◽  
Fiber Composite ◽  
Three Dimensional ◽  
Element Model ◽  
Fiber Composites ◽  
Mixing Rules ◽  
Macro Fiber Composite

Macro-Fiber Composite bimorph is a kind of piezoelectric actuator that allow large bending deformation. However, macro-fiber composites exhibit strong stiffness nonlinearity in their operation range, so it is difficult to accurately estimate their large deformation behavior based on a linear constitutive model. In addition, the macro-fiber composites have active and inactive parts, that significantly differ in their material sizes and properties, so it is not reasonable to consider them as uniform material. Thus, it is necessary develop an accurate modeling and analysis method for the large deformation macro-fiber composite structures. First, the mixing rules are extended to derive the three-dimensional homogenized mechanical and electrical parameters of the macro-fiber composite active part; based on these parameters, the actuation results of linear finite element model is in good agreement with the official data. Then a finite element model of the axially compressed macro-fiber composite bimorph is established, the bilinear tensile stiffness of macro-fiber composite is realized by secondary development in ANSYS. Comparison with the experimental results reveals high accuracy of the established finite element model. Thus, the developed method can be effectively used for the performance evaluation and design of the macro-fiber composite devices with large deformation.

Comparative Investigation of the Electroelastic Dynamics of Piezoceramics With Interdigitated and Uniform Electrodes

2012 ◽  
Author(s):  
Martin Cacan ◽  
Alper Erturk
Keyword(s):  
Power Generation ◽  
Electromechanical Coupling ◽  
Fiber Composite ◽  
Electrical Power ◽  
Comparative Investigation ◽  
Distributed Parameter ◽  
Interdigitated Electrodes ◽  
Piezoelectric Effects ◽  
Shunt Damping ◽  
Piezoelectric Bimorphs

Piezoelectric systems and structures have been used for decades in a variety of applications ranging from vibration control and sensing to morphing and energy harvesting. Conventional piezoelectric ceramics with uniform electrodes typically employ the 31-mode of piezoelectricity in bending, where the 3- and 1-directions are the directions of poling and strain, respectively. In order to employ the more effective 33-mode of piezoelectricity, Interdigitated Electrodes (IDEs) have been used recently in the design of the Macro-Fiber Composite (MFC). In this paper, an investigation into the two-way electroelastic coupling in bimorph cantilevers (in the sense of direct and converse piezoelectric effects) that employ IDEs for 33-mode operation is conducted. To this end, distributed-parameter electroelastic models are developed for the dynamic scenarios that involve two-way coupling, namely piezoelectric power generation and shunt damping as well as the problem of dynamic actuation. Various interdigitated MFC bimorph cantilevers are tested against the model under dynamic actuation, power generation, and shunt damping to identify their modal electromechanical coupling terms. Detailed investigations are conducted by decoupling the system dynamics to keep the direct and converse effects separately pronounced for parameter identification. Additionally, this work sheds light on the literature comparing the electrical power generation performances of 33-mode (interdigitated electrodes) and 31-mode (uniform electrodes) piezoelectric bimorphs of the same volume based on extensive experiments and distributed-parameter electroelastic modeling.

Resonant Nonlinearities of Macro-Fiber Composite Cantilevers in Energy Harvesting

2017 ◽  
Author(s):  
David Tan ◽  
Paul Yavarow ◽  
Alper Erturk
Keyword(s):  
Energy Harvesting ◽  
Fiber Composite ◽  
Rectangular Cross Section ◽  
Electrical Power ◽  
Interdigitated Electrodes ◽  
Modeling And Analysis ◽  
Dissipative Effects ◽  
Macro Fiber Composite ◽  
Electrical Loads ◽  
Electrical Power Output

We explore the modeling and analysis of nonlinear non-conservative dynamics of macro-fiber composite (MFC) piezo-electric structures, guided by rigorous experiments, for resonant vibration-based energy harvesting, as well as other applications leveraging the direct piezoelectric effect, such as resonant sensing. The MFCs employ piezoelectric fibers of rectangular cross section embedded in kapton with interdigitated electrodes to exploit the 33-mode of piezoelectricity. Existing frameworks for resonant nonlinearities have so far considered conventional piezoceramics that use the 31-mode of piezoelectricity. In the present work, we develop a framework to represent and predict nonlinear electroelastic dynamics of MFC bimorph cantilevers under resonant base excitation. The interdigitated electrodes are shunted to a set of resistive electrical loads to quantify the electrical power output. Experiments are conducted on a set of MFC bimorphs over a broad range of mechanical excitation levels to identify the types of nonlinearities present and to compare the model predictions and experiments. The experimentally observed interaction of material softening and geometric hardening effects, as well as dissipative effects, is captured and demonstrated by the model.

Piezoelectric energy harvesting using macro fiber composite patches

2020 ◽  
Vol 234 (21) ◽  
pp. 4331-4349
Author(s):  
Marwa Mallouli ◽  
Mnaouar Chouchane
Keyword(s):  
Energy Harvesting ◽  
Epoxy Matrix ◽  
Composite Structures ◽  
Fiber Composite ◽  
Matrix Material ◽  
Interdigitated Electrodes ◽  
Piezoelectric Energy ◽  
Resonance Frequencies ◽  
Macro Fiber Composite ◽  
Tip Mass

Over the last decade, vibration energy harvesting has received substantial attention of many researchers. Piezoelectric materials are able to capture energy from ambient vibration and convert it into electricity which can be stored in batteries or utilized to power small electronic devices. In order to benefit from the 33-mode of the piezoelectric effect, interdigitated electrodes have been utilized in the design of macro fiber composites which are made of piezoelectric fibers of square cross sections embedded into an epoxy matrix material. This paper presents an analytical model of a macro fiber composite bimorph energy harvester using the 33-mode. The mixing rule is applied to determine the equivalent and homogenized properties of the macro fiber composite structures. The electromechanical properties of a representative volume element composed of piezoelectric fibers and an epoxy matrix between two successive interdigitated electrodes are coupled with the overall electro-elastodynamics of the harvester utilizing the Euler–Bernoulli theory. Macro fiber composite bimorph cantilevers with diverse widths are simulated for power generation when a resistive shunt loading is applied. Stress components in the Kapton layers, which are typically a part of any macro fiber composite patch, and in the bonding layers have been included in the model contrary to previously published studies. Variable tip mass, attached at the free end of the beam, is utilized in this paper to tune the resonance frequency of the harvester. The generated power at the fundamental short circuit and open circuit resonance frequencies of harvesters having three different widths is analyzed. It has been observed that higher electrical outputs are produced by the wider macro fiber composite bimorph using (M8528-P1 patches).

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.

Fish-Like Self Propulsion Using Flexible Piezoelectric Composites

2012 ◽  
Author(s):  
Lejun Cen ◽  
Alper Erturk
Keyword(s):  
Smart Materials ◽  
Electromechanical Coupling ◽  
High Efficiency ◽  
Fiber Composite ◽  
Actuation Voltage ◽  
Robotic Fish ◽  
Circuit Board ◽  
Modeling Framework ◽  
Actuator Dynamics ◽  
Body Theory

The capacity of humankind to mimic fish-like locomotion for engineering applications depends mainly on the availability of suitable actuators. Researchers have recently focused on developing robotic fish using smart materials, particularly Ionic Polymer-Metal Composites (IPMCs), as a compliant, noise-free, and scalable alternative to conventional motor-based propulsion systems. In this paper, we investigate fish-like self propulsion using flexible bimorphs made of Macro-Fiber Composite (MFC) piezoelectric laminates. Similar to IPMCs, MFCs also exhibit high efficiency in size, energy consumption, and noise reduction. In addition, MFCs offer large dynamic forces in bending actuation, strong electromechanical coupling as well as both low-frequency and high-frequency performance capabilities. The experimental component of the presented work focuses on the characterization of an MFC bimorph propulsor for thrust generation in a quiescent fluid as well as the development of a preliminary robotic fish prototype incorporating a microcontroller and a printed-circuit-board (PCB) amplifier to generate high actuation voltage for battery-powered free locomotion. From the theoretical standpoint, a reliable modeling framework that couples the actuator dynamics, hydroelasticity, and fish locomotion theory is essential to both design and control of robotic fish. Therefore, a distributed-parameter electroelastic model with fluid effects and actuator dynamics is coupled with the elongated body theory. Both in-air and underwater experiments are performed to verify the incorporation of hydrodynamic effects in the linear actuation regime. For electroelastically nonlinear actuation levels, experimentally obtained underwater vibration response is coupled with the elongated body theory to predict the thrust output. Experiments are conducted to validate the electrohydroelastic modeling approach employed in this work and to characterize the performance of an MFC bimorph propulsor. Finally, a battery-powered preliminary robotic fish prototype is developed and tested in free locomotion.

Hydroelastic Power and Thrust Generation Using Macro-Fiber Composite Piezoelectrics

2011 ◽  
Author(s):  
Alper Erturk ◽  
Ghislain Delporte
Keyword(s):  
Power Generation ◽  
Piezoelectric Effect ◽  
Fiber Composite ◽  
Harmonic Excitation ◽  
Favorable Effect ◽  
Base Excitation ◽  
Caudal Fin ◽  
Thrust Generation ◽  
Macro Fiber Composite ◽  
Converse Piezoelectric Effect

Flexible piezoelectrics offer several advantages to use in energy harvesting and biomimetic locomotion. These advantages include ease of application, high power density, silent and effective operation over a range of frequencies as well as light weight. Piezoelectric materials exhibit the well-known direct and converse piezoelectric effects. The direct piezoelectric effect has received growing attention for low-power generation to use in wireless electronic applications while the converse piezoelectric effect constitutes an alternative to replace the conventional actuators used in biomimetic locomotion. In this paper, underwater thrust and electricity generation are investigated experimentally by focusing on biomimetic structures with macro-fiber composite piezoelectrics. Fish-like bimorph configurations with and without a passive caudal fin (tail) are fabricated and compared. The favorable effect of having a passive caudal fin on the frequency bandwidth is reported. The presence of a passive caudal fin is observed to bring the second bending mode close to the first one, yielding a wideband behavior in thrust generation. The same smart fish configuration is tested for underwater piezoelectric power generation in response to harmonic excitation from its head. Hydrodynamic loads resulting from base excitation yield considerably larger power output as compared to in-air base excitation at the same acceleration amplitude. This work also discusses the feasibility of thrust generation using the harvested energy toward enabling self-powered swimmer systems.

Nonlinear Actuation Properties of Macro Fiber Composite Actuators

Aerospace ◽  
2003 ◽  
Author(s):  
R. Brett Williams ◽  
Daniel J. Inman ◽  
W. Keats Wilkie
Keyword(s):  
Electric Field ◽  
Mechanical Stress ◽  
Electric Fields ◽  
Experimental Approach ◽  
Large Deformations ◽  
Piezoelectric Effect ◽  
Fiber Composite ◽  
Interdigitated Electrodes ◽  
Piezoelectric Strain ◽  
Macro Fiber Composite

This paper presents an experimental approach to determine the effective piezoelectric strain parameters, d33 and d31, of the Macro Fiber Composite (MFC) actuator. Traditional d31 piezoceramics typically operate at low strain and electric fields levels and are thus adequately modeled using linear piezoelectric theory. However, the MFC has interdigitated electrodes which allow actuation by way of the stronger “d33” piezoelectric effect. The resulting large deformations/stresses often occur in combination with strong applied electric fields and cause the violation of some of the assumptions used in the development of linear piezoelectric theory. Specifically, the piezoelectric “d” parameters are no longer constant, but rather, as the current research indicates, depend on the applied mechanical stress and electric field.

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