A new micromechanics approach for predicting the elastic response of polymer nanocomposites reinforced with randomly oriented and distributed wavy carbon nanotubes

2017 ◽  
Vol 51 (20) ◽  
pp. 2899-2912 ◽  
Author(s):  
MK Hassanzadeh-Aghdam ◽  
R Ansari ◽  
A Darvizeh
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Polymer Nanocomposites ◽  
Random Distribution ◽  
Volume Fraction ◽  
Unit Cell ◽  
Elastic Behavior ◽  
Random Orientation ◽  
Reinforced Polymer ◽  
The Matrix

A comprehensive investigation is carried out into the elastic behavior of carbon nanotube-reinforced polymer nanocomposites using two combined analytical micromechanical methods. A unit cell-based micromechanical method is developed to model the random distribution of carbon nanotubes within the polymer matrix. Also, the Eshelby method is used for modeling the random orientation state of carbon nanotubes within the matrix. Two fundamental aspects affecting the mechanical behavior of carbon nanotube/polymer nanocomposites, including the carbon nanotube waviness and the interphase formed due to the non-boned interaction between the carbon nanotube and the surrounding polymer, are considered in the unit cell method. Comparisons between the results of present method and experimental data reveal that for more realistic predictions, five important factors including, random orientation and random distribution of carbon nanotubes, interphase, waviness and transversely isotropic behavior of carbon nanotube should be considered in the modeling of carbon nanotube-reinforced polymer nanocomposites. The effects of volume fraction, number of waves and waviness factor of carbon nanotube as well as the type of random distribution of CNTs within the matrix on the elastic modulus of the polymer nanocomposites are studied.

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.

Dynamic Buckling of Thermo-Electro-Mechanically Loaded FG-CNTRC Beams

2015 ◽  
Vol 15 (08) ◽  
pp. 1540017 ◽  
Author(s):  
Jie Yang ◽  
Liao-Liang Ke ◽  
Chuang Feng
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Applied Voltage ◽  
Volume Fraction ◽  
Beam Theory ◽  
Distribution Patterns ◽  
Dynamic Buckling ◽  
Functionally Graded ◽  
Periodic Force ◽  
The Matrix

Functionally graded carbon nanotube reinforced nanocomposites have drawn great attention in both research and engineering communities. The weak interfacial bonding between carbon nanotubes and the matrix, which traditionally hinders the application of carbon nanotube reinforced nanocomposites, can be remarkably improved through the graded distribution of carbon nanotubes in the matrix. Within the framework of classical beam theory, this paper investigates the dynamic buckling behavior of functionally graded nanocomposite beams reinforced by single-walled carbon nanotubes and integrated with two surface bonded piezoelectric layers. The governing equations of the beam subjected to an applied voltage, a uniform temperature and an axial periodic force are derived by applying Hamilton's principle. Numerical results are presented for beams with different distribution patterns and volume fractions of carbon nanotubes and end support conditions. The influences of the beam geometry, temperature change, applied voltage, static axial force component, boundary condition, carbon nanotube volume fraction and its distribution on the unstable regions of FG-CNTRC piezoelectric beams are discussed in detail.

Stress Analysis of Carbon Nanotubes Reinforced Nanocomposites

2013 ◽  
Vol 284-287 ◽  
pp. 357-361
Author(s):  
Shiuh Chuan Her ◽  
Shou Jan Liu
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Stress Analysis ◽  
Volume Fraction ◽  
Interfacial Shear Stress ◽  
Stress Transfer ◽  
Large Volume Fraction ◽  
Concentric Cylinders ◽  
The Matrix ◽  
Lag Model

Stress transfer in the carbon nanotube reinforced nanocomposites is investigated in this work. The model consists of two concentric cylinders, namely, a single-walled carbon nanotube cylinder (SWCNT) and a matrix cylinder, as the representative volume element (RVE). The stress analysis is performed using the shear lag model for the axisymmetric RVE. Analytical solutions for the axial normal stresses in the SWCNT and matrix, and the interfacial shear stress across the SWCNT/matrix interface are obtained. Numerical results show that using a large volume fraction improves the efficiency of the stress transfer from the matrix to the carbon nanotubes.

scholarly journals Effect of Temperature on the Viscoelastic Properties of Carbon Nanotube Reinforced Polypropylene Composites

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Jun Huang ◽  
Denis Rodrigue ◽  
Ling Dong
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Stress Distribution ◽  
Viscoelastic Properties ◽  
Volume Fraction ◽  
Axial Direction ◽  
Effect Of Temperature ◽  
Polypropylene Composites ◽  
The Matrix

Finite element method (FEM) is used to analyze the mechanical properties of carbon nanotubes (CNTs) reinforced polypropylene (PP) composites. Firstly, polypropylene is assumed as a viscoelastic material, while carbon nanotubes are assumed as linear elastic materials to study the effect of temperature on the mechanical properties of neat PP and CNT/PP nanocomposites. Secondly, to compare the viscoelastic properties of neat PP and CNT/PP nanocomposites, the relaxation time at a specific temperature is used to investigate the relaxation of the nanocomposites for fixed tensile displacements. Thirdly, the effect of CNT volume fraction on the viscoelastic properties of nanocomposites is studied at different temperatures. Finally, to better understand the stress distribution along the CNT axial direction, a single carbon nanotube is isolated in the matrix to compare the stress distribution with nonisolated CNTs.

scholarly journals Recent Advances in Characterization Techniques for the Interface in Carbon Nanotube-Reinforced Polymer Nanocomposites

2019 ◽  
Vol 2019 ◽  
pp. 1-24 ◽  
Author(s):  
Junjie Chen ◽  
Xuhui Gao ◽  
Deguang Xu
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Polymer Nanocomposites ◽  
Mechanical And Thermal Properties ◽  
Characterization Techniques ◽  
Current State ◽  
Reinforced Polymer ◽  
Emerging Trends ◽  
Functionalization Of Carbon Nanotubes ◽  
Physical And Chemical

The current state of characterization techniques for the interface in carbon nanotube-reinforced polymer nanocomposites is reviewed. Different types of interfaces that exist within the nanocomposites are summarized, and current efforts focused on understanding the interfacial properties and interactions are reviewed. The emerging trends in characterization techniques and methodologies for the interface are presented, and their strengths and limitations are summarized. The intrinsic mechanism of the interactions at the interface between the carbon nanotubes and the polymer matrix is discussed. Special attention is given to research efforts focused on chemical functionalization of carbon nanotubes. The benefits and disadvantages associated with covalent and noncovalent functionalization methods are evaluated, respectively. Various techniques used to characterize the properties of the interface are extensively reviewed. How the mechanical and thermal properties of the nanocomposites depend on the physical and chemical nature of the interface is also discussed. Better understanding and design of the interface at the atomic level could become the forefront of research in the polymer community. Potential problems going to be solved are finally highlighted.

COMPUTATIONAL DESCRIPTION OF THE GEOMETRY OF ALIGNED CARBON NANOTUBES IN POLYMER NANOCOMPOSITES

2021 ◽  
Author(s):  
STEPAN V. LOMOV ◽  
JEONYOON LEEJEONYOON LEE ◽  
BRIAN L. WARDLE ◽  
NIKITA A. GUDKOV ◽  
ISKANDER S. AKHATOV ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Polymer Nanocomposites ◽  
Finite Element Modelling ◽  
Volume Fraction ◽  
Voronoi Tessellation ◽  
Geometrical Model ◽  
Limiting Factor ◽  
Full Paper ◽  
Aligned Carbon Nanotubes ◽  
Curvature And Torsion

The paper considers nanocomposites, reinforced with aligned carbon nanotubes (A- CNTs). Nominally aligned, the CNTs in the forest are wavy, which has important consequences in downgraded mechanical properties, and influences electric and thermal performance. The most detailed geometrical model of A-CNTs was proposed by Stein and Wardle (Nanotechnology, 27:035701, 2015). It creates a centerline trajectory of a CNT in steps, each step defining a section of the CNT, growing in the alignment direction with certain deviations. The paper, starting from this framework, formulates a model of the CNT geometry, which is based on the concept of correlation length of the CNT waviness and maximum admissible CNT curvature and torsion. The value of the maximum curvature can be linked to the buckling criteria for CNTs, or derived from ab initio and finite element modelling. It is used as a limiting factor for the growth, defining the waviness and tortuosity of the CNTs. The CNTs in the forest are placed in a random non-regular way, using Voronoi tessellation. The full paper includes investigation of the proposed algorithm for several values of the CNT volume fraction (in the range 0.5%…8%), the dependency of the modelled geometry on the curvature, and the apparent twist of the CNT centerlines. The modelling results are compared with experimental observations in 3D TEM imaging.

A Carbon Nanotubes Aggregation in Polymer Nanocomposites

2018 ◽  
Vol 935 ◽  
pp. 55-60 ◽  
Author(s):  
Louise B. Atlukhanova ◽  
George V. Kozlov
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Polymer Nanocomposites ◽  
Packing Density ◽  
Elasticity Modulus ◽  
Aggregation Process ◽  
Walk Dimension

Carbon nanotubes aggregation process in aggregates (bundles) has been studied. This process results in essential reduction of nanocomposites attainable elasticity modulus. The bundles packing density is defined by aggregation expectation time and corresponding carbon nanotube walk dimension up to sticking with a similar nanotube.

Modeling the interphase region in carbon nanotube‐reinforced polymer nanocomposites

2018 ◽  
Vol 40 (S2) ◽  
pp. E1219-E1234 ◽  
Author(s):  
Jafar Amraei ◽  
Jafar E. Jam ◽  
Behrouz Arab ◽  
Roohollah D. Firouz‐Abadi
Keyword(s):  
Carbon Nanotube ◽  
Polymer Nanocomposites ◽  
Interphase Region ◽  
Reinforced Polymer
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