Composite structures which show magneto-electric (ME) coupling behavior have a wide range of engineering applications. In this work, a composite structure comprising of a ferroelectric and a magnetostrictive material is taken for investigation. First, the nonlinear responses of the ferroelectric material and the magnetostrictive material are studied separately by experiments. In order to predict the nonlinear response, a thermodynamically consistent macroscopic model is proposed for the ferroic materials. Model parameters are then estimated from the experimental data, and the simulated results based on the proposed model are presented. Results from the theoretical model are in agreement with the experimental data. Subsequently, a homogenization procedure is introduced to find out the nonlinear response of a layered ME composite structure, and the obtained results are discussed. © 2017, Springer-Verlag Wien.

Arunachalakasi Arockiarajan

Department of Applied Mechanics

Sk M. Subhani

Composite structures

Ferroelectric materials

Ferroelectricity

Structure (composition)

ELECTROMECHANICAL RESPONSE

Engineering applications

Experimental approaches

HOMOGENIZATION PROCEDURE

MAGNETOELECTRIC COMPOSITES

MAGNETOSTRICTIVE MATERIAL

Non-linear response

Theoretical modeling

MAGNETOSTRICTIVE DEVICES

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

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IIT Madras

Acta Mechanica

Magnetoelectric (ME) composites exhibit the magnetoelectric effect, which is a coupling phenomenon resulting from the interaction between the magnetostrictive and piezoelectric phases. This makes ME composites useful as multifunctional devices in a variety of applications. In this work, a press-fit epoxy-free nested ring structured ME composite has been fabricated, in which nickel and FeNi form the magnetostrictive phase and PZT-5A constitutes the piezoelectric phase. To conduct a comparative study, epoxy bonded conventional bilayered and trilayered ME composites of the same material constituents and similar volume fractions have also been made. Magnetostriction measurements are done on individual magnetostrictive materials at varying temperatures in longitudinal and transverse directions. Measurement of the ME coefficient is done on all the prepared composites and their relative response at elevated temperatures is presented. Self-biased behavior of the ME composites resulting out of the applied prestress is also captured. A 2D hysteretic model including the temperature and prestress effects that can capture the behavior of epoxy-free ring composites has also been formulated. The results from the model are in agreement with the experimental results at all the temperatures. The obtained experimental results highlight the suitability of epoxy-free ring composites to be used in high temperature microdevices. © 2019 Author(s).

Fulltext

Journal of Applied Physics

Temperature dependent magnetoelectric (ME) response in press-fit FeNi/PZT/Ni self-biased ring composite

An experimental investigation has been carried out to capture the magneto-mechanical behavior and material parameters of magnetostrictive material. Further, the experimental study is extended to capture the magnetoelectric (ME) coupling response of trilayered composites by applying both alternating and static magnetic fields. From the experiments, it is observed that the magnetostrictive material has a nonlinear hysteretic behavior. Hence, a three dimensional (3-D) nonlinear constitutive model has been proposed based on a thermodynamic framework and multisurface plasticity. In ME composites, it is also observed that a large ME coupling response can be obtained while operating near resonance frequencies. To capture the resonant ME effects, a theoretical formulation has been proposed based on axial vibrations theory and the proposed constitutive model has been incorporated in the formulation. The simulated resonant ME coupling response based on the proposed formulation is compared with the experimental data and found to be in agreement with each other. Further, a parametric study has been performed to address the variation of the resonant ME response as a function of various parameters such as axial compliance ratio, volume fraction of constituents, temperature, direction of magnetic loading and aspect ratio. This study reveals that the coupling response can be optimized by choosing the suitable parameters based on design requirement. © 2019 Elsevier Masson SAS

European Journal of Mechanics, A/Solids

Study on axial resonance magneto-electric (ME) effects of layered magneto-electric composites

Piezocomposites find extensive use in sensors and actuators, naval applications, etc. owing to their characteristic coupling between electro-mechanical domains. These materials being relatively soft and ductile show a viscoelastic response to applied thermo-mechano-electrical loads. This causes a drift in the system response and creep is observed, which affects system efficiency. During prolonged service periods, self-heating occurs. Often, piezocomposites are subjected to mechanical pre-stresses prior to electrical input. To understand the response of 1–3 piezocomposites under these intricate loading conditions, experiments are performed to study the electro-mechanical response of 1–3 piezocomposites under thermo-mechano-electrical creep loads. Mechanical depolarisation is observed during the creep process. Creep strain is observed to increase with matrix volume fraction, mechanical pre-stress, electric field and temperature. A decrement in creep polarisation is seen with the increase in matrix volume fraction, mechanical pre-stress and temperature. The system performance is observed to be strongly dependent on the fibre volume fraction. A hybrid model is proposed within a thermodynamic framework to predict the creep response of 1–3 piezocomposites under thermo-mechano-electrical loads. The model is simultaneously representative of the macroscopic phenomenological details and mesoscopic electro-mechanical insights. While the free energy potential and domain switching concepts are characteristic of macroscopic modelling, the representative volume element (RVE) and its description with regard to domain wall resistance can be related to the mesoscopic length scales. The model predictions are found to be in agreement with the experimental observations. © 2018, © 2018 Informa UK Limited, trading as Taylor & Francis Group.

Philosophical Magazine

A hybrid phenomenological model for thermo-mechano-electrical creep of 1–3 piezocomposites

1-3 piezocomposites are often subjected to mechanical pre-stress under elevated temperatures in naval and offshore applications, actuators, and so on, where the presence of the ductile epoxy matrix causes considerable creep in the system. This deteriorates the system efficiency and its overall performance. To address this issue, experiments are performed to capture the electromechanical response for thermo-mechanical creep of 1-3 piezocomposites for different fiber volume fractions under various thermal loads, wherein mechanical depolarization is observed. The piezo-coupling coefficient is observed to degrade. Higher thermal loads resulted in an increase in creep strain coupled with a decrease in creep polarization. A Kelvin–Voigt fractal derivative viscoelastic model is used to capture the creep strain. The creep strain is decomposed into ferroelastic and anelastic parts. The evolution of creep polarization is obtained using the ferroelastic component of the creep strain. The model predictions are found to be in agreement with the experimental observations. © The Author(s) 2019.

Journal of Intelligent Material Systems and Structures

Experimental characterization and viscoelastic modeling for thermo-mechanical creep of 1-3 piezocomposites

In this study, a thermodynamically consistent constitutive relation is developed for ferroelectric materials. The present model is developed in such a way that an intermediate variable is introduced as a stored variable which accounts for calculating the internal variable. Due to this approach, simulations can be performed without an iterative procedure. Thus, this model improves the computational efficiency. The algorithmic procedure can also handle the evolution of ferroelastic strain as well as the evolution of polarisation simultaneously, without getting into convergence issues. In this work, simulations have been performed to capture various behaviours such as ferroelectric hysteresis with prestress, mechanical depolarisation, ferroelastic hysteresis, and creep behaviour. The simulated results have been compared with the experimental results, and it is observed that the model is good enough to capture various nonlinear hysteresis behaviours. © 2018, Springer-Verlag GmbH Austria, part of Springer Nature.

A phenomenological model for nonlinear hysteresis and creep behaviour of ferroelectric materials

Further development and design of piezoelectric composites enhances the improved use of piezoelectric materials and devices by overcoming their brittleness. In order to engineer this class of materials and to predictably simulate its behaviour, a computationally efficient constitutive model is established in this paper. This contribution deals with the development of a model for piezoelectric composites to capture their effective behaviour. We first discuss a three-dimensional fully coupled electromechanical rate-dependent model for the response of ferroelectric ceramics. Secondly, a simple homogenisation approach is applied to capture the behaviour of composites for various volume fractions of PZT fibres under different loading frequencies. Following this, a finite element formulation is applied in order to study the behaviour of composites. Finally, these two approaches are compared with experimental results. © 2015 Elsevier Ltd.

Mechanics of Materials

Experimental investigation, modelling and simulation of rate-dependent response of 1-3 ferroelectric composites

Depending on the maximum amplitude of externally applied cyclic electric fields, ferroelectric ceramics show minor or major hysteresis. The materials also show asymmetric butterfly hysteresis in a prepoled material. Aiming at capturing these behaviour in a phenomenological constitutive model, a multi-surface modelling approach for ferroelectrics is introduced. In this paper, with the note on the motivation for a multi-surface model related to the results of new experimental investigations and also to experimental data reported in the literature, the constitutive relation for a rate dependent multi-surface ferroelectric model is developed. Following this, a brief graphical illustration shows how this model captures the objective phenomena. Consequently, the numerical implementation of the model to capture experimental results is demonstrated. Finally, the performance of this model to represent behaviour of decaying polarisation offset of electrically fatigued specimen is shown. © 2016 Informa UK Limited, trading as Taylor & Francis Group.

A multi-surface model for ferroelectric ceramics - Application to cyclic electric loading with changing maximum amplitude

An analytical model based on equivalent layered approach based on iso-field assumptions is proposed to evaluate the effective properties of layered multi-ferroic composites where three phases (piezoelectric, piezomagnetic and epoxy) are considered for homogenization. Also, a finite element (FE) analysis with periodic boundary conditions is carried out in the present work to determine the effective properties of multiferroics wherein interphase and geometric (shape and position) properties are considered. The simulated results based on the proposed analytical and numerical models are compared with exact matrix method available in the literature. Experiments are performed on multiferroic composites under magnetic loading to measure magneto-electric (ME) coupling constant and the results are compared with the simulated results. A parametric study is conducted to investigate the variations of the overall material behavior of layered composite with respect to piezoelectric and piezomagnetic poling/orientation directions. The outcome of the present study demonstrates the influence of poling and orientation of individual constituents on effective properties of multiferroic composites. © 2015 Elsevier B.V.

Sensors and Actuators, A: Physical

Analytical, numerical and experimental studies on effective properties of layered (2-2) multiferroic composites

Domain switching in piezoelectric materials is caused by external loads such as electric field and stress that leads to non-linear behaviour. A study is carried out to compare the non-linear behaviour of 1-3 piezocomposites with different volume fractions and bulk piezoceramics. Experiments are conducted to measure the electrical displacement and strain on piezocomposites and bulk ceramics under high cyclic electrical loading and constant compressive prestress. A thermodynamically consistent uni-axial framework is developed to predict the nonlinear behaviour by combining the phenomenological and micromechanical techniques. Volume fractions of three distinct uni-axial variants (instead of six variants) are used as internal variables to describe the microscopic state of the material. In this model, the grain boundary effects are taken into account by introducing the back fields (electric field and stress) as non-linear kinematic hardening functions. An analytical model based on equivalent layered approach is used to calculate effective properties such as elastic, piezoelectric, and dielectric constants for different volume fractions of piezocomposites. The predicted effective properties are incorporated in the proposed uni-axial model and the dielectric hysteresis (electrical displacement versus electric field) as well as butterfly curves (strain versus electric field) are simulated. Comparison between the experiments and simulations show that this model can reproduce the characteristics of non-linear response. It is observed that the variation in fiber volume fraction and compressive stress has a significant influence on the response of the 1-3 piezocomposites. © 2013 Elsevier Ltd. All rights reserved.

Journal	Data powered by TypesetActa Mechanica
Publisher	Data powered by TypesetSpringer-Verlag Wien
ISSN	00015970
Open Access	No