Numerical Simulation of the Effect of Particle Random Spatial Distribution on the Thermal Conductivity of Composites

2013 ◽  
Vol 561 ◽  
pp. 130-134
Author(s):  
Xiao Guang Zhang ◽  
Ying Jie Ji ◽  
Shi Gang Wang ◽  
Xiao Li
Keyword(s):  
Thermal Conductivity ◽  
Spatial Distribution ◽  
Random Distribution ◽  
Volume Fraction ◽  
Volume Element ◽  
Reinforced Composites ◽  
Practical Applications ◽  
Particle Reinforced Composites ◽  
Simulation Results ◽  
Ansys Workbench

The overall thermal properties of particle reinforced composites are of primary importance for practical applications. Effect of random spatial distribution of sphere particles on the thermal conductivity of composites was numerically studied by ANSYS Workbench Steady-State Thermal analysis module. MATLAB procedure is used to achieve random distribution of particles in composites and to generate a representative volume element (RVE) model. The simulation results indicate that, at the same volume fraction, the random distribution has higher thermal conductivity than the uniform distribution; effect of particles’ spatial distribution on thermal conductivity is greater than volume fraction especially when the volume fraction is between 15% and 35%.

scholarly journals A novel determination of the minimal size of a probabilistic representative volume element for fiber-reinforced composites’ thermal analysis

2018 ◽  
Vol 22 (6 Part A) ◽  
pp. 2551-2564
Author(s):  
Zecan Tu ◽  
Junkui Mao ◽  
Junjun Mao ◽  
Hua Jiang
Keyword(s):  
Thermal Conductivity ◽  
Thermal Analysis ◽  
Heat Flux ◽  
Thermal Gradient ◽  
Volume Fraction ◽  
Volume Element ◽  
Fiber Reinforced Composites ◽  
Reinforced Composites ◽  
Minimal Size ◽  
Fiber Reinforced

In order to provide an accurate thermal analysis method of fiber-reinforced composites, a novel model based on a probabilistic representative volume element (RVE) is presented in this paper. Monte Carlo methods, probability analysis and finite element analysis have been applied together. The effective transverse thermal conductivity, heat flux field, and thermal gradient field of typical fiber-reinforced composites are examined. The criteria of RVE have been determined, and the minimal size for thermal analysis is obtained using the main statistics and the cross-entropy theory. At the same time, the fiber-to-matrix ratio of thermal conductivity and volume fraction have been changed to determine the influence on heat transfer inside fiber-reinforced composites. It is shown that different purposes of simulations lead to different minimal RVE sizes. The numerical results indicate that the non-dimensional minimal RVE sizes for calculating the effective thermal conductivity, heat flux, and thermal gradient are 30, 80, and 80, respectively. Compared with the volume fraction, the fiber-to-matrix ratio of the thermal conductivity has a more significant effect on minimal RVE size. When the thermal conductivity ratio increases, the minimal size of the RVE increases at first, then it remains almost unchanged.

Numerical Simulation on Mechanical Properties of SiC/Al Co-Continuous Composites

2011 ◽  
Vol 213 ◽  
pp. 186-190 ◽  
Author(s):  
Ming Juan Zhao ◽  
Na Li ◽  
Long Zhi Zhao ◽  
Xiao Lan Zhang
Keyword(s):  
Mechanical Properties ◽  
Numerical Simulation ◽  
Stress Concentration ◽  
Yield Strength ◽  
Volume Fraction ◽  
Reinforced Composites ◽  
Ansys Software ◽  
Kelvin Model ◽  
Particle Reinforced Composites ◽  
Simulation Results

Mechanical properties of the co-continuous SiC/Al composites were simulated using the ANSYS software in this paper, and Kelvin model was adopted as SiC structure. The models of various SiC contents were calculated for composites, the influences of SiC volume fraction on the interface were analyzed. Compared with the particle reinforced composites, the influences of SiC structure on the interface and strength were investigated. The results showed that the SiC volume fraction has a certain effect on the interface of composites, the incoordination of deformation of SiC and Al causes the greater stress concentration with SiC volume fraction decreases, so that interface occurs the debonding. Compared the simulation results of co-continuous composites and particle reinforced composites, two stress-distance curves show that the stress decreases with the distance from the interface increases, and two stress-strain curves prove that the co-continuous composites have higher the yield strength and the deforming resistance.

scholarly journals Isotope Effect on the Thermal Conductivity of Graphene

2010 ◽  
Vol 2010 ◽  
pp. 1-5 ◽  
Author(s):  
Hengji Zhang ◽  
Geunsik Lee ◽  
Alexandre F. Fonseca ◽  
Tammie L. Borders ◽  
Kyeongjae Cho
Keyword(s):  
Thermal Conductivity ◽  
Molecular Dynamics ◽  
Electronic Structure ◽  
Isotope Effect ◽  
Random Distribution ◽  
Molecular Dynamics Method ◽  
Promising Application ◽  
Simulation Results ◽  
Atomic And Electronic Structure ◽  
Dynamics Method

The thermal conductivity (TC) of isolated graphene with different concentrations of isotope (C13) is studied with equilibrium molecular dynamics method at 300 K. In the limit of pure C12or C13graphene, TC of graphene in zigzag and armchair directions are ~630 W/mK and ~1000W/mK, respectively. We find that the TC of graphene can be maximally reduced by ~80%, in both armchair and zigzag directions, when a random distribution of C12and C13is assumed at different doping concentrations. Therefore, our simulation results suggest an effective way to tune the TC of graphene without changing its atomic and electronic structure, thus yielding a promising application for nanoelectronics and thermoelectricity of graphene-based nano device.

An Interfacial Debonding Model for Particle-Reinforced Composites

2002 ◽  
Author(s):  
H. T. Liu ◽  
L. Z. Sun ◽  
J. W. Ju
Keyword(s):  
Volume Fraction ◽  
Three Dimensional ◽  
Damage Mechanism ◽  
Interfacial Debonding ◽  
Elastic Behavior ◽  
Reinforced Composites ◽  
Stiffness Tensor ◽  
Particle Reinforced Composites ◽  
Damage Process ◽  
Multi Phase

To simulate the evolution process of interfacial debonding between particle and matrix, and to further estimate its effect on the overall elastic behavior of particle-reinforced composites, a two-level microstructural-effective damaged model is developed. The microstructural damage mechanism is governed by the interfacial debonding of reinforcement and matrix. The progressive damage process is represented by the debonding angles that are dependent on the external loads. For those debonded particles, the elastic equivalency is constructed in terms of the stiffness tensor. Namely, the isotropic yet debonded particles are replaced by the orthotropic perfect particles. The volume fraction evolution of debonded particles is characterized by the Weibull’s statistical approach. Mori-Tanaka’s method is utilized to determine the effective stiffness tensor of the resultant multi-phase composites. The proposed constitutive framework is developed under the general three-dimensional loading condition. Examples are conducted to demonstrate the capability of the proposed model.

The spatial distribution of spheres falling in a viscous liquid

1968 ◽  
Vol 32 (1) ◽  
pp. 203-207 ◽  
Author(s):  
T. N. Smith
Keyword(s):  
Reynolds Number ◽  
Spatial Distribution ◽  
Viscous Liquid ◽  
Random Distribution ◽  
Volume Fraction ◽  
Solid Volume Fraction ◽  
Binomial Probability ◽  
Single Sphere

The spatial distribution of uniformly sized spheres falling in a viscous liquid is investigated experimentally for a solid volume fraction of 0·025 and a single sphere Reynolds number of 0·6. The observed spatial distribution agrees closely with a random distribution based on allocation of spheres to space cells according to a binomial probability mechanism.

Numerical Analysis of the Transverse Thermal Conductivity of Composites With Imperfect Interfaces

2003 ◽  
Vol 125 (3) ◽  
pp. 389-393 ◽  
Author(s):  
Samuel Graham ◽  
David L. McDowell
Keyword(s):  
Thermal Conductivity ◽  
Volume Fraction ◽  
Ceramic Composites ◽  
Reinforced Composites ◽  
Continuous Fiber ◽  
Fiber Volume ◽  
Element Analysis ◽  
Imperfect Interfaces ◽  
Transverse Thermal Conductivity ◽  
Johnson Model

Estimation of the transverse thermal conductivity of continuous fiber reinforced composites containing a random fiber distribution with imperfect interfaces was performed using finite element analysis. FEA results were compared with the classical solution of Hasselman and Johnson to determine limits of applicability. The results show that the Hasselman and Johnson model predicts the effective thermal conductivity within 3 percent of the numerical estimates for interfacial conductance values of 1×10−2−1×103W/m2K, fiber-matrix conductivity ratios between 1 and 100, and fiber volume fractions up to 50 percent which are properties typical of ceramic composites. The results show that the applicability of the classical dilute concentration model can not be determined by constituent volume fraction, but by the degree of interaction between the microstructural heterogeneities.

Microstructure Modeling for Prediction of Thermal Conductivity of Plain Weave C/SiC Composites Considering Manufacturing Flaws

2012 ◽  
Vol 460 ◽  
pp. 342-346 ◽  
Author(s):  
Sheng Shan Li ◽  
Xiao Yan Tong ◽  
Lei Jiang Yao ◽  
Bin Li
Keyword(s):  
Thermal Conductivity ◽  
Volume Fraction ◽  
Volume Element ◽  
Thickness Direction ◽  
Analysis Method ◽  
Plain Weave ◽  
Microstructure Modeling ◽  
Matrix Cracks ◽  
Plane Direction ◽  
Sic Composites

Utilized photomicrographs taken by scanning electron microscope (SEM), an accurate representative volume element (RVE) model for plain weave C/SiC composites is established. Based on the steady-analysis method, the in-plane and thickness direction thermal conductivity of the C/SiC composites are calculated as 25.6Wm-1K-1 and 12.1Wm-1K-1, respectively. The manufacturing flaws have different effect on thermal conductivity. Compared with RVE without flaws, the result shows that matrix cracks make thermal conductivity decrease by 7.2% in the in-plane direction and have little effect in the thickness direction; matrix porosities have a significant effect on thermal conductivity, which make the thermal conductivity decrease by 16.7% in the in-plane direction and decrease by 25.4% in the thickness direction. The variation law of thermal conductivity along with porosity volume is also observed: as matrix porosity volume fraction is increasing, the thermal conductivity of material shows significant decrease.

Geometrical Anisotropy in Biphase Particle Reinforced Composites

2010 ◽  
Vol 77 (4) ◽  
Author(s):  
Shivakumar I. Ranganathan ◽  
Paolo Decuzzi ◽  
Lewis T. Wheeler ◽  
Mauro Ferrari
Keyword(s):  
Composite Materials ◽  
Elastic Constants ◽  
Crucial Role ◽  
Particle Shape ◽  
Volume Fraction ◽  
Effective Stiffness ◽  
Reinforced Composites ◽  
Effective Elastic Constants ◽  
Anisotropy Index ◽  
Particle Reinforced Composites

Particle shape plays a crucial role in the design of novel reinforced composites. We introduce the notion of a geometrical anisotropy index A to characterize the particle shape and establish its relationship with the effective elastic constants of biphase composite materials. Our analysis identifies three distinct regions of A: (i) By using ovoidal particles with small A, the effective stiffness scales linearly with A for a given volume fraction α; (ii) for intermediate values of A, the use of prolate particles yield better elastic properties; and (iii) for large A, the use of oblate particles result in higher effective stiffness. Interestingly, the transition from (ii) to (iii) occurs at a critical anisotropy Acr and is independent of α.

Tensile Properties of Random Distribution Short SMA Fiber Reinforced Composites

2011 ◽  
Vol 488-489 ◽  
pp. 686-689
Author(s):  
Hong Shuai Lei ◽  
Bo Zhou ◽  
Zhen Qing Wang ◽  
Xiao Qiang Wang
Keyword(s):  
Random Distribution ◽  
Volume Fraction ◽  
Effective Elastic Modulus ◽  
Fiber Reinforced Composites ◽  
Reinforced Composites ◽  
Fiber Reinforced ◽  
Fiber Volume ◽  
Equivalent Inclusion Method ◽  
Equivalent Inclusion ◽  
Three Phase

Shape memory alloy (SMA) reinforced composites have been widely used in aerospace engineering fields. In this paper, four basic assumptions were presented to simply the research model based on the Eshelby’s equivalent inclusion method and Mori-Tanaka scheme. Based on the three-phase equivalent system and two-step equivalent process, the effective elastic modulus and thermal expansion coefficient of unidirectional random distribution short SMA fiber reinforced composites were derived. The tensile mechanical properties of composites with fiber volume fraction (15%), size (L=3, D=1; L=5, D=1), and number (N= 30, 50), were simulated using software ANSYS12.0, and discussed the failure mode of the composites.

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