scholarly journals Development of Expanded Takayanagi Model for Tensile Modulus of Carbon Nanotubes Reinforced Nanocomposites Assuming Interphase Regions Surrounding the Dispersed and Networked Nanoparticles

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 233 ◽  
Author(s):  
Yasser Zare ◽  
Kyong Yop Rhee
Keyword(s):  
Carbon Nanotubes ◽  
Volume Fraction ◽  
Tensile Modulus ◽  
Experimental Results ◽  
Volume Fractions ◽  
Interphase Region ◽  
Acceptable Agreement ◽  
Network Modulus ◽  
Neat Matrix

In this paper, we consider the interphase regions surrounding the dispersed and networked carbon nanotubes (CNT) to develop and simplify the expanded Takayanagi model for tensile modulus of polymer CNT nanocomposites (PCNT). The moduli and volume fractions of dispersed and networked CNT and the surrounding interphase regions are considered. Since the modulus of interphase region around the dispersed CNT insignificantly changes the modulus of nanocomposites, this parameter is removed from the developed model. The developed model shows acceptable agreement with the experimental results of several samples. “ER” as nanocomposite modulus per the modulus of neat matrix changes from 1.4 to 7.7 at dissimilar levels of “f” (CNT fraction in the network) and network modulus. Moreover, the lowest relative modulus of 2.2 is observed at the smallest levels of interphase volume fraction ( ϕ i < 0.017), while the highest “ ϕ i ” as 0.07 obtains the highest relative modulus of 11.8. Also, the variation of CNT size (radius and length) significantly changes the relative modulus from 2 to 20.

scholarly journals A Micro-mechanical Investigation of Empirical Models for the Effective Properties of Aligned Short-Fibre Composites

1995 ◽  
Vol 4 (1) ◽  
pp. 096369359500400
Author(s):  
T.D. Papathanasiou
Keyword(s):  
Aspect Ratio ◽  
Volume Fraction ◽  
Tensile Modulus ◽  
Fibre Volume ◽  
Short Fibre ◽  
Computational Results ◽  
Volume Fractions ◽  
Fibre Composites ◽  
Effective Tensile Modulus ◽  
Fibre Aspect Ratio

The predictions of the Halpin equation concerning the effect of fibre volume fraction and fibre aspect ratio on the effective tensile modulus of uniaxially aligned short-fibre composites are compared with computational experiments on three-dimensional, multiparticle composite samples. The method of boundary elements is used to model the mechanical behaviour of composite specimens consisting of up to 40 discrete aligned fibres randomly dispersed in an elastic matrix. Statistical averages of computational results relating the effective tensile modulus to the aspect ratio and volume fraction of the fibres are found to agree very well with the predictions of the Halpin equation for fibre aspect ratio up to 10 and fibre volume fractions up to 20%. Computational results seem to indicate that the predictions of the Halpin equation fall bellow those of micro-mechanical models at higher volume fractions.

Interphase influences on the mechanical behavior of carbon nanotube–shape memory polymer nanocomposites: A micromechanical approach

2018 ◽  
Vol 30 (3) ◽  
pp. 463-478 ◽  
Author(s):  
MK Hassanzadeh-Aghdam ◽  
MJ Mahmoodi ◽  
R Ansari ◽  
A Darvizeh
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Shape Memory ◽  
Polymer Nanocomposites ◽  
Elastic Moduli ◽  
Volume Fraction ◽  
Shape Memory Polymer ◽  
Micromechanical Model ◽  
Elastic Behavior ◽  
Interphase Region

The effects of interphase characteristics on the elastic behavior of randomly dispersed carbon nanotube–reinforced shape memory polymer nanocomposites are investigated using a three-dimensional unit cell–based micromechanical method. The interphase region is formed due to non-bonded van der Waals interaction between a carbon nanotube and a shape memory polymer. The influences of temperature, diameter, volume fraction, and arrangement type of carbon nanotubes within the matrix as well as two interphase factors, including adhesion exponent and thickness on the carbon nanotube/shape memory polymer nanocomposite’s longitudinal and transverse elastic moduli, are explored extensively. Moreover, the results are presented for the shape memory polymer nanocomposites containing randomly oriented carbon nanotubes. The obtained results clearly demonstrate that the interphase region plays a crucial role in the modeling of the carbon nanotube/shape memory polymer nanocomposite’s elastic moduli. It is observed that the nanocomposite’s elastic moduli remarkably increase with increasing interphase thickness or decreasing adhesion exponent. It is found that when the interphase is considered in the micromechanical simulation, the shape memory polymer nanocomposite’s elastic moduli non-linearly increase as the carbon nanotube diameter decreases. The predictions of the present micromechanical model are compared with those of other analytical methods and available experiments.

Experimental Research Regarding the Tensile Properties of some Polypropylene Based Biocomposites Reinforced with Hemp Shives

2013 ◽  
Vol 814 ◽  
pp. 230-234
Author(s):  
Maria Silvia Pernevan ◽  
Liviu Marşavina ◽  
Ioan Pernevan ◽  
Cecilia Sîrghie ◽  
Mihaela Popescu
Keyword(s):  
Tensile Strength ◽  
Tensile Properties ◽  
Experimental Research ◽  
Volume Fraction ◽  
Tensile Modulus ◽  
Tensile Behavior ◽  
Point Of View ◽  
New Materials ◽  
Volume Fractions ◽  
Recyclable Resources

The paper analyzes the tensile behavior of some new biocomposite materials based on polypropylene reinforced with hemp shives for different volume fractions and sizes. The aim of this study is to make a comparison between the tensile properties of these materials and to determine in which way the values of the tensile strength and tensile modulus are influenced by the volume fraction and dimensions of the reinforcement elements. The analyzed materials are new materials based on renewable and recyclable resources and from this point of view these materials have a less harmful impact on the environment compared to the conventional composites. By analyzing the tensile properties of polyproylene based biocomposites reinforced with hemp shives it can be observed in which way these materials could replace conventional materials in various fields of applications.

3D waviness effect of carbon nanotubes on fundamental natural frequency and modeling of resonance of nanocomposite structure

2021 ◽  
Author(s):  
Narendra Kumar Jha ◽  
Santosh Kumar ◽  
Srihari Dodla
Keyword(s):  
Carbon Nanotubes ◽  
Natural Frequency ◽  
Composite Beam ◽  
Volume Fraction ◽  
Mode Shapes ◽  
Fe Model ◽  
Vibratory System ◽  
Single Wave ◽  
Fundamental Natural Frequency ◽  
Neat Matrix

Optimum waviness of carbon nanotubes (CNTs) inside a matrix composite beam and composite bridge is endeavor to obtain its utmost natural frequencies considering a volume fraction of CNTs. 3D FE model of the beam is generated via ABAQUS along with Python programming and thereafter to calculate an optimal waviness under encastre boundary conditions and different vibration modes. The effect of waviness and the number of waves on mode shapes, natural frequency, and corresponding stiffness of a beam are examined, and the outcomes are compared to those of a pure polymer beam, straight CNT-based composite beam and nanobridge value. It was decided to conduct a convergence analysis and the optimum value of the number of elements and nodes was studied and found that 19666 nodes are reliable to give correct results. The FE analysis results reveal that the waviness effect of CNTs significantly depends on mode shapes. The fundamental natural frequency, as well as other related vibrational properties, is observed to be enhanced. By decreasing the waviness from 50 to 25, there is an increment in natural frequency in the 3rd mode by 68.68, 5th mode by 44.6 and 6th mode by 62.4, but in other modes, there is negligible difference. When single-wave CNTs were compared, the sine wave produced more frequency in the third mode by 206.03, 4th mode by 199.8 and 6th mode by 478.6[Formula: see text]Hz. After comparing the results of different waviness types, single sine waviness, multi-waved CNTs, straight CNTs and neat matrix, it is found that for the highest value of waviness of CNT fiber-based nanocomposites, the natural frequency of CNT-reinforced nanocomposite reaches the frequency of the neat matrix and further adding of CNTs does not increase the value of frequency. The result showed that the finite element model (FEM) is a good simulation of the vibratory system.

Influence of Dispersion and Alignment of Nanotubes on the Strength and Elasticity of Carbon Nanotubes Reinforced Composites

2011 ◽  
Vol 2 (4) ◽  
Author(s):  
Unnati A. Joshi ◽  
Satish C. Sharma ◽  
S. P. Harsha
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Large Scale ◽  
Volume Fraction ◽  
Tensile Modulus ◽  
Longitudinal Direction ◽  
Design Parameters ◽  
Reinforced Composites ◽  
Element Analysis ◽  
Shear Moduli

In this paper, the effective strength and elastic properties of carbon nanotube reinforced composites are evaluated using a representative volume element with a number of carbon nanotubes embedded in the matrix. This concept is used to predict the mechanical properties of multiple, unidirectional, aligned, and also randomly dispersed carbon nanotube reinforced composites. To characterize these nanocomposites, a continuum model has been developed for large-scale analysis. The effective Young’s and shear moduli of the composites are determined using finite element analysis under the effect of elastic deformation. The role of design parameters like length and volume fraction of carbon nanotubes, tensile and shear strength as well as type of loading conditions are analyzed for multiple carbon nanotubes based composites. The discontinuous and continuous types of carbon nanotubes, with aligned and random distribution, are evaluated. The results show that the continuous and aligned carbon nanotubes produce the largest tensile modulus, compared to the discontinuous and aligned as well as discontinuous and randomly oriented carbon nanotubes along the longitudinal direction.

scholarly journals Determination of thermal conductivity of pine wood dust filled epoxy composites

2017 ◽  
Vol 21 (1 Part A) ◽  
pp. 199-210 ◽  
Author(s):  
Ramesh Mohapatra ◽  
Antaryami Mishra ◽  
Bibhuti Choudhury
Keyword(s):  
Thermal Conductivity ◽  
Volume Fraction ◽  
Maxwell Model ◽  
Theoretical Models ◽  
Experimental Results ◽  
Epoxy Composites ◽  
Dust Particles ◽  
Wood Dust ◽  
Pine Wood ◽  
Volume Fractions

In the present investigation the Thermal conductivity in particulate filler filled (Pine wood dust) epoxy composites at different volume fractions (6.5%, 11.3%,26.8% and 35.9%) have been determined experimentally by using Forced Convection apparatus. The composites of pine wood dust particles of 150 micron size have been prepared by using hand-lay-up technique. The experimental results show that the incorporation of pine wood dust results in reduction of thermal conductivity of epoxy resin and there by improves its thermal insulation capability. From the experiments it is also observed that the composite with 35.9% volume fraction of pine wood dust exhibited lowest thermal conductivity i.e 0.246 W/m-0K on comparison to 6.5%,11.3% and26.8% volume fractions. Therefore the composite with 35.9% wood dust may be more suitable for insulation application. Experimental results (22mm pipe diameter) are also compared with theoretical models such as Rule of mixture model, Maxwell model, Russell model and Baschirow & Selenew model to describe the variation of thermal conductivity versus the volume fraction of the filler. All these models exhibited results close to each other at low dust filler content. On comparison, It has been found that the errors associated with experimental (26mm Dia.) along with all the above four models with respect to experimental ones (22mm Dia.) lie in the range of 19.60 to 44.10%, 0.76 to 12.10%, 1.86 to 5.12% and 8.24 to 19.68% respectively.

Effect of Inter-Rod Coupling on 1-3 Piezocomposite High-Power Ultrasonic Transducers

2012 ◽  
Vol 476-478 ◽  
pp. 2105-2108 ◽  
Author(s):  
Yu Li Lin ◽  
Gin Shin Chen ◽  
Hsin Chih Liu ◽  
Yu Cheng Lin
Keyword(s):  
High Power ◽  
Volume Fraction ◽  
Epoxy Composite ◽  
Ultrasonic Transducer ◽  
Geometric Parameters ◽  
Experimental Results ◽  
Ultrasonic Transducers ◽  
Composite Matrix ◽  
Volume Fractions ◽  
Power Ultrasonic

Efficiency is a critical performance for a high-power ultrasonic transducer composed of 1-3 piezocomposites and geometric parameters of the composites can influence the efficiency of the transducer. The effect of inter-rod responses in the composite matrix on the efficiency was experimentally investigated in this study. For analyses, four PZT4-epoxy composite ultrasonic transducers with various volume fractions and inter-rod spacing were fabricated in-house. The experimental results demonstrated that the inter-rod coupling of the 0.1-mm spacing could significantly degrade the efficiency of the composite probe at about 1.0 MHz resonance since the 0.1-mm spacing between PZT4 rods was so small as to cause a high interference. At the same volume fraction, the transducer engineer should take the inter-rod coupling into account for the design of the high-power ultrasonic transducer.

scholarly journals Viscosity of nanofluids-A Review

2020 ◽  
Vol 7 (2) ◽  
Author(s):  
A.K. Patra ◽  
M.K. Nayak ◽  
A. Misra
Keyword(s):  
Carbon Nanotubes ◽  
Volume Fraction ◽  
Ph Value ◽  
Solid Volume Fraction ◽  
High Volume ◽  
Experimental Investigations ◽  
Fluid Viscosity ◽  
Shear Rates ◽  
Volume Fractions ◽  
Newtonian Behavior

In the present study a comprehensive review on rheological characteristics of nanofluids for their advanced heat transfer applications has been conducted and presented. The present article critically summarizes the recent research developments regarding the theoretical and experimental investigations about viscosity of different nanofluids. In addition, different reasonably attractive theoretical models and experimental correlations are explored and well discussed. Moreover, the current study analyzes several factors those strongly influencing viscosity of nanofluids include solid volume fraction, temperature, particle size, particle shape, different base fluids, surfactants addition, ultrasonication, nanoclustering and pH value. Important theoretical and experimental results from many researchers and predictions from a number of viscosity models are compared and discussed with appropriate justification. Most results reveal that the viscosity of nanofluid upsurges due to an increase in particle concentration while that belittles with diminishing temperature. Augmentation of nano-additives size leads to decreasing/increasing of nanofluid fluid viscosity. For the most nanofluids, Newtonian behavior is observed for low volume fractions, shear rates, concentrations and viscosity while non-Newtonian behavior is visualized for high volume fractions, shear rates, concentrations and viscosity. Nanofluids used carbon nanotubes are almost non-Newtonian in nature while nanofluids not involving carbon nanotubes are mostly Newtonian. Finally, the research challenges and needs in this important area of nanofluids are also highlighted.

scholarly journals Analysis of the Connecting Effectiveness of the Interphase Zone on the Tensile Properties of Carbon Nanotubes (CNT) Reinforced Nanocomposite

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 896 ◽  
Author(s):  
Yasser Zare ◽  
Kyong Yop Rhee
Keyword(s):  
Carbon Nanotubes ◽  
Tensile Properties ◽  
Polymer Nanocomposites ◽  
Simulation Study ◽  
Tensile Modulus ◽  
Excluded Volume ◽  
Interphase Region ◽  
Important Character

The establishment of interphase region around nanoparticles accelerates the percolating of carbon nanotubes (CNT) in polymer nanocomposites reinforced with CNT (PCNT), due to the linking productivity of interphase district before the physical connecting of nanoparticles. Therefore, the interphase is an important character in the networks of CNT in PCNT. Here, a simulation study is presented to investigate the interphase connection in the mechanical possessions of PCNT including tensile modulus and strength. A number of models comprising Takayanagi, Ouali, Pukanszky and Callister are developed by the assumption of an interphase district in the CNT excluded volume. The advanced models depict the optimistic influences of reedy and lengthy CNT besides dense interphase on the stiffness and tensile power of nanocomposites. The Pukanszky calculations depict that the interphase strength plays a more noteworthy role in the nanocomposites strength compared to the CNT length.

Influence of Multiwall Carbon Nanotube on mechanical and wear properties of Copper – Iron composite

2020 ◽  
Vol 17 (1) ◽  
pp. 7570-7576 ◽  
Author(s):  
H. Sh. Hammood ◽  
S. S. Irhayyim ◽  
A. Y. Awad ◽  
H. A. Abdulhadi
Keyword(s):  
Carbon Nanotubes ◽  
Volume Fraction ◽  
Hybrid Composites ◽  
Hydraulic Press ◽  
Dry Sliding Wear ◽  
Multiwall Carbon Nanotube ◽  
Wear Properties ◽  
Sem Images ◽  
Wear Rates ◽  
Multiwall Carbon

Multiwall Carbon nanotubes (MWCNTs) are frequently attractive due to their novel physical and chemical characteristics, as well as their larger aspect ratio and higher conductivity. Therefore, MWCNTs can allow tremendous possibilities for the improvement of the necessarily unique composite materials system. The present work deals with the fabrication of Cu-Fe/CNTs hybrid composites manufactured by powder metallurgy techniques. Copper powder with 10 vol. % of iron powder and different volume fractions of Multi-Wall Carbon Nanotubes (MWCNTs) were mixed to get hybrid composites. The hybrid composites were fabricated by adding 0.3, 0.6, 0.9, and 1.2 vol.% of MWCNTs to Cu- 10% Fe mixture using a mechanical mixer. The samples were compressed under a load of 700 MPa using a hydraulic press to compact the samples. Sintering was done at 900°C for 2 h at 5ºC/min heating rate. The microscopic structure was studied using a Scanning Electron Microscope (SEM). The effect of CNTs on the mechanical and wear properties, such as micro-hardness, dry sliding wear, density, and porosity were studied in detail. The wear tests were carried out at a fixed time of 20 minutes while the applied loads were varied (5, 10, 15, and 20 N). SEM images revealed that CNTs were uniformly distributed with relative agglomeration within the Cu/Fe matrix. The results showed that the hardness, density, and wear rates decreased while the percentage of porosity increased with increasing the CNT volume fraction. Furthermore, the wear rate for all the CNTs contents increased with the applied load.

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