Piezoelectric Composite Layer Research Articles

On Flexural Wave Dispersion of a Higher-Order Metamaterial Sandwich Composite Plate Based on a Visco-Pasternak Foundation

This paper elaborates on the wave propagation characteristics of a smart sandwich plate consisting of smart piezo composite layers on a plate’s upper and lower borders via an auxetic core. This study’s equation of motion was derived using a refined version of the Shear-deformation theory at a higher order, or HSDT. Additionally, detecting the properties of the auxetic core and piezoelectric composite layers employs a micromechanical model. The fundamental equations of the smart sandwich plates were formulated utilizing the Hamiltonian principle and Maxwell’s law. Then, the governing equations of a sandwich plate are solved using an exponential form and an analytical method. Furthermore, the phase velocity of the intelligent sandwich plate is provided based on the layer thicknesses of the auxetic core and thicknesses of intelligent piezoelectric composite layers. In addition, each figure calculates and presents the weight of the Winkler–Pasternak coefficient, the viscoelastic substances factor, the source of the outside electricity, and the volume percent of reinforcement in the matrix on the phase velocity.

Effect of orientation of CNTs and piezoelectric fibers on the damping performance of multiscale composite plate

The present work deals with the study of active constrained layer damping treatment of multiscale carbon nanotube-based hybrid carbon fiber-reinforced composite plates. The distinctive feature of novel multiscale hybrid carbon fiber-reinforced composites is that the wavy/straight carbon nanotubes are distributed uniformly in the matrix phase of hybrid carbon fiber-reinforced composites, and the waviness of carbon nanotubes is considered to be coplanar with two mutually orthogonal planes. Firstly, the effective elastic properties of hybrid carbon fiber-reinforced composites are estimated using the Mori-Tanaka method. The outcomes of the Mori-Tanaka method suggest that the transverse effective elastic properties of hybrid carbon fiber-reinforced composites containing wavy carbon nanotubes are better than those of hybrid carbon fiber-reinforced composites with straight carbon nanotubes. Secondly, a finite element model using the layer-wise first-order shear deformation theory is developed to study the damping performance of hybrid carbon fiber-reinforced composite plates integrated with the active constrained layer damping treatment. The constraining layer of active constrained layer damping treatment is a 1–3 piezoelectric composite layer with vertically/obliquely-oriented piezo-fibers. The piezo-fibers make an angle [Formula: see text] with the vertical plane of a layer coplanar with the xz- or yz-plane. The effect of the orientation of piezo-fibers angle on the control authority of active constrained layer damping treatment patches is investigated. Our results reveal that the performance of multiscale hybrid carbon fiber-reinforced composite plates has improved due to the incorporation of wavy carbon nanotubes, and the orientation angle of piezo-fibers has a major impact on the control authority of active constrained layer damping patches. The proposed multiscale composite with the combination of wavy carbon nanotubes and active constrained layer damping patches can be actively used in the aerospace and transport industries to control the mechanical vibrations of structures.

Bioinspired acoustic textiles with nanoscale vibrations for wearable biomonitoring

The smart textile research community is advancing rapidly with the aim of changing the way we wear clothes in the near future. An eardrum-inspired acoustic textile was recently developed that can function as a sensitive audible microphone. The acoustic textile is woven from yarns with a high Young's modulus and thermal drawing composite piezoelectric fibers that can concentrate mechanical stress in the piezoelectric composite layer during the heat drawing process, endowing the fiber with high sensitivity. The acoustic textile can convert even very slight 10⁻⁷ atmospheric pressure waves at audible frequencies into mechanical vibrations with nanometer amplitudes, which further induce the electrical signals through the fibers to detect the direction of sound pulses, broadcast human speech, and capture heartbeats, making it suitable as a wearable platform for long-term biomonitoring.

Smart control of functionally graded sandwich plates by incorporating Murakami zig-zag function

This study is aimed at incorporating the zig-zag effect by Murakami zig-zag function in the development of a finite element model for active constraining layer damping treatment of functionally graded sandwich plates. The present sandwich construction consists of functionally graded facings distanced by a ceramic core. The substrate functionally graded plate is subjected to active constraining layer damping treatment, which in itself is a two-layered material system comprised of a viscoelastic layer and a 1–3 piezoelectric composite layer. The deformation kinematics of the functionally graded sandwich plate active constraining layer damping system is shaped using Murakami zig-zag function, and the finite element model is obtained by the virtual work principle. A standard feedback control system has been implemented, and a MATLAB subroutine has been developed to present the open- and closed-loop responses. Substrate plates with functionally graded configurations 1-1-1, 1-2-1, and 2-1-2 are considered to evaluate the effect of active constraining layer damping on damping the frequency responses of these plates. Investigation on damping performance has been carried out, bearing in mind the change in power-law index with top and bottom ceramic-/metal-rich surfaces. Also, the effect of variation in fiber orientation angle (obliquely reinforced) of the piezoelectric composite material on the active constraining layer damping performance has been examined thoroughly.

Multi-physics modelling of piezoelectric pavement system for energy harvesting under traffic loading

ABSTRACT This study aims to evaluate the field performance of the piezoelectric-based energy harvesting pavement system (PZ-EHPS) under moving traffic loads by multi-physics modelling. Finite element models (FEMs) with multiple physical interfaces were built with the close circuit system. The laboratory scale of FEM was analysed to validate the voltage output as compared to the measurements in laboratory tests. To enhance the computational efficiency of large-scale simulation, a homogenisation approach was developed to convert the piezoelectric composite layer to the homogeneous layer with equivalent mechanical and electric properties. The variations of power output patterns from the PZ-EHPS, with different geometric designs under different traffic loading levels and temperature conditions, were studied. The results show that the width of the PZ-EHPS shall match the wheel path to generate electricity and avoid energy consumption in the area uncovered by traffic loading, during the electricity transmission. The power output of the PZ-EHPS shows an exponential relationship with the increase of load magnitude from vehicles. Future studies are needed to achieve the full utilisation of each function layer for building smart pavement with multiple functions.

Numerical simulation of electromechanical coupling properties of three-dimensional braiding piezoelectric composite actuator

In this paper, an innovative three-dimensional braiding piezoelectric composite actuator (3D-BPCA) is proposed. Based on the 3D braiding technology, the geometric model and representative volume unit (RVU) model of the 3D-BPCA are established. The effective elastic constant, dielectric constant and piezoelectric constant of the braiding piezoelectric composite layer (BPCL) are predicted. The electromechanical properties of the 3D-BPCA under the electromechanical coupling field is theoretically analyzed and numerically simulated, and compared with the piezoelectric ceramics actuator (PZT-5A). Numerical results show that the 3D-BPCA has better actuating properties than the PZT-5A and has a wide application prospects.

Active vibration control of axially functionally graded cantilever beams by finite element method

Axially functionally graded (AFG) beams are a new class of composites where the material properties continuously vary along the longitudinal direction of the beam. In this work a smart finite element model of the AFG beam is formulated based on the Timoshenko beam theory. A patch of distributed actuator is attached at the top surface of the beam and it is made of a constrained viscoelastic layer and a constraining piezo fiber reinforced composite layer. To accurately represent the kinematics of deformation in the viscoelastic and the piezoelectric composite layers, a layerwise effect is incorporated in terms of additional rotational degrees of freedom for each layer. The analyses are done in the frequency domain and the efficacy of the controller is numerically computed for AFG cantilever beams with uniform cross section and varying elastic coefficient and density along the longitudinal direction. Results are compared for beams with different material distribution and it is found that the controller performance is better when the fixed side of the AFG beam has higher elastic modulus and density.

Power amplification via compliant layer interdigitation and dielectrophoretic structuring of PZT particle composites

The evolution of portable electronics has led to recent popularity of piezoelectric materials for energy harvesting, especially for devices deployed remotely or in vivo. The efficiency of piezoelectric generators harvesting energy from the human body is lacking due to off-resonance loading. Piezoelectric ceramics are expensive to manufacture and are dense, brittle, and difficult to use in high strain environments. Piezoelectric composites composed of ferroelectric particles distributed in a polymer matrix are desirable due to low cost and tunable properties. In this study, Compliant Layer Adaptive Composite Stacks (CLACS) made with thin piezoelectric composite layers structured by dielectrophoresis (DEP) were investigated to increase the energy harvesting efficiency at low frequency loading. To predict power generation capabilities, a theoretical model was developed by using established particle composite models in conjunction with a shear lag structural mechanics model for CLACS. Granular composite discs of lead zirconate titanate particles in an epoxy matrix were manufactured at a 50% volume fraction and structured by DEP, if applicable. CLACS were manufactured using composite discs and two compliant layer thicknesses. The stacks were electromechanically tested by varying load, frequency, and resistance. Experimental results showed a significant increase in power amplification with DEP structured discs and compliant layer interdigitation. In addition, the theoretical model accurately predicts power production for both 0–3 and 1–3 CLACS at low frequencies. DEP structured particle composite CLACS can provide a method of energy harvesting for devices in remote locations, especially in low frequency high strain environments.

Active Control of Geometrically Nonlinear Vibrations of Laminated Composite Beams Using Piezoelectric Composites by Element-Free Galerkin Method

In this article, active control of geometrically nonlinear transient vibrations in laminated composite beams has been demonstrated using an advanced piezoelectric composite (PZC) layer as the active layer with a proper control strategy. A nonlinear mesh free (MF) model is derived for analyzing the dynamic characteristics of the laminated composite beams integrated with the PZC patch based on the element-free Galerkin (EFG) method within the framework of a layer wise beam theory considering transverse shear deformations. The Von Kármán type nonlinear strain–displacement relationships are considered for formulating the coupled electromechanical nonlinear MF model. Both in-plane and transverse actuation by the PZC layer have been taken into consideration for deriving the model. Various geometrical shapes of the PZC layers have been considered for the analysis to understand the geometrical shape dependency of the PZC layer in attenuating vibration in the structure. The numerical results indicate that the PZC layer significantly improves the dynamic characteristics of the laminated beams by suppressing the geometrically nonlinear transient vibrations induced in them. It has been also noticed that the irregular shaped PZC patches like triangular PZC patches perform better as compared to the regular rectangular PZC patches in alleviating vibration the structure.

Piezoelectric Micro- and Nanostructured Fibers Fabricated from Thermoplastic Nanocomposites Using a Fiber Drawing Technique: Comparative Study and Potential Applications

We report an all-polymer flexible piezoelectric fiber that uses both judiciously chosen geometry and advanced materials in order to enhance fiber piezoelectric response. The microstructured/nanostructured fiber features a soft hollow polycarbonate core surrounded by a spiral multilayer cladding consisting of alternating layers of piezoelectric nanocomposites (polyvinylidene enhanced with BaTiO3, PZT, or CNT) and conductive polymer (carbon-filled polyethylene). The conductive polymer layers serve as two electrodes, and they also form two spatially offset electric connectors on the fiber surface designed for the ease of connectorization. Kilometer-long piezoelectric fibers of sub-millimeter diameters are thermally drawn from a macroscopic preform. The fibers exhibit high output voltage of up to 6 V under moderate bending, and they show excellent mechanical and electrical durability in a cyclic bend−release test. The micron/nanosize multilayer structure enhances in-fiber poling efficiency due to the small distance between the conducting electrodes sandwiching the piezoelectric composite layers. Additionally, the spiral structure greatly increases the active area of the piezoelectric composite, thus promoting higher voltage generation and resulting in 10−100 higher power generation efficiency over the existing piezoelectric cables. Finally, we weave the fabricated piezoelectric fibers into technical textiles and demonstrate their potential applications in power generation when used as a sound detector, smart car seat upholstery, or wearable materials.

Piezoelectric Micro- and Nanostructured Fibers Fabricated from Thermoplastic Nanocomposites Using a Fiber Drawing Technique: Comparative Study and Potential Applications

We report an all-polymer flexible piezoelectric fiber that uses both judiciously chosen geometry and advanced materials in order to enhance piezoelectric response. The microstructured/nanostructured fiber features a soft hollow polycarbonate core surrounded with a spiral multilayer cladding consisting of alternating layers of piezoelectric nanocomposites and conductive polymer. Kilometer-long piezoelectric fibers of submilimeter diameters are thermally drawn from macroscopic preforms. The fibers exhibit high output voltage of up to 6V under moderate bending, and they show excellent durability in a cyclic bend-release test. The micron/nano-size multilayer structure enhances in-fiber poling efficiency thanks to the small distance between the conducting electrodes sandwiching the piezoelectric composite layers. Additionally, spiral structure greatly increases the active area of piezoelectric composites, thus promoting higher voltage generation and resulting in 10-100 higher power generation efficiency over the existing piezoelectric cables. Finally, we weave the piezoelectric fibers into technical textiles and demonstrate their potential applications in power generation.

Piezoelectric Micro- and Nanostructured Fibers Fabricated from Thermoplastic Nanocomposites Using a Fiber Drawing Technique: Comparative Study and Potential Applications

We report an all-polymer flexible piezoelectric fiber that uses both judiciously chosen geometry and advanced materials in order to enhance fiber piezoelectric response. The microstructured/nanostructured fiber features a soft hollow polycarbonate core surrounded by a spiral multilayer cladding consisting of alternating layers of piezoelectric nanocomposites (polyvinylidene enhanced with BaTiO3, PZT, or CNT) and conductive polymer (carbon-filled polyethylene). The conductive polymer layers serve as two electrodes, and they also form two spatially offset electric connectors on the fiber surface designed for the ease of connectorization. Kilometer-long piezoelectric fibers of sub-millimeter diameters are thermally drawn from a macroscopic preform. The fibers exhibit high output voltage of up to 6 V under moderate bending, and they show excellent mechanical and electrical durability in a cyclic bend-release test. The micron/nanosize multilayer structure enhances in-fiber poling efficiency due to the small distance between the conducting electrodes sandwiching the piezoelectric composite layers. Additionally, the spiral structure greatly increases the active area of the piezoelectric composite, thus promoting higher voltage generation and resulting in 10-100 higher power generation efficiency over the existing piezoelectric cables. Finally, we weave the fabricated piezoelectric fibers into technical textiles and demonstrate their potential applications in power generation when used as a sound detector, smart car seat upholstery, or wearable materials.

Dynamic analysis of functionally graded circular cylindrical panel with piezoelectric fiber composite actuator and sensor

A three-dimensional piezoelasticity analysis is presented for a functionally graded circular cylindrical panel with piezoelectric fiber composite layers as sensor and actuator under dynamic load and electrical excitation. It is assumed that the material properties of functionally graded material obey the power law. Moreover, the effective properties of the piezoelectric composite layers are derived from the properties of their constituents using iso-field assumption. Three-dimensional finite element analysis is applied to solve the coupled partial differential equations (PDEs), including Maxwell’s equation for electric displacement and three equations of motion. Discretized governing equations are solved over time domain using Houbolt time integration scheme. The stress and potential electricity results are compared for various supports, electrical excitation voltages, and volume fractions. Moreover, the results are provided versus time domain and a comparison has been made between sensor voltage and the corresponding stress component.

Bendable Electro-Acoustic Transducer Fabricated Utilizing Frequency Dispersion of Elastic Modulus

To realize the speaker diaphragm that can be united with a flexible display without deteriorating lightweight properties and flexibility, a novel bendable electro-acoustic transducer (BEAT) based on 0–3-type piezoelectric composites has been developed. To overcome the trade-off between flexibility and the transmission efficiency of vibration energy, a viscoelastic polymer that has local maximum points in the loss factor as well as large frequency dispersion in the storage modulus near room temperature was employed as the matrix of the piezoelectric composite layer. Against the comparatively slow (10 Hz or less) deformation from the outside, the viscoelastic matrix is viscous enough to prevent cracking and delamination. On the other hand, in the audible range (20 Hz to 20 kHz), the matrix is elastic enough to transmit piezoelectric vibration energy, maintaining a moderately large loss factor as well as a high sound velocity. For the first time, we successfully demonstrated a rollable speaker that can continue to generate a high-quality sound while being rolled and unrolled repeatedly onto a cylinder with a curvature radius of 4 mm.

Smart damping of laminated fuzzy fiber reinforced composite shells using 1–3 piezoelectric composites

This paper deals with the investigation of active constrained layer damping (ACLD) of smart laminated continuous fuzzy fiber reinforced composite (FFRC) shells. The distinct constructional feature of a novel FFRC is that the uniformly spaced short carbon nanotubes (CNTs) are radially grown on the circumferential surfaces of the continuous carbon fiber reinforcements. The constraining layer of the ACLD treatment is considered to be made of vertically/obliquely reinforced 1–3 piezoelectric composite materials. A finite element (FE) model is developed for the laminated FFRC shells integrated with the two patches of the ACLD treatment to investigate the damping characteristics of the laminated FFRC shells. The effect of variation of the orientation angle of the piezoelectric fibers on the damping characteristics of the laminated FFRC shells has been studied when the piezoelectric fibers are coplanar with either of the two mutually orthogonal vertical planes of the piezoelectric composite layer. It is revealed that radial growth of CNTs on the circumferential surfaces of the carbon fibers enhances the attenuation of the amplitude of vibrations and the natural frequencies of the laminated FFRC shells over those of laminated base composite shells without CNTs.

Active constrained layer damping of geometrically nonlinear vibration of rotating composite beams using 1-3 piezoelectric composite

In this paper, an analysis for active constrained layer damping (ACLD) of rotating composite beams undergoing geometrically non linear vibrations has been carried out. Commercially available vertically/obliquely reinforced 1-3 piezoelectric composite (PZC) material has been used as the material of the constraining layer of the ACLD treatment. A finite element (FE) model has been derived to carry out the analysis. The substrate beam is considered thin and hence, first order shear deformation theory (FSDT) and von-Karman type nonlinear strain–displacement relations are used to derive the coupled electromechanical nonlinear FE model. The rotary effect has been suitably modelled by incorporating extensional strain energy due to centrifugal force. The Golla–Hughes–McTavish method has been employed to model the constrained viscoelastic layer of the ACLD treatment in the time domain. The numerical responses revealed that the ACLD treatment with 1-3 PZC constraining layer efficiently performs the task of active damping of geometrically nonlinear vibrations of the rotating composite beams. The effects of the fibre orientation angles of the angle-ply substrate beams and the 1-3 PZC constraining layer on the ACLD of the geometrically nonlinear vibrations have been investigated. Also, the effect of the thickness variations of the 1-3 PZC layer and the viscoelastic constrained layer on the damping characteristics of the overall rotating composite beams has been studied.

Static and dynamic responses analysis for 1–3 piezocomposite laminates with Interdigitated Electrodes

The static and dynamic responses analysis for the 1-3 piezocomposite laminates equipped with Interdigitated Electrodes (IDE) is performed with analytical method. In the static analysis, the solution of the derived governing dif ferential equations is obtained through the power series expansion and Fourier expansion methods. In the dynamic analysis, the governing equations for the transverse vibration are established bas ed on the thin plate theory, and the solutions are obtained through the separation of variables and Fourier expansion methods. The illustrative analysis is carried out to investigate the static and dynamic characteristics of the laminated plates. The numerical results show that, the magnitude of shear curvature gradually increases with the increment of the stiffness anisotropy and the free-strain anisotropy of the piezocomposite and the vibration suppression can be also achieved by adopting a time-dependent control voltage to the IDE of the piezocomposite. Investigators have developed several numerical and analytical models for the static and dynamic control of laminated plates with piezoelectric ceramic sensors and actuators. A pioneering work is due to Alik and Hughes (4), which analyzed the interactions between electricity and elasticity. Ray et al. (5) studied the exact static analysis of piezoelectric plates under cyl indrical bending. Comparing with the analysis of laminate plates with piezoelectric layers, the work repo rted in the area of laminated plate with 1-3 piezocomposite layers is still quite limited, especially f or the analytical analysis of the static and dynamic control of laminates with 1-3 piezoelectric composite layer equipped with the IDE. In this paper, the static

Stress analyses of a smart composite pipe joint integrated with piezoelectric composite layers under torsion loading

In order to improve the joint failure strength, an adhesively bonded smart composite pipe joint system has been developed by integrating electromechanical coupling piezoelectric layers with the connection coupler. It has been validated that the integrated piezoelectric ceramic layers can smartly reduce stress concentration in the adhesive layer bond-line under bending or axial tension loads. In this study, piezoelectric particle/fiber reinforced polymer composite was utilized to construct adhesively bonded smart composite pipe joint systems, in order to overcome the brittle characteristic of the piezoelectric ceramic layers and to facilitate joint construction. Since torsion is one of the dominating loading conditions in practice, the behavior of the newly developed smart pipe joint system subjected to torsion loading was investigated in-detail to evaluate the effect of the integrated piezoelectric reinforced polymer composite layer on the joint performance. Firstly, based on the first-order shear deformation theory, the fundamental equations with relevant boundary and continuity conditions were developed to theoretically model the smart pipe joint system subjected to torsion loading. Further, the analytical solutions for the mid-plane displacements and the shear and peel stresses in the adhesive layer were obtained by using the Levy solution and the state-space method. Finally, some numerical examples were presented to evaluate the detailed effect of the stacking sequence and thickness of the integrated composite piezoelectric layers in the connection coupler on reducing the stress concentration in the adhesive layer; the effect of the applied electric fields on shear and peel stresses in the adhesive layer was also illustrated.

Design and analysis of a smart adhesive single-strap joint system integrated with the piezoelectrics reinforced composite layers

In order to reduce the peel/shear stresses concentration influence in the adhesive layer line, a smart adhesively bonded single-strap joint system was developed to decrease the maximum peel and shear stresses in the adhesive layer by the integrated piezoelectric reinforced composite layers as sensors/actuators. In present smart joint system, owing to the integrated piezoelectric reinforced composite layers, the mechanical loading induced deformation of adhesive joint system can be detected and monitored by the integrated sensing piezoelectric composite layers and then fed back to the integrated actuating piezoelectric composite layers to adaptively create the additional forces and moments to reduce the maximum peel and shear stresses in the adhesive layer. In order to theoretically verify the efficiency of present developed smart joint system, an electro-mechanical theoretical model was employed to investigate the smart adhesive joint system based on the first-order shear deformation theory. Further, the analytical solutions for the peel and shear stresses distribution were carried out by the state-space method. Finally, some numerical results were calculated to validate the integrity of the developed smart adhesive single-strap joint system.

2D-Elasticity Analysis of FGM Piezo-Laminates Under Cylindrical Bending

Elastic behavior of piezo-laminates under cylindrical bending is studied using 2D-elasticity model and classical lamination theory (CLT). The stresses and out-of-plane displacements are obtained for standard piezoelectric bimorph and newly proposed piezoelectric laminate with functionally graded microstructure (FGM) plates under cylindrical bending generated by electric field throughout the thickness of the laminate. The FGM piezoelectric laminates are composite materials whose electroelastic properties are varied through their thickness. The properties can vary in a continuous or a stepwise manner. The FGM laminate investigated in this paper is of a stepwise FGM where different piezoelectric composite layers are stacked to form FGM laminate. The feasibility of FGM laminate is studied. The limitations of CLT are investigated against the 2D-elasticity model. CLT solutions are found to coincide well with the elasticity solutions for high aspect ratios while the CLT solutions gave poor results compared to the 2D-elasticity solutions for low aspect ratios. The analytical models, CLT and 2D-elasticity, are investigated against the Finite Element Methods (FEM). Standard bimorph of piezoelectric actuator was fabricated and the displacement measurements resulted in a good agreement to the analytical and FEM results.