scholarly journals Representative volume element based micromechanical modelling of rod shaped glass filled epoxy composites

2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Aanchna Sharma ◽  
Yashwant Munde ◽  
Vinod Kushvaha

AbstractIn this study, Representative Volume Element based micromechanical modeling technique has been implemented to assess the mechanical properties of glass filled epoxy composites. Rod shaped glass fillers having an aspect ratio of 80 were used for preparing the epoxy composite. The three-dimensional unit cell model of representative volume element was prepared with finite element analysis tool ANSYS 19 using the periodic square and hexagonal array with an assumption that there is a perfect bonding between the filler and the epoxy matrix. Results revealed that the tensile modulus increases and Poisson’s ratio decreases with increase in the volume fraction of the filler. To study the effect of filler volume fraction, the pulse echo techniques were used to experimentally measure the tensile modulus and Poisson’s ratio for 5% to 15% volume fraction of the filler. A good agreement was found between the RVE based predicted values and the experimental results.

2016 ◽  
Vol 101 ◽  
pp. 27-39 ◽  
Author(s):  
Maedeh Amirmaleki ◽  
Javad Samei ◽  
Daniel E. Green ◽  
Isadora van Riemsdijk ◽  
Lorna Stewart

TAPPI Journal ◽  
2018 ◽  
Vol 17 (06) ◽  
pp. 329-339 ◽  
Author(s):  
Yujun Li ◽  
Zengzhi Yu ◽  
Stefanie Reese ◽  
Jaan-Willem Simon

Many natural and synthetic materials have fibrous microstructures, including nonwoven fabrics, paper, and fiberboard. Experimentally evaluating their out-of-plane mechanical behavior can be difficult because of the small thickness compared with the in-plane dimension. To properly predict such properties, network-scale models are required to obtain homogenized material mechanics by considering fiber-scale mechanisms. We demonstrate a three-dimensional representative volume element (RVE) for fiber networks using the finite element method. We first adopted the classical deposition procedure to generate fiber networks with random or preferential fiber orientations and then an artificial compression to achieve the practical fiber volume fraction. The hollow fibers, described with elastic-plastic brick elements, were joined by interface-based cohesive zone elements introduced in all fiber-fiber contact areas. Thereafter, the fiber networks were subjected to displacement boundary conditions, and their apparent mechanical response was evaluated by a homogenized stress. To determine the RVE dimension, we further conducted an RVE size convergence study for the out-of-plane compression and tension (varying specimen length while keeping the specimen thickness constant). Finally, we evaluated the apparent out-of-plane response of the obtained RVE for four loading cases: out-of-plane compression, tension, simple shear, and pure shear. The results show a quite different mechanical behavior of fiber networks between all these out-of-plane loading cases, particularly between tension and compression.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Shulei Sun ◽  
Xiongqi Peng ◽  
Zaoyang Guo

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.


2020 ◽  
Vol 10 (3) ◽  
pp. 5660-5664

Coating treatment is a new method to improve the overall properties of natural fibres. However, recent research paying less attention to the effects of coating solution viscosities towards the coating behaviour inside the fibres embedded in the composite system. Thus, this study explores the effects of coating domination to the deformation of the composite from the analysis of coating uptake, maximum tensile modulus and the Poisson’s ratio. The samples were prepared by dipping the fibres in 1:4, 1:5 and 1:6 coating solutions, cured and pulverised prior moulded and tensile tested. The result shows that 1:6 coated fibre is the best since it improves about 40.1 % of coating uptake, 23.8-31.4 % of maximum tensile modulus with highest Poisson’s ratio of composites properties. It also supported by its scanning electron micrograph as better fibre-matrix interaction was observed. The high coating penetration in the structure of the fibre might change the fibres natural polarity and improves the fibre-matrix interaction to reduce the deformation of the composite to give a stiff composites property. Conclusively, the optimum coating solution is needed since it influences the fibres coating behaviour to control the deformation of the composites.


2020 ◽  
Vol 5 (2) ◽  
pp. 17-29
Author(s):  
Ahmad Fuad Ab Ghani

The properties such as fibre content, orientation, dimension of constituent fibres (diameter), level of intermixing of fibres, interface bonding between fibre and matrix, and arrangement of fibres between different types of fibres, influences the mechanical properties of hybrid composite.Representative Volume Element (RVE) for each constituent CFRP and GFRP assumed isotropic behavior for carbon fibre, glass fibre and epoxy resin matrix and assumed to be perfectly bonded interface between fibre and matrix region i.e. strain compatibility at the interface. The scope of study on the micro mechanical modelling via representative volume element (RVE) is limited only to unidirectional composites.


Author(s):  
Bhavik A Ardeshana ◽  
Umang B Jani ◽  
Ajay M Patel ◽  
Anand Y Joshi

This paper deals with the evaluation of the effective mechanical properties of carbon nanocone centered composites using a 3D nanoscale representative volume element based on continuum mechanics. For extracting the effective material constants, the authors have taken the basis of theories of elasticity. The results constituting the effective Young's modulus of the composite and Poisson's ratio for different parameters stated above have been presented and validated with rule of mixtures. It can be clearly visualized from the results that the load-carrying capacities of carbon nanocones in the representative volume elements are quite significant and the same has been demonstrated with subsequent cases. Simulation-based modeling can show a considerable part in the improvement of carbon nanocone-based composites by providing results that help in appreciative of the performance of composites. Moreover, for a volume fraction of the CNC as 2.33% in a cylindrical representative volume element and a 19.2° apex angle of the cone, the stiffness of the composite can increase as many as 4.9 times of the matrix. Similarly for hexagonal and square, the increase is in terms of 4.3 and 3.01 times respectively. Cylindrical representative volume element is the best as it provides the maximum reinforcement in terms of effective Young's modulus of the composite. Carbon nanocone-based composites provide results that help in understanding the elastic behavior of composites.


2013 ◽  
Vol 275-277 ◽  
pp. 1605-1609
Author(s):  
Nan Zhang ◽  
Cheng Hong Duan

In this paper, a representative volume element (RVE) model of composites with different fiber volume fraction is established by ANSYS finite element software. The stiffness matrix of the RVE model can be calculated by studying its stress field, and then the elastic properties of composites could be obtained. By comparing with the results from NASA empirical equation, the reliability of the method can be proved. This is a new way to predict the elastic properties of composites.


Author(s):  
Jacob M. Wernik ◽  
Shaker A. Meguid

In this work, the mechanical properties of carbon nanotube reinforced structural adhesive bonds are investigated both theoretically and experimentally. The theoretical investigations employ a novel multiscale modeling technique that integrates governing atomistic constitutive laws in a continuum framework. This technique takes into account the discrete nature of the atomic interactions at the nanometer length scale and the interfacial characteristics of the nanotube and the surrounding polymer matrix. Appropriate formulations are developed to allow for the atomistic-based continuum modelling of nano-reinforced structural adhesive bonds on the basis of a nanoscale representative volume element that accounts for the nonlinear behaviour of its constituents; namely, the reinforcing carbon nanotube, the surrounding adhesive and their interface. This model is used to evaluate the constitutive response of carbon nanotubes with varied chiral indices. The newly developed representative volume element is then used with analytical micromechanical modeling techniques to investigate the homogeneous and dispersion of the reinforcing element into the adhesive considered upon the linear elastic properties.


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