scholarly journals EFFECTS OF INTERPHASE AND MATRIX PROPERTIES ON EFFECTIVE TENSILE ELASTIC MODULUS OF CARBON NANOTUBE-BASED COMPOSITE

1970 ◽  
Vol 40 (1) ◽  
pp. 29-38 ◽  
Author(s):  
AKM Masud ◽  
Nabila Tahreen ◽  
Farhana Abedin
Keyword(s):  
Elastic Modulus ◽  
Carbon Nanotube ◽  
Elasticity Theory ◽  
Numerical Solutions ◽  
Volume Fraction ◽  
The Finite Element Method ◽  
Property Variation ◽  
Matrix Properties ◽  
Matrix Property ◽  
Tensile Elastic Modulus

The aim of this research is to assess the effects of interphase property and matrix property on the tensile elastic modulus (TEM) of the carbon nanotube (CNT) using a 3-D nanoscale representative volume element (RVE) based on continuum mechanics and using the finite element method (FEM). Formulas to extract the effective material constants from solutions for the RVE is derived based on the elasticity theory. Based on the strength of materials theory, an extended rule of mixtures, for estimating the effective Young's modulus, is applied for comparisons with the numerical solutions based on the elasticity theory. Both long and short CNT embedded in matrix at a volume fraction of 2% and 5% respectively is considered for investigating the effects of interphase and matrix property variation. The results demonstrate that in both the cases, matrix property and interphase property significantly influence the TEM of the CNT based composite. These results suggest that a coating of harder polymer on the CNT or a surface treatment can significantly increase the TEM of CNT based composite. Keywords: Carbon nanotube, Nanocomposites, Interphase, Tensile elastic modulus, FEM.   doi: 10.3329/jme.v40i1.3471   Journal of Mechanical Engineering, Vol. ME40, No. 1, June 2009 29-38

Effect of Fiber Diameter Waviness and Wavelength Ratio on the Effective Tensile Elastic Modulus of Carbon Nanotube-Based Polymer Composites

2009 ◽  
Vol 83-86 ◽  
pp. 473-480
Author(s):  
A.A. Khaled ◽  
A.K.M. Masud ◽  
S.C. Chowdhury ◽  
S. Jannat ◽  
M. Obayedullah
Keyword(s):  
Elastic Modulus ◽  
Carbon Nanotube ◽  
Polymer Composites ◽  
Polymer Composite ◽  
Volume Fraction ◽  
Fiber Diameter ◽  
Material Constant ◽  
Diameter Variation ◽  
Ratio Variation ◽  
Tensile Elastic Modulus

In this paper, the effects of nanotube diameter, waviness ratio and wavelength ratio on the tensile elastic modulus (TEM) of the carbon nanotube (CNT) reinforced polymer composites is investigated using a 3-D nanoscale representative volume element (RVE) based on continuum mechanics and using the finite element method (FEM). Formula to extract the effective material constant from solutions for the RVE under axial loading is derived based on the elasticity theory. Both long and short CNT embedded in the matrix are considered for investigating the effect of fiber diameter variation whereas only long wavy CNT is considered for investigating the effect of waviness and wavelength ratio variation, all at a volume fraction of 5%. First, the effects of CNT diameter on the TEM of the composite are investigated. Numerical results show that TEM of the polymer composite is influenced by tube diameter variation for both long and short CNT. Then the effects of waviness ratio and wavelength ratio on the TEM of polymer composite are investigated. Results show that both the waviness and wavelength ratio variation of CNT significantly influence the TEM of the polymer composite.

A Theoretical Formula for the Validity Limits of the Dipole Approximation for a Dielectric Mixture

2014 ◽  
Vol 906 ◽  
pp. 72-80
Author(s):  
Chang He Yang ◽  
Ding Long Cao ◽  
Lin Song Guo
Keyword(s):  
Finite Element Method ◽  
Numerical Solutions ◽  
Volume Fraction ◽  
Dipole Approximation ◽  
Empirical Method ◽  
Theoretical Formula ◽  
The Finite Element Method ◽  
Dielectric Mixture ◽  
Good Agreement ◽  
Dielectric Mismatch

A newly criterion for the validity limits of the dipole approximation for a dielectric mixture was presented, based on the comparison between the dipole approximation and the numerical solutions by the finite-element method (FEM). In terms of this criterion and the dipole-enhanced model, a simple theoretical formula for the validity limits was derived. This formula includes three variables: the dielectric mismatch, the volume fraction of particles and the precision. Its calculated results have a good agreement with the limits determined by the empirical method in the range of our interest, which indicates the theoretical formula is creditable. Using this formula, we can approximate the precision of the dipole approximation for an arbitrary dielectric mixture. And we found that the dipole approximation is acceptable with the precision equal to 30% when the dielectric mismatch is less than 2.3 (εi/ εe2.3) for the almost touching spheres.

scholarly journals Effects of Heat Generation/Absorption on a Stagnation Point Flow Past a Stretching Sheet Carbon Nanotube Water-Based Hybrid Nanofluid with Newtonian Heating

2021 ◽  
Vol 6 (2) ◽  
pp. 34-47
Author(s):  
Abdul Muiz Mohd Zaki ◽  
Nurul Farahain Mohammad ◽  
Siti Khuzaimah Soid ◽  
Muhammad Khairul Anuar Mohamed ◽  
Rahimah Jusoh
Keyword(s):  
Heat Transfer ◽  
Carbon Nanotube ◽  
Stagnation Point ◽  
Heat Generation ◽  
Stretching Sheet ◽  
Numerical Solutions ◽  
Volume Fraction ◽  
Hybrid Nanoparticles ◽  
Hybrid Nanofluid ◽  
Newtonian Heating

This study investigates the mathematical modelling of heat generation/absorption effect on the convective flow of single wall carbon nanotube-copper (SWCNT-Cu)/water hybrid nanofluid towards a stagnation point past a stretching sheet with Newtonian heating. The set of governing equations in the form of non-linear partial differential equations are first transform using the similarity transformation technique then solved numerically by the Runge-Kutta-Fehlberg (RKF45) method in Maple software. The numerical solutions were obtained for the surface temperature, the heat transfer coefficient and the skin friction coefficient as well as the velocity and the temperature profiles. The features of the flow and heat transfer characteristics for various values of the stretching parameter, the conjugate parameter, the nanoparticle volume fraction parameter and the heat source/sink parameter are analyzed and discussed. It is found that effects of hybrid nanoparticles are more significant for lower stretching parameter and for large conjugate parameter values, as well as the heat generation/absorption.

Thermal Modeling of Randomly Distributed Multi-Walled Carbon Nanotube/Polymer Composites

2012 ◽  
Vol 548 ◽  
pp. 123-127
Author(s):  
Xiao Tuo Li ◽  
Xin Yu Fan ◽  
Ying Dan Zhu ◽  
Juan Li
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotube ◽  
Thermal Resistance ◽  
Polymer Composites ◽  
Volume Fraction ◽  
Three Dimensional ◽  
Interfacial Thermal Resistance ◽  
The Finite Element Method ◽  
Multi Walled Carbon Nanotube ◽  
The Relationship

A three-dimensional computational model based on the finite element method was developed to predict the thermal properties of randomly distributed multi-walled carbon nanotube (MWCNT)/polymer composites. The numerical results agree very well with the experimental data for MWCNT/epoxy composites with the MWCNT loading below ~10 vol% at the interfacial thermal resistance of ~1.0×10-8 m2K/W, which may give insight into the relationship between the thermal behavior of MWCNT-matrix interfaces and the thermal conductivity of composites. This model is also a useful tool to evaluate the effects of MWCNT-matrix interfacial thermal resistance, volume fraction, thermal conductivity and diameter of MWCNTs on the thermal conductivity of other types of MWCNT/ polymer composites.

scholarly journals On the computational modelling of nonlinear electro-elasticity in heterogeneous bodies at finite deformations

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Anas Kanan ◽  
Michael Kaliske
Keyword(s):  
Mechanical Properties ◽  
Finite Element Method ◽  
Finite Element ◽  
Numerical Solutions ◽  
Volume Fraction ◽  
Material Model ◽  
Electric Response ◽  
Tube Model ◽  
The Finite Element Method ◽  
Element Method

AbstractDielectric elastomer actuators (DEA) have been demonstrated to exhibit a quasi-immediate electro-mechanical actuation response with relatively large deformation capability. The properties of DEA make them suitable to be used in the form of major active components within soft robotics and biomimetic artificial muscles. However, some of the electro-active material properties impose limitations on its applications. Therefore, researchers attempt to modify the structure of the homogeneous DEA material by the incorporation of fillers that possess distinct electro-mechanical properties. This modification of the material’s structure leads to a fabricated inhomogeneous composite. From the point of mathematical material modelling and numerical simulation, we propose a material model and a computational framework using the finite element method, which is capable of emulating nonlinear electro-elastic interactions. We consider a coupled electro-mechanical description with the electric and the electro-mechanical properties of the material assumed to be nonlinearly dependent on the deformation. Furthermore, we demonstrate a coupled ansatz that expresses the electric response as dielectrically quasi-linear with only density-dependent electric permittivity. We couple the electro-mechanical models to the extended tube model, which is a suitable approach for the realistic emulation of the hyperelastic response of rubber-like materials. Thereafter, we demonstrate analytical and numerical solutions of a homogeneous electro-elastic body with the Neo-Hookean material model and the extended tube model to express the hyperelastic response. Finally, we use the finite element method to investigate several heterogeneous configurations consisting of soft DEA matrix filled with spherical stiff inclusions with changing volume fraction and ellipsoidal inclusions with varying aspect ratio.

scholarly journals Comparative study of elastic properties and mode I fracture energy of carbon nanotube/epoxy and carbon fibre/epoxy laminated composites

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Jyotikalpa Bora ◽  
Sushen Kirtania
Keyword(s):  
Carbon Nanotube ◽  
Carbon Fibre ◽  
Fracture Energy ◽  
Elastic Properties ◽  
Volume Fraction ◽  
Laminated Composites ◽  
Laminated Composite ◽  
Fe Analysis ◽  
Mode I ◽  
Mode I Fracture

Abstract A comparative study of elastic properties and mode I fracture energy has been presented between conventional carbon fibre (CF)/epoxy and advanced carbon nanotube (CNT)/epoxy laminated composite materials. The volume fraction of CNT fibres has been considered as 15%, 30%, and 60% whereas; the volume fraction of CF has been kept constant at 60%. Three stacking sequences of the laminates viz.[0/0/0/0], [0/90/0/90] and [0/30/–30/90] have been considered in the present analysis. Periodic microstructure model has been used to calculate the elastic properties of the laminated composites. It has been observed analytically that the addition of only 15% CNT in epoxy will give almost the same value of longitudinal Young’s modulus as compared to the addition of 60% CF in epoxy. Finite element (FE) analysis of double cantilever beam specimens made from laminated composite has also been performed. It has been observed from FE analysis that the addition of 15% CNT in epoxy will also give almost the same value of mode I fracture energy as compared to the addition of 60% CF in epoxy. The value of mode I fracture energy for [0/0/0/0] laminated composite is two times higher than the other two types of laminated composites.

scholarly journals A numerical frame work of magnetically driven Powell-Eyring nanofluid using single phase model

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Wasim Jamshed ◽  
Mohamed R. Eid ◽  
Kottakkaran Sooppy Nisar ◽  
Nor Ain Azeany Mohd Nasir ◽  
Abhilash Edacherian ◽  
...  
Keyword(s):  
Differential Equations ◽  
Numerical Solutions ◽  
Volume Fraction ◽  
Dissipative Flow ◽  
Uniform Medium ◽  
Heat Transport Properties ◽  
Flow Heat ◽  
Frame Work ◽  
Slippery Surface ◽  
Nanoparticle Shapes

AbstractThe current investigation aims to examine heat transfer as well as entropy generation analysis of Powell-Eyring nanofluid moving over a linearly expandable non-uniform medium. The nanofluid is investigated in terms of heat transport properties subjected to a convectively heated slippery surface. The effect of a magnetic field, porous medium, radiative flux, nanoparticle shapes, viscous dissipative flow, heat source, and Joule heating are also included in this analysis. The modeled equations regarding flow phenomenon are presented in the form of partial-differential equations (PDEs). Keller-box technique is utilized to detect the numerical solutions of modeled equations transformed into ordinary-differential equations (ODEs) via suitable similarity conversions. Two different nanofluids, Copper-methanol (Cu-MeOH) as well as Graphene oxide-methanol (GO-MeOH) have been taken for our study. Substantial results in terms of sundry variables against heat, frictional force, Nusselt number, and entropy production are elaborate graphically. This work’s noteworthy conclusion is that the thermal conductivity in Powell-Eyring phenomena steadily increases in contrast to classical liquid. The system’s entropy escalates in the case of volume fraction of nanoparticles, material parameters, and thermal radiation. The shape factor is more significant and it has a very clear effect on entropy rate in the case of GO-MeOH nanofluid than Cu-MeOH nanofluid.

Static and Free Vibration Analyses of Functionally Graded Carbon Nanotube Reinforced Composite Plates using CS-DSG3

2019 ◽  
Vol 17 (03) ◽  
pp. 1850133 ◽  
Author(s):  
T. Truong-Thi ◽  
T. Vo-Duy ◽  
V. Ho-Huu ◽  
T. Nguyen-Thoi
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Free Vibration ◽  
Numerical Solutions ◽  
Composite Plates ◽  
Functionally Graded ◽  
Triangular Element ◽  
Reinforced Composite ◽  
Strain Smoothing ◽  
Discrete Shear Gap

This study presents an extension of the cell-based smoothed discrete shear gap method (CS-DSG3) using three-node triangular elements for the static and free vibration analyses of carbon nanotube reinforced composite (CNTRC) plates. The single-walled carbon nanotubes (SWCNTs) are assumed to be uniformly distributed (UD) and functionally graded (FG) distributed along the thickness direction. The material properties of carbon nanotube-reinforced composite plates are estimated according to the rule of mixture. The governing equations are developed based on the first-order shear deformation plate theory (FSDT). In the CS-DSG3, each triangular element will be divided into three sub-triangles, and in each sub-triangle, the stabilized discrete shear gap method is used to compute the strains and to avoid the transverse shear locking. Then the strain smoothing technique on the whole triangular element is used to smooth the strains on these three sub-triangles. Effects of several parameters, such as the different distribution of carbon nanotubes (CNTs), nanotube volume fraction, boundary condition and width-to-thickness ratio of plates are investigated. In addition, the effect of various orientation angles of CNTs is also examined in detail. The accuracy and reliability of the proposed method are verified by comparing its numerical solutions with those of other available results in the literature.

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