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

2009 ◽  
Vol 76 (3) ◽  
Author(s):  
M. C. Ray ◽  
R. C. Batra

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.

Author(s):  
Kepin Kavathia ◽  
Manoj Settipalli ◽  
Samikkannu Raja

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.


2016 ◽  
Vol 30 (08) ◽  
pp. 1650118 ◽  
Author(s):  
Igor K. Petrushenko ◽  
Konstantin B. Petrushenko

The structural and elastic properties of neutral and ionized dichlorocarbene (CCl2) functionalized single-walled carbon nanotubes (SWCNTs) were studied using density functional theory (DFT). The Young’s modulus of ionized pristine SWCNTs is found to decrease in comparison to that of neutral models. The interesting effect of increase in Young’s modulus values of ionized functionalized SWCNTs is observed. We ascribe this feature to the concurrent processes of the bond elongation on ionization and the local deformation on cycloaddition. The strong dependence of the elasticity modulus on the number of addends is also observed. However, the CCl2-attached SWCNTs in their neutral and ionized forms remain strong enough to be suitable for the reinforcement of composites. In contrast to the elastic properties, the binding energies do not change significantly, irrespective of CCl2 coverage.


Carbon ◽  
2004 ◽  
Vol 42 (1) ◽  
pp. 39-45 ◽  
Author(s):  
Toshiaki Natsuki ◽  
Kriengkamol Tantrakarn ◽  
Morinobu Endo

Author(s):  
X. Song ◽  
Q. Ge ◽  
S.-C. Yen

A first principles approach has been employed to study the elastic properties of ten zigzag and seven armchair types of single-walled carbon nanotubes (SWNTs) with the diameter varied from 0.551 to 1.358 nm. The linear elastic behavior of the SWNTs when subject to small deformation is studied by four virtual mechanical experiments: uniaxial strain, uniaxial stress, in-plane pure shear, and in-plane bi-axial tension tests. Assuming that a SWNT be transversely isotropic, a strain energy approach is used to calculate the Young’s moduli in axial and transverse directions, major Posson’s ratio, plain strain bulk, and in-plane shear moduli of the carbon nanotubes. It is found that the elastic constants are insensitive to the tube size, but show a slight dependence upon the helicity. However, the differences in the elastic moduli between zigzag and armchair nanotubes are within 10%.


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