scholarly journals On the effect of stiffness/softness and morphology of interphase phase on the effective elastic properties of three-phase composite material

2020 ◽  
Vol 15 (55) ◽  
pp. 36-49
Author(s):  
Fedaoui Kamel ◽  
Lazhar Baroura ◽  
Karim Arar ◽  
Hichem Amrani ◽  
Mohamed said Boutaani
Keyword(s):  
Composite Material ◽  
Elastic Properties ◽  
Volume Fraction ◽  
Mean Field ◽  
Young Modulus ◽  
Element Model ◽  
Three Phase ◽  
The Matrix ◽  
Mesh Density ◽  
Von Mises

In the present study, Composite material consisting of an elastic homogeneous isotropic matrix in which are embedded coated elastic isotropic inclusions, widely used in many applications is investigate by homogenization approach coupled to the finite elements method. A finite element model is proposed to predict the Young and Shear modulus of the three-phase composite containing spherical inclusions surrounded by a spherical or ellipsoid interphase layer. Three cases of particles volume fractions and interphase was considered with addition of two interphase morphology. Young modulus of interphase region was varied from soft to hard than the matrix properties. We note that interphase morphology and properties plays an important role in the elastic properties of composite with increasing the volume fraction of inclusions and interphase. The results were compared to the first order bounds Voigt and Reuss, and the mean field homogenization techniques. A sensitive study of the effect of mesh density on the results of the von Mises stresses and elastic properties has been made.

Micromechanical analysis of effective mechanical properties of graphene/ZrO2-hybrid poly (methyl methacrylate) nanocomposites

2021 ◽  
pp. 251659842110388
Author(s):  
Ankit Rathi ◽  
S. I. Kundalwal
Keyword(s):  
Methyl Methacrylate ◽  
Elastic Properties ◽  
Mechanical Performance ◽  
Volume Fraction ◽  
Element Model ◽  
Two Phase ◽  
Effective Elastic Properties ◽  
Poly Methyl Methacrylate ◽  
Three Phase ◽  
Effective Mechanical Properties

In this study, the tensile properties of two-phase and three-phase graphene/ZrO2-hybrid poly (methyl methacrylate) (PMMA) nanocomposites are investigated by developing finite element model using ANSYS. Primarily, the effective elastic properties of two- and three-phase graphene/ZrO2-hybrid PMMA nanocomposites (GRPCs) are estimated by developing mechanics of material (MOM) model. Results indicated that the effective elastic properties of GRPCs increase with an increase in the volume fraction of graphene. Also, the stiffness of GRPCs is increased by 78.12% with increasing in the volume fraction of graphene from 0.1 to 0.5 Vf. The incorporation of an additional ZrO2 interphase significantly improved the mechanical performance of resulting GRPCs.

Evaluation of Longitudinal and Transversal Young’s Moduli for Unidirectional Composite Material with Long Fibers

2011 ◽  
Vol 324 ◽  
pp. 189-192 ◽  
Author(s):  
Ali Hallal ◽  
Farouk Fardoun ◽  
Rafic Younes ◽  
Fadi Hage Chehade
Keyword(s):  
Composite Material ◽  
Elastic Properties ◽  
Isotropic Material ◽  
Volume Fraction ◽  
Micromechanical Model ◽  
Matrix Phase ◽  
Young’S Moduli ◽  
Analytical Results ◽  
The Matrix ◽  
Long Fibers

This work represents a comparative study of available analytical micromechanical models used to evaluate the elastic properties of unidirectional (UD) composite material with long fibers (where the ratio Length/Diameter of the fibers is considered to be infinite). The objective of this work is to find the appropriate model, to be used with different volume fractions of fibers, to determine the micromechanical elastic properties. This study is carried out due to the importance of using the suitable micromechanical model, when modeling bi-dimensional and tridimensional composite materials. The models are divided into two different categories: rheological, and inclusion models. The UD composite material represents a transversely isotropic material composed of two phases: the reinforcement phase and the matrix phase. Isotropic fibers (e.g. glass fibers) or anisotropic fibers (e.g. carbon fibers) represent the reinforcement phase while an isotropic material (e.g. epoxy) represents the matrix phase. In this study only longitudinal and transversal Young’s moduli are discussed. Analytical and Finite element modeling is made for a carbon fiber/epoxy UD composite. The obtained analytical results are compared to those obtained numerically and to the available experimental data. The analytical results are evaluated for different values of fiber volume fraction Vf ranging from 0 to 1.

Theoretical analysis of a rolling-sliding elastohydrodynamic lubrication line contact with a subsurface inclusion

2019 ◽  
Vol 233 (8) ◽  
pp. 1197-1207
Author(s):  
Armando Félix Quiñonez ◽  
Guillermo E Morales Espejel
Keyword(s):  
Elastohydrodynamic Lubrication ◽  
Element Model ◽  
Von Mises Stress ◽  
Transient Effects ◽  
Mean Velocity ◽  
The Matrix ◽  
Soft Inclusion ◽  
The Mean ◽  
Von Mises ◽  
Fully Coupled

This work investigates the transient effects of a single subsurface inclusion over the pressure, film thickness, and von Mises stress in a line elastohydrodynamic lubrication contact. Results are obtained with a fully-coupled finite element model for either a stiff or a soft inclusion moving at the speed of the surface. Two cases analyzed consider the inclusion moving either at the same speed as the mean velocity of the lubricant or moving slower. Two additional cases investigate reducing either the size of the inclusion or its stiffness differential with respect to the matrix. It is shown that the well-known two-wave elastohydrodynamic lubrication mechanism induced by surface features is also applicable to the inclusions. Also, that the effects of the inclusion become weaker both when its size is reduced and when its stiffness approaches that of the matrix. A direct comparison with predictions by the semi-analytical model of Morales-Espejel et al. ( Proc IMechE, Part J: J Engineering Tribology 2017; 231) shows reasonable qualitative agreement. Quantitatively some differences are observed which, after accounting for the semi-analytical model's simplicity, physical agreement, and computational efficiency, may then be considered as reasonable for engineering applications.

scholarly journals Effect of the matrix subsystem on hydrostatic parameters of a novel 1–3-type piezo-composite

2015 ◽  
Vol 08 (05) ◽  
pp. 1550049 ◽  
Author(s):  
Vitaly Yu. Topolov ◽  
Christopher R. Bowen ◽  
Paolo Bisegna ◽  
Anatoly E. Panich
Keyword(s):  
Elastic Properties ◽  
Electromechanical Coupling ◽  
Volume Fraction ◽  
Electromechanical Coupling Factor ◽  
Ferroelectric Ceramic ◽  
Coupling Factor ◽  
Polyurethane Composite ◽  
The Matrix ◽  
Type Composite

The influence of the aspect ratio and volume fraction of ferroelectric ceramic inclusions in a 0–3 matrix on the hydrostatic parameters of a three-component 1–3-type composite is studied to demonstrate the important role of the elastic properties of the two-component matrix on the composite performance. Differences in the elastic properties of the 0–3 matrix and single-crystal rods lead to a considerable dependence of the hydrostatic response of the composite on the anisotropy of the matrix elastic properties. The performance of a 1–0–3 0.92 Pb ( Zn 1/3 Nb 2/3) O 3–0.08 PbTiO 3 SC/modified PbTiO 3 ceramic/polyurethane composite suggests that this composite system is of interest for hydroacoustic applications due to its high hydrostatic piezoelectric coefficients [Formula: see text] and [Formula: see text], squared figure of merit [Formula: see text], and electromechanical coupling factor [Formula: see text].

The Estimation of Thermal Conductivity for Alumina-Epoxy Composite Material with High Filling Volume Fraction

2014 ◽  
Vol 918 ◽  
pp. 21-26
Author(s):  
Chen Kang Huang ◽  
Yun Ching Leong
Keyword(s):  
Thermal Conductivity ◽  
Composite Material ◽  
Composite Materials ◽  
Physical Model ◽  
Electron Scattering ◽  
Volume Fraction ◽  
Epoxy Composite ◽  
The Matrix ◽  
Transport Theorem ◽  
Good Agreement

In this study, the transport theorem of phonons and electrons is utilized to create a model to predict the thermal conductivity of composite materials. By observing or assuming the dopant displacement in the matrix, a physical model between dopant and matrix can be built, and the composite material can be divided into several regions. In each region, the phonon or electron scattering caused by boundaries, impurities, or U-processes was taken into account to calculate the thermal conductivity. The model is then used to predict the composite thermal conductivity for several composite materials. It shows a pretty good agreement with previous studies in literatures. Based on the model, some discussions about dopant size and volume fraction are also made.

Micromechanics Approach for the Overall Elastic Properties of Ceramic Matrix Composites Incorporating Defect Structures

2020 ◽  
Author(s):  
Rajesh S. Kumar
Keyword(s):  
Elastic Properties ◽  
Volume Fraction ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Volume Shrinkage ◽  
Matrix Composites ◽  
Defect Structures ◽  
Linear Elastic ◽  
Elastic Tensor ◽  
The Matrix

Abstract Initial mechanical behavior of Ceramic Matrix Composites (CMCs) is linear until the proportional limit. This initial behavior is characterized by linear elastic properties, which are anisotropic due to the orientation and arrangement of fibers in the matrix. The linear elastic properties are needed during various phases of analysis and design of CMC components. CMCs are typically made with ceramic unidirectional or woven fiber preforms embedded in a ceramic matrix formed via various processing routes. The matrix processing of interest in this work is that formed via Polymer Impregnation and Pyrolysis (PIP). As this process involves pyrolysis process to convert a pre-ceramic polymer into ceramic, considerable volume shrinkage occurs in the material. This volume shrinkage leads to significant defects in the final material in the forms of porosity of various size, shape, and volume fraction. These defect structures can have a significant impact on the elastic and damage response of the material. In this paper, we develop a new micromechanics modeling framework to study the effects of processing-induced defects on linear elastic response of a PIP-derived CMC. A combination of analytical and computational micromechanics approaches is used to derive the overall elastic tensor of the CMC as a function of the underlying constituents and/or defect structures. It is shown that the volume fraction and aspect ratio of porosity at various length-scales plays an important role in accurate prediction of the elastic tensor. Specifically, it is shown that the through-thickness elastic tensor components cannot be predicted accurately using the micromechanics models unless the effects of defects are considered.

Characristics of Shape Memory Composites Combined with Shape Memory Alloy and Shape Memory Polymer

2013 ◽  
Vol 705 ◽  
pp. 169-172
Author(s):  
Xue Feng ◽  
Li Min Zhao ◽  
Xu Jun Mi
Keyword(s):  
Shape Memory ◽  
Room Temperature ◽  
Shape Recovery ◽  
Volume Fraction ◽  
Shape Memory Polymer ◽  
Young Modulus ◽  
Thermomechanical Properties ◽  
The Matrix ◽  
Shape Memory Composites ◽  
Shape Fixity

In order to develop high functionality of shape memory materials, the shape memory composites combined with TiNi wire and shape memory epoxy were prepared, and the mechanical and thermomechanical properties were studied. The results showed the addition of TiNi wire increased the Young modulus and breaking strength both at room temperature and at elevated temperature. The composites maintained the rates of shape fixity and shape recovery close to 100%. The maximum recovery stress increased with increasing TiNi wire volume fraction, and obtained almost 3 times of the matrix by adding 1vol% TiNi wire.

Micromechanics Approach for the Overall Elastic Properties of Ceramic Matrix Composites Incorporating Defect Structures

2021 ◽  
Author(s):  
Rajesh Kumar
Keyword(s):  
Elastic Properties ◽  
Volume Fraction ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Matrix Composites ◽  
Defect Structures ◽  
Modeling Framework ◽  
Linear Elastic ◽  
Elastic Tensor ◽  
The Matrix

Abstract Initial mechanical behavior of Ceramic Matrix Composites (CMCs) is linear until the proportional limit. This initial behavior is characterized by linear elastic properties, which are anisotropic due to the orientation and arrangement of fibers in the matrix. The linear elastic properties are needed during analysis and design of CMC components. CMCs are made with ceramic unidirectional or woven fiber preforms embedded in a ceramic matrix formed via various processing routes. The matrix processing of interest in this work is the Polymer Impregnation and Pyrolysis (PIP) process. As this process involves pyrolysis to convert a pre-ceramic polymer into ceramic, considerable volume shrinkage occurs in the material. This leads to significant defects in the form of porosity of various size, shape, and volume fraction. These defect structures can have a significant impact on the elastic and damage response of the material. In this paper, we develop a new micromechanics modeling framework to study the effects of processing-induced defects on linear elastic response of a PIP-derived CMC. A combination of analytical and computational micromechanics approaches is used to derive the overall elastic tensor of the CMC as a function of the underlying constituents and/or defect structures. It is shown that the volume fraction and aspect ratio of porosity at various length-scales plays an important role in accurate prediction of the elastic tensor. Specifically, it is shown that the through-thickness elastic tensor components cannot be predicted accurately using the micromechanics models unless the effects of defects are considered.

scholarly journals Finite Element Simulation of the Thermo-mechanical Response of Graphene Reinforced Nanocomposites

2018 ◽  
Vol 188 ◽  
pp. 01016
Author(s):  
Androniki S. Tsiamaki ◽  
Nick K. Anifantis
Keyword(s):  
Finite Element ◽  
Mechanical Behavior ◽  
Mechanical Response ◽  
Volume Fraction ◽  
Matrix Material ◽  
Continuum Theory ◽  
Element Model ◽  
Multilayer Graphene ◽  
Temperature Changes ◽  
The Matrix

The research for new materials that can withstand extreme temperatures and present good mechanical behavior is of great importance. The interest is highly focused on the utilization of composites reinforced by nanomaterials. To cope with this goal the present work studies the mechanical response of graphene reinforced nanocomposite structures subjected to temperature changes. A computational finite element model has been developed that accounts for both the reinforcement and the matrix material phases. The model developed is based on both the continuum theory and the molecular mechanics theory, for the simulation of the three different material phases of the composite, respectively, i.e. the matrix, the intermediate transition phase and the reinforcement. Considering this model, the mechanical response of an appropriate representative volume element of the nanocomposite is simulated under various temperature changes. The study involves different types of reinforcement composed from either monolayer or multilayer graphene sheets. Apart from the investigation of the behavior of a nanocomposite with each particular type of the reinforcement, comparisons are also presented between them in order to reveal optimized material combinations. The principal parameters taken into consideration, which contribute also to the mechanical behavior of the nanocomposite, are its size, the sheet multiplicity as well as the volume fraction.

A Study on the Thermoelastic Analysis in Shear Deformable Discontinuous Composites

2004 ◽  
Vol 261-263 ◽  
pp. 645-650
Author(s):  
Hong Gun Kim
Keyword(s):  
Thermal Stresses ◽  
Volume Fraction ◽  
Coefficient Of Thermal Expansion ◽  
Fiber Composite ◽  
Element Model ◽  
Short Fiber ◽  
Elastic Stresses ◽  
Fiber Aspect Ratio ◽  
The Matrix ◽  
Lag Model

A stress analysis has been performed to evaluate the thermally induced elastic stresses which can develop in a short fiber composite due to coefficient of thermal expansion (CTE) mismatch. An axisymmetric finite element model with the constraint between cells has implemented to find the magnitude of thermoelastic stresses in the fiber and the matrix as a function of volume fraction, CTE ratio, modulus ratio, and fiber aspect ratio. It was found that the matrix end regions fall under significant thermal stresses that have the same sign as that of the fibers themselves. Furthermore, it was found that the stresses vary along the fiber and fiber end gap in the same manner as that obtained in a shear-lag model during non-thermal mechanical loading.

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