Micromechanics-based predictions of effective properties of a 1-3 piezocomposite reinforced with hollow piezoelectric fibers (original) (raw)
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Transstellar Journals, 2020
In this paper, modified strength of materials (MSM) and strain energy-based approach have been used to determine effective electro-mechanical properties of piezoelectric fiber reinforced composites (PFRC). Based upon these methods, micromechanics model has been formulated using a rectangular representative volume element (RVE) which contains both fiber as well as matrix phases. Result obtained has been compared with strength of materials (SM) approach to the similar problems available in literatures. Results suggest that there is wide variation in estimation of properties obtained through strength of materials method to the methods adopted in this work. Strength of materials (SM) method in most of cases overestimates or underestimates the actual result. Though each of such approaches has its own limitations, the adopted method in this paper refines result obtained through strength of materials (SM), as it takes into account of the several conditions, which has not been dealt while analysing with strength of materials method. Both modified strength of materials and energy approach reduces aberration generated in result, due to generation of unequal strain in matrix and fiber phases as well as Poisson's ratio mismatch between fiber and matrix phases.
Advance In Micromechanics Analysis of Piezoelectric Composites
This paper presents an overview of micromechanics analysis of piezoelectric composites. Developments in micromechanics algorithms, finite element, and boundary element formulation for predicting effective material properties of piezoelectric composites are described. Finally, a brief summary of the approaches discussed is provided and future trends in this field are identified.
2012
A previous study on the characterization of effective material properties of a d 15 thicknessshear piezoelectric Macro-Fibre Composite (MFC) made of seven layers (Kapton, Acrylic, Electrode, Piezoceramic Fibre and Epoxy Composite, Electrode, Acrylic, Kapton) using a finite element homogenization method has shown that the packaging reduces significantly the shear stiffness of the piezoceramic material and, thus, leads to significantly smaller effective electromechanical coupling coefficient k 15 and piezoelectric stress constant e 15 when compared to the piezoceramic fibre properties. Therefore, the main objective of this work is to perform a parametric analysis in which the effect of the variations of fibre volume fraction, Epoxy elastic modulus, electrode thickness and active layer thickness on the MFC effective material properties is evaluated. Results indicate that an effective d 15 MFC should use relatively thick fibres having relatively high shear modulus and relatively stiff epoxy filler. On the other hand, the electrode thickness does not affect significantly the MFC performance. This work presented a parametric analysis of the effective material properties of a d 15 thickness-shear piezoelectric Macro-J. of the Braz. Soc. of Mech. Sci. & Eng.
Smart Materials and Structures, 2006
Numerical unit cell models of 1-3 periodic composites made of piezoceramic unidirectional cylindrical fibers embedded in a soft non-piezoelectric matrix are developed. The unit cell is used for prediction of the effective coefficients of the periodic transversely isotropic piezoelectric cylindrical fiber composite. Special emphasis is placed on a formulation of the boundary conditions that allows the simulation of all modes of the overall deformation arising from any arbitrary combination of mechanical and electrical loading. The numerical approach is based on the finite element method and it allows extension to composites with arbitrary geometrical inclusion configurations, providing a powerful tool for fast calculation of their effective properties. For verification, the effective coefficients are evaluated for square and hexagonal arrangements of unidirectional piezoelectric cylindrical fiber composites. The results obtained from the numerical technique are compared with those obtained by means of the analytical asymptotic homogenization method for different volume fractions. Furthermore, the results are compared with other analytical and numerical methods reported in the literature.
Materials which exhibit piezoelectric behavior generate an electrical field in response to a mechanical deformation or alternatively undergo a mechanical deformation in response to an applied electrical field. This work presents the development of unit cell numerical models of 1-3 periodic composites, with piezoelectric fibers made of PZT embedded in a non-piezoelectric matrix. The common approach for estimating the macro-mechanical properties of 3D piezoelectric fiber composites is carried out by the unit cell approach, also called a representative volume element (RVE), which captures the major features of the underlying micro-structure. The main idea of this method consisting on evaluating a globally homogeneous medium equivalent to the original composite, where the strain energies stored in the two systems are approximately the same, with special emphasis placed on the formulation of suitable boundary conditions. The boundary conditions allow the simulation of all modes of the ov...
International Journal of Solids and Structures, 2005
The present work deals with the modeling of 1-3 periodic composites made of piezoceramic (PZT) fibers embedded in a soft non-piezoelectric matrix (polymer). We especially focus on predicting the effective coefficients of periodic transversely isotropic piezoelectric fiber composites using representative volume element method (unit cell method). In this paper the focus is on square arrangements of cylindrical fibers in the composite. Two ways for calculating the effective coefficients are presented, an analytical and a numerical approach. The analytical solution is based on the asymptotic homogenization method (AHM) and for the numerical approach the finite element method (FEM) is used. Special attention is given on definition of appropriate boundary conditions for the unit cell to ensure periodicity. With the two introduced methods the effective coefficients were calculated for different fiber volume fractions. Finally the results are compared and discussed.
2009 Brazilian Symposium on …, 2009
Piezoelectric fiber composites have several potential applications in aerospace industry due the high level design requirements that can be provided for this kind of material in applications such as structure health monitoring, precision positioning and vibration control or suppression. Difficulties in fiber manufacturing techniques and behavior prediction are the main obstacles to the practical implementation of this technology. In this work one procedure for determining effective properties of one ply made of unidirectional fibers from individual properties of the constituent materials and composite characteristics is presented and discussed. The procedure is based in the modeling of a Representative Volume Element (RVE) or a unit cell by finite element method. The RVE is analyzed under several loading and boundary conditions in order to evaluate of the effective material coefficients (elastic, dielectric end piezoelectric). The results are discussed and compared with analytical and numerical results presented by other researchers.
Great progress has been made over the past decade in the field of smart materials and structures, which are capable of self monitoring and/or self-adapting, by using bonded or embedded sensors and actuators with the control systems. Piezoelectric Fiber Composites (PFC) is one such smart material. They were previously introduced as an alternative to monolithic piezoelectric ceramics. The present paper serves to provide information on the production and design of piezoelectric composite materials. The developed fabrication process lead to unidirectional segmented PFC. Each piezocomposite segment with metallic ends is separated with a polymeric joint. The structure studied here is a beam equipped with two inserts contain N segments on its upper and lower faces. A FEM model is developed using ANSYS® program to predict the effective electromechanical coupling coefficient of the studied beam. This model is used to examine the trends of piezocomposite properties versus the three main param...
Electromechanical properties of continuous fibre-reinforced piezoelectric composites
Mechanics of Composite Materials, 1997
A composite material with unidirectional cylindrical ®bers periodically distributed is considered here, where each periodic cell is a binary homogeneous piezoelectric medium with square symmetry in welded contact at the interface. This paper makes use of some results obtained for a similar elastic composite in Rodr õguez-Ramos et al. [Mech. Mater. 33 (2001) 223±235]. Relatively simple closed-form expressions for the overall properties are obtained by the asymptotic homogenization method. The local problems that arise are solved by means of potentials methods of a complex variable and Weierstrass elliptic and related functions. Benveniste and Dvorak universal type of relations for some of the overall properties are derived in a simple new way without solving any local problem. The number of local problems to get all coecients is 3. The numerical computation of the eective properties is simple. Averaged properties of these piezocomposites relevant to hydrostatic and medical imaging transducer applications are computed and compared with existing experimental results. The comparison shows quite a good agreement with experimental data. Ó
Numerical and analytical analyses for active fiber composite piezoelectric composite materials
Journal of Intelligent Material Systems and Structures, 2014
This work consists of the calculation of the effective properties for Active Fiber Composites (AFCs) made of either circular or square cross-section fibers not only by using Finite Element Analysis (FEA) and Representative Volume Elements (RVE), but also based on Asymptotic Homogenization Method (AHM). Thus, there is an investigation about different approaches, which have specific mathematical formulations and unique characteristics. The comparison between numerical and analytical approaches shows that the numerical results are in good agreement with investigations performed by both analytical and semi-analytical methods (SAM), mainly the predictions for loading applied in fiber direction. For AFC made of circular cross-section fibers, the maximum difference between AHM and FEA is from 1.29% to 5.49% for mechanical and piezoelectric effective properties, respectively, considering RVE in square arrangement. However, for AFC made of square cross-section fibers, the maximum difference between SAM and FEA is from 2.15% to 17.09% for mechanical and piezoelectric effective properties, respectively, considering RVE in square arrangement.