Effective properties of a transversely isotropic piezoelectric composite with cylindrical inclusions

This paper presents a simulation-based study to investigate the damping properties of a novel piezocomposite, consisting of piezoelectric fiber and epoxy reinforced with randomly orientated double walled carbon nanotubes (DWCNT), termed as piezoelectric fiber nano reinforced composite (PFNRC). Authors have observed that the past research dealt with the effect of aligned single walled carbon nanotubes (CNT) on active damping of piezoelectric composite in extension mode (e13 and e33). It is known from the past research that DWCNT inclusions improve the passive damping of a composite. Therefore, the authors use DWCNT inclusions to study the active-passive damping of the piezoelectric composite, in this article. The random orientation of the DWCNT is considered to replicate the physical composite as it known that aligning CNTs in a single direction is not feasible due to fabrication constraints. A multistep homogenization method involving Method of Cells (MOC) is employed to obtain effective properties of PFNRC. A modified 3D-MOC is used to obtain the effective properties of epoxy matrix with DWCNT inclusions (DWCNT-epoxy), considering the effect of nano particle agglomeration. A 2D-MOC is then implemented with long fiber PZT as the active material and DWCNT-epoxy as the matrix. This procedure is followed for computing the effective material properties of extension (e33) as well as shear (e15) mode of PFNRC, when DWCNT inclusions are added into the epoxy matrix at different weight percentages. The constitutive equations are derived with the help of Maple and simulated in MATLAB. These results are used to compare the active-passive damping performance of the composites using a single degree of freedom damping model, employing Newmark’s numerical integration method. The active damping performance of the composites is evaluated by varying the displacement and velocity gains in a negative feedback system. The main focus of the study is to find the most efficient operating mode of the proposed composite for damping of structural vibrations.

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Exact results in the micromechanics of fibrous piezoelectric composites exhibiting pyroelectricity

Proceedings of the Royal Society of London. Series A: Mathematical and Physical Sciences ◽

10.1098/rspa.1993.0048 ◽

1993 ◽

Vol 441 (1911) ◽

pp. 59-81 ◽

Cited By ~ 47

Keyword(s):

Transversely Isotropic ◽

Dielectric Constants ◽

Local Fields ◽

Piezoelectric Composite ◽

Uniform Temperature ◽

Piezoelectric Composites ◽

Three Phase ◽

Phase Systems ◽

Electromechanical Loading ◽

Exact Relations

Piezoelectric fibrous composites of two, three and four phases are considered. The phase boundaries are cylindrical but otherwise the microgeometry is totally arbitrary. The constituents are transversely isotropic, and exhibit pyroelectricity. Exact relations are derived between the local fields arising under a uniform electromechanical loading and a uniform temperature change in the piezoelectric composite. For given overall material symmetry, exact connections are obtained among the effective elastic, piezoelectric and dielectric constants of two- and three- phase systems. It is also shown that the effective thermal stress and pyroelectric coefficients can be expressed in terms of the effective elastic, piezoelectric, dielectric constants and constituent properties in two-, three- and four-phase composites.

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Effective Properties of Carbon Nanotube and Piezoelectric Fiber Reinforced Hybrid Smart Composites

Journal of Applied Mechanics ◽

10.1115/1.3063633 ◽

2009 ◽

Vol 76 (3) ◽

Cited By ~ 32

Author(s):

M. C. Ray ◽

R. C. Batra

Keyword(s):

Carbon Nanotubes ◽

Elastic Properties ◽

Piezoelectric Coefficient ◽

Effective Properties ◽

Single Walled Carbon Nanotubes ◽

Piezoelectric Composite ◽

Piezoelectric Composites ◽

Smart Composites ◽

Walled Carbon Nanotubes ◽

Piezoelectric Fiber

We propose a new hybrid piezoelectric composite comprised of armchair single-walled carbon nanotubes and piezoelectric fibers as reinforcements embedded in a conventional polymer matrix. Effective piezoelectric and elastic properties of this composite have been determined by a micromechanical analysis. Values of the effective piezoelectric coefficient e31 of this composite that accounts for the in-plane actuation and of effective elastic properties are found to be significantly higher than those of the existing 1–3 piezoelectric composites without reinforced with carbon nanotubes.

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An analysis of piezoelectric composite materials containing ellipsoidal inhomogeneities

Proceedings of the Royal Society of London. Series A: Mathematical and Physical Sciences ◽

10.1098/rspa.1993.0145 ◽

1993 ◽

Vol 443 (1918) ◽

pp. 265-287 ◽

Cited By ~ 185

Keyword(s):

Composite Materials ◽

Effective Properties ◽

Mean Field ◽

Piezoelectric Medium ◽

Piezoelectric Composite ◽

High Concentration ◽

Reinforced Composite ◽

The Matrix ◽

Eshelby’S Tensor ◽

Piezoelectric Solids

A set of four tensors corresponding to Eshelby’s tensor in elasticity are obtained for an ellipsoidal inclusion embedded in an infinite piezoelectric medium. These tensors, which describe the elastic, piezoelectric, and dielectric constraint of the matrix, are obtained from W. F. Deeg’s solution to inclusion and inhomogeneity problems in piezoelectric solids. These tensors are then used as the backbone in the development of a micromechanics theory to predict the effective elastic, dielectric, and piezoelectric moduli of particle and fibre reinforced composite materials. The effects of interaction among inhomogeneities at finite concentrations are approximated through the Mori-Tanaka mean field approach. This approach, although widely utilized in the study of uncoupled elastic and dielectric behaviour, has not before been applied to the study of coupled behaviour. To help ensure confidence in the theory, the analytical predictions are proven to be self-consistent, diagonally symmetric, and to exhibit the correct behaviour in the low and high concentration limits. Finally, numerical results are presented to illustrate the effects of the concentration, shape, and material properties of the reinforcement on the effective properties of piezoelectric composites and analytical predictions are shown to result in good agreement with existing experimental data.

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