Modeling and Analysis the Effect of Helical Carbon Nanotube Morphology on the Mechanical Properties of Nanocomposites Using Hexagonal Representative Volume Element

2014 ◽  
Vol 577 ◽  
pp. 3-6
Author(s):  
Minh Tai Le ◽  
Shyh Chour Huang
Keyword(s):  
Mechanical Properties ◽  
Finite Element Method ◽  
Representative Volume Element ◽  
Theory Of Elasticity ◽  
Volume Element ◽  
Modeling And Analysis ◽  
New Class ◽  
Representative Volume ◽  
The Matrix ◽  
Effective Mechanical Properties

Carbon nanotubes (CNTs) are the ultimate reinforcing materials for the development of an entirely new class of composites. However, they have the complicated shapes and do not usually appear as straight reinforcements when introduced in polymer matrices. This decreases nanotube’s effectiveness in enhancing the matrix mechanical properties. In this paper, nanostructure having hexagonal representative volume element (RVE), theory of elasticity of anisotropic materials and finite element method (FEM) are used to investigate the effect of helical CNT morphology on effective mechanical properties of nanocomposites. CNT with different helical angles are modeled to estimate the nanocomposite mechanical properties. The results of helical nanotube models are compared with the effective mechanical properties of nanocomposites reinforced with straight nanotubes.

scholarly journals EFFECT OF INTERPHASE CHARACTERISTIC AND PROPERTY ON AXIAL MODULUS OF CARBON NANOTUBE BASED COMPOSITES

1970 ◽  
Vol 41 (1) ◽  
pp. 15-24 ◽  
Author(s):  
Md. Abdulla Al Masud ◽  
A. K. M. Masud
Keyword(s):  
Mechanical Properties ◽  
Finite Element Method ◽  
Finite Element ◽  
Carbon Nanotube ◽  
Representative Volume Element ◽  
Volume Element ◽  
Representative Volume ◽  
Tensile Elastic Modulus ◽  
Micrometer Size ◽  
Element Method

In carbon nanotube (CNT) based composite, due to the small (micrometer) size of reinforcements a large amount of interphases is developed during the time of production. It is important to assess whether the interphase is responsible for the poor mechanical properties of CNT-reinforced composite. In this research, the effect of interphase property and characteristics on effective mechanical properties of CNT based composites is evaluated using a 3-D nanoscale representative volume element (RVE). The effect of both soft and stiff interphases on the Tensile Elastic Modulus (TEM) of nanocomposites is investigated using the Finite Element Method (FEM) for the case of both long and short CNTs. With the increase of thickness of stiff interphase, the stiffness of the composite increases significantly for both the short and long CNT cases. On the other hand the increase of thickness of soft interphase reduces the stiffness of the overall composite in a considerable amount.Key Words: Carbon nanotube; Interphase; Representative Volume Element; Finite Element method; TensileElastic Modulus.DOI: 10.3329/jme.v41i1.5358Journal of Mechanical Engineering, Vol. ME 41, No. 1, June 2010 15-24 

scholarly journals A Study on the Mechanical Properties of the Representative Volume Element in Fractal Porous Media

Geofluids ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Jianjun Liu ◽  
Mingyang Wu ◽  
Zhengwen Zhu ◽  
Zuliang Shao
Keyword(s):  
Mechanical Properties ◽  
Porous Media ◽  
Fractal Dimension ◽  
Representative Volume Element ◽  
Mechanical Response ◽  
Volume Element ◽  
Structure Generation ◽  
Matrix Mechanics ◽  
Representative Volume ◽  
The Matrix

Natural porous structure is extremely complex, and it is of great significance to study the macroscopic mechanical response of the representative volume element (RVE) with the microstructure of porous media. The real porous media RVE is generated by an improved quartet structure generation set (QSGS), and the connectivity of the reconstructed porous media models is analyzed. The fractal dimension of the RVE is calculated by the box-counting method, which considers the different porosity, different fractal dimension, and different mechanical properties of the matrix. Thus, the stress-strain curves of the RVE in the elastoplastic stage under different conditions are obtained. The results show that when the matrix mechanics are consistent, the mechanical properties of the porous media RVE are negatively correlated with the porosity and fractal dimension; when the difference between the porosity and fractal dimension increases, the trend is more obvious. The mechanical properties of the RVE have a positive correlation with the modulus of elasticity of the matrix, though the correlation with Poisson’s ratio of the matrix is weak. The fractal dimension of complex porous media can better predict the RVE mechanical characteristics than the porosity.

Representative Volume Element for Mechanical Properties of Carbon Nanotube Nanocomposites Using Stochastic Finite Element Analysis

2020 ◽  
Vol 142 (3) ◽  
Author(s):  
Seyed Hamid Reza Sanei ◽  
Randall Doles
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Representative Volume Element ◽  
Volume Element ◽  
Length Scale ◽  
Stochastic Finite Element ◽  
Element Analysis ◽  
Representative Volume ◽  
Element Approach ◽  
Stochastic Finite Element Analysis

Abstract The aim of this study is to present a representative volume element (RVE) for nanocomposites with different microstructural features using a stochastic finite element approach. To that end, computer-simulated microstructures of nanocomposites were generated to include a variety of uncertainty present in geometry, orientation, and distribution of carbon nanotubes. Microstructures were converted into finite element models based on an image-based approach for the determination of elastic properties. For each microstructure type, 50 realizations of synthetic microstructures were generated to capture the variability as well as the average values. Computer-simulated microstructures were generated at different length scales to determine the change in mechanical properties as a function of length scale. A representative volume element is defined at a length scale beyond which no change in variability is observed. The results show that there is no universal RVE applicable to all properties and microstructures; however, the RVE size is highly dependent on microstructural features. Microstructures with agglomeration tend to require larger RVE. Similarly, random microstructures require larger RVE when compared with aligned microstructures.

Three-phase micromechanical analysis of residual stresses in reinforced fiber by carbon nanotubes

2016 ◽  
Vol 51 (12) ◽  
pp. 1783-1794 ◽  
Author(s):  
Ahmad Reza Ghasemi ◽  
Mohammad Mohammadi Fesharaki ◽  
Masood Mohandes
Keyword(s):  
Finite Element Method ◽  
Carbon Nanotubes ◽  
Finite Element ◽  
Carbon Fiber ◽  
Residual Stresses ◽  
Representative Volume Element ◽  
Volume Element ◽  
The Finite Element Method ◽  
Representative Volume ◽  
Element Method

In this study, circular disk model and cylinder theory for two dimension (2D) and three dimension (3D), respectively, have been used to determine residual stresses in three-phase representative volume element. The representative volume element is consisting of three phases: carbon fiber, carbon nanotubes, and polymer matrix, that carbon fiber is reinforced by carbon nanotube using electrophoresis method. Initially, the residual stresses analysis of two-phase representative volume element has been implemented. The two-phase representative volume element has been divided to carbon fiber and matrix phases with different volume fractions. In the three-phase representative volume element, although the volume fraction of carbon fiber is constant and equal to 60%, the volume fractions of carbon nanotubes for various cases are different as 0%, 1%, 2%, 3%, 4%, and 5%. Also, there are two different methods to reinforce the fiber according to different coefficients of thermal expansion of the carbon fiber and carbon nanotube in two longitudinal and transverse directions; carbon nanotubes are placed on carbon fiber either parallel or around it like a ring. Subsequently, finite element method and circular disk model have been used for analyzing micromechanic of the residual stresses for 2D and then the results of stress invariant obtained by the finite element method have been compared with the circular disk model. Moreover, for 3D model, the finite element method and cylinder theory have been utilized for micromechanical analysis of the residual stresses and the results of stress invariant obtained by them, have been compared with each other. Results of the finite element method and analytical model have good agreement in 2D and 3D models.

Prediction of Rice Husk Particulate-Filled Polymer Composite Properties Using a Representative Volume Element (RVE) Model

2015 ◽  
Author(s):  
Pandhita Pochanard ◽  
Anil Saigal
Keyword(s):  
Mechanical Properties ◽  
Representative Volume Element ◽  
Rice Husk ◽  
Agricultural Waste ◽  
Volume Element ◽  
Raw Material ◽  
Analytical Models ◽  
Volume Percentage ◽  
Waste Products ◽  
Representative Volume

In this study, a numerical representative volume element (RVE) model was used to predict the mechanical properties of a Rice Husk Particulate (RHP)-Epoxy composite for use as an alternative material in non-critical applications. Seven different analytical models Counto, Ishai-Cohen, Halpin-Tsai, Nielsen, Nicolais, Modified Nicolais and Pukanszky were used as comparison tools for the numerical model. The mechanical properties estimated for 0%, 10% and 30% RHP-Epoxy composites using the numerical and analytical models are in general agreement with each other. Using the analytical models, it was calculated that an increase in volume percentage of RHP to 30% led to continual reduction in elastic Young’s modulus and ultimate tensile strength of the composite. The numerical RVE models also predicted a similar trend between filler volume percentage and material properties. Overall, the results of this study suggest that RHP can be used to reduce the composite raw material costs by replacing the more expensive polymer content with agricultural waste products with limited compromise to the composite’s mechanical properties.

scholarly journals Influence of Boundary Conditions on Numerical Homogenization of High Performance Concrete

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1009
Author(s):  
Arkadiusz Denisiewicz ◽  
Mieczysław Kuczma ◽  
Krzysztof Kula ◽  
Tomasz Socha
Keyword(s):  
Experimental Data ◽  
Finite Element Method ◽  
Finite Element ◽  
Boundary Conditions ◽  
Representative Volume Element ◽  
High Performance ◽  
High Performance Concrete ◽  
Volume Element ◽  
Numerical Homogenization ◽  
Representative Volume

Concrete is the most widely used construction material nowadays. We are concerned with the computational modelling and laboratory testing of high-performance concrete (HPC). The idea of HPC is to enhance the functionality and sustainability of normal concrete, especially by its greater ductility as well as higher compressive, tensile, and flexural strengths. In this paper, the influence of three types (linear displacement, uniform traction, and periodic) of boundary conditions used in numerical homogenization on the calculated values of HPC properties is determined and compared with experimental data. We take into account the softening behavior of HPC due to the development of damage (micro-cracks), which finally leads to failure. The results of numerical simulations of the HPC samples were obtained by using the Abaqus package that we supplemented with our in-house finite element method (FEM) computer programs written in Python and the homogenization toolbox Homtools. This has allowed us to better account for the nonlinear response of concrete. In studying the microstructure of HPC, we considered a two-dimensional representative volume element using the finite element method. Because of the random character of the arrangement of concrete’s components, we utilized a stochastic method to generate the representative volume element (RVE) structure. Different constitutive models were used for the components of HPC: quartz sand—linear elastic, steel fibers—ideal elastic-plastic, and cement matrix—concrete damage plasticity. The numerical results obtained are compared with our own experimental data and those from the literature, and a good agreement can be observed.

scholarly journals Study on Macroscopic and Microscopic Mechanical Behavior of Magnetorheological Elastomers by Representative Volume Element Approach

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Shulei Sun ◽  
Xiongqi Peng ◽  
Zaoyang Guo
Keyword(s):  
Magnetic Field ◽  
Mechanical Properties ◽  
Shear Modulus ◽  
Representative Volume Element ◽  
Field Intensity ◽  
Magnetic Field Intensity ◽  
Volume Fraction ◽  
Volume Element ◽  
Magnetorheological Elastomers ◽  
Representative Volume

By using a representative volume element (RVE) approach, this paper investigates the effective mechanical properties of anisotropic magnetorheological elastomers (MREs) in which particles are aligned and form chain-like structure under magnetic field during curing. Firstly, a three-dimensional RVE in zero magnetic field is presented in ABAQUS/Standard to calculate the macroscopic mechanical properties of MREs. It is shown that the initial shear modulus of MREs increases by 56% with a 20% volume fraction of particles compared to that of pure rubber. Then by introducing the Maxwell stress tensor, a two-dimensional plane stress RVE for the MRE is developed in COMSOL Multiphysics to study its response under a magnetic field. The influences of magnetic field intensity, radius of particles, and distance between two adjacent particles on the macroscopic mechanical properties of MRE are also investigated. The results show that the shear modulus increases with the increase of the applied magnetic field intensity and the radius of particles and the decrease of the distance between two adjacent particles in a chain. The predicted numerical results are consistent with theoretical results from Mori-Tanaka model, double inclusion model, and dipole model.

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