scholarly journals A Lattice Model for Elastic Particulate Composites

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1584 ◽  
Author(s):  
Darius Zabulionis ◽  
Vytautas Rimša
Keyword(s):  
Mechanical Response ◽  
Volume Fraction ◽  
Three Dimensional ◽  
Particulate Composite ◽  
High Volume ◽  
Spherical Particles ◽  
Particulate Composites ◽  
The Finite Element Method ◽  
Network Method

In the present article, a version of the lattice or spring network method is proposed to model the mechanical response of elastic particulate composites with a high volume fraction of spherical particles and with a much weaker matrix compared to the stiffness of the particles. The main subject of the article is the determination of the axial stiffnesses of the springs of the cell. A comparison of the mechanical response of a three-dimensional particulate composite cube obtained using the finite element method and the proposed methodology showed that the efficiency of the proposed methodology increases with an increasing volume fraction of the particles.

Effective Stiffness of a Debonded Particle in Particulate Composites

2007 ◽  
Vol 334-335 ◽  
pp. 33-36 ◽  
Author(s):  
Akihiro Wada ◽  
Yusuke Nagata ◽  
Shi Nya Motogi
Keyword(s):  
Three Dimensional ◽  
Particulate Composite ◽  
Spherical Particles ◽  
Particulate Composites ◽  
Particle Volume ◽  
Equivalent Inclusion Method ◽  
Equivalent Inclusion ◽  
Load Carrying ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

In this study, partially debonded spherical particles in a particulate composite are analyzed by three-dimensional finite element method to investigate their load carrying capacities, and the way to replace a debonded particle with an equivalent inclusion is examined. The variation in Young’s modulus and Poisson’s ratio of a composite with the debonded angle was evaluated for different particle arrangements and particle volume fractions, which in turn compared with the results derived from the equivalent inclusion method. Consequently, it was found that by replacing a debonded particle with an equivalent orthotropic one, the macroscopic behavior of the damaged composite could be reproduced so long as the interaction between neighboring particles is negligible.

Effect of Structure on Response of a Three-Dimensional-Printed Photopolymer-Particulate Composite Under Intermediate Strain Rate Loading

2020 ◽  
Vol 87 (11) ◽  
Author(s):  
Amirreza Keyhani ◽  
Min Zhou
Keyword(s):  
Strain Rate ◽  
Mechanical Response ◽  
Local Heating ◽  
Three Dimensional ◽  
Particulate Composite ◽  
Deformation Energy ◽  
Material Behavior ◽  
Localized Deformation ◽  
Failure Initiation ◽  
Lagrangian Finite Element

Abstract The thermo-mechanical response of an additively manufactured photopolymer-particulate composite under conditions of macroscopic uniaxial compression without lateral confinement at overall strain rates of 400–2000 s−1 is studied. The material has a direct-ink-written unidirectional structure. Computations are performed to quantify the effects of microstructure attributes including anisotropy, defects, and filament size on localized deformation, energy dissipations, and temperature rises. To this effect, an experimentally informed Lagrangian finite element framework is used, accounting for finite-strain elastic–plastic deformation, strain-rate effect, failure initiation and propagation, post-failure internal contact and friction, heat generation due to friction and inelastic bulk deformation, and heat conduction. The analysis focuses on the material behavior under overall compression. Despite relatively low contribution to overall heating, friction is localized at fracture sites and plays an essential role in the development of local temperature spikes unknown as hotspots. The microstructural attributes are found to significantly affect the development of the hotspots, with local heating most pronounced when loading is transverse to the filaments or when the material has higher porosities, stronger inter-filament junctions, or smaller filament sizes. Samples with smaller filament sizes undergo more damage, exhibit higher frictional dissipation, and develop larger hotspots that occur primarily at failure sites.

VISCOSITY METHOD FOR THE DETERMINATION OF THE THICKNESS OF SOLVATION LAYERS NEAR PARTICLES DISPERSED IN A LIQUID

2005 ◽  
Vol 12 (03) ◽  
pp. 457-462 ◽  
Author(s):  
SHAOXIAN SONG ◽  
YIMIN ZHANG ◽  
TOMLINSON FORT
Keyword(s):  
Size Distribution ◽  
Spherical Particle ◽  
Volume Fraction ◽  
Spherical Particles ◽  
Viscosity Method ◽  
Theoretical Derivation ◽  
Solid Spheres

In this paper, we present a method for determining the thickness of solvation layers near spherical particles dispersed in a liquid through measurements of the viscosity of the dispersion as a function of the volume fraction of the dry particles in the dispersion and the size distribution of the particles. It is termed viscosity method. The theoretical derivation for the method is based on Einstein's theory of viscosity of dispersions, while two assumptions are made: 1. Solvation layers contribute to increasing the viscosity of the dispersion in c times as the same volume of rigid solid spheres. 2. The thickness of solvation layers is the same near every chemically similar spherical particle in a given dispersion.

Computational Evaluation of Effective Conductivity of Particulate Composites with Imperfect Interfaces

2009 ◽  
Vol 631-632 ◽  
pp. 35-40
Author(s):  
M. Zhang ◽  
Peng Cheng Zhai ◽  
Qing Jie Zhang
Keyword(s):  
Thermal Conductivity ◽  
Effective Thermal Conductivity ◽  
Effective Properties ◽  
Effective Conductivity ◽  
Three Dimensional ◽  
Particulate Composite ◽  
Imperfect Interface ◽  
Particulate Composites ◽  
Imperfect Interfaces ◽  
Volume Fractions

This paper is aimed to numerically evaluate the effective thermal conductivity of randomly distributed spherical particle composite with imperfect interface between the constituents. A numerical homogenization technique based on the finite element method (FEM) with representative volume element (RVE) was used to evaluate the effective properties with periodic boundary conditions. Modified random sequential adsorption algorithm (RSA) is applied to generate the three dimensional RVE models of randomly distributed spheres of identical size with the volume fractions up to 50%. Several investigations have been conducted to estimate the influence of the imperfect interfaces on the effective conductivity of particulate composite. Numerical results reveal that for the given composite, due to the existence of an interfacial thermal barrier resistance, the effective thermal conductivity depends not only on the volume fractions of the particle but on the particle size.

scholarly journals Microstructural Evolution and Strengthening Mechanism of SiC/Al Composites Fabricated by a Liquid-Pressing Process and Heat Treatment

Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3374 ◽  
Author(s):  
Sangmin Shin ◽  
Seungchan Cho ◽  
Donghyun Lee ◽  
Yangdo Kim ◽  
Sang-Bok Lee ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Compressive Strength ◽  
Microstructural Evolution ◽  
Load Transfer ◽  
Volume Fraction ◽  
High Volume ◽  
Strengthening Mechanism ◽  
Spherical Particles ◽  
Pressing Process ◽  
Liquid Pressing Process

Aluminum alloy (Al7075) composites reinforced with a high volume fraction of silicon carbide (SiC) were produced by a liquid-pressing process. The characterization of their microstructure showed that SiC particles corresponding to a volume fraction greater than 60% were uniformly distributed in the composite, and Mg2Si precipitates were present at the interface between the matrix and the reinforcement. A superior compressive strength (1130 MPa) was obtained by an effective load transfer to the hard ceramic particles. After solution heat treatment and artificial aging, the Mg2Si precipitates decomposed from rod-shaped large particles to smaller spherical particles, which led to an increase of the compressive strength by more than 200 MPa. The strengthening mechanism is discussed on the basis of the observed microstructural evolution.

Determination of interface integrity in high volume fraction polymer composites at all strain levels

2005 ◽  
Vol 53 (3) ◽  
pp. 647-657 ◽  
Author(s):  
G. Anagnostopoulos ◽  
D. Bollas ◽  
J. Parthenios ◽  
G.C. Psarras ◽  
C. Galiotis
Keyword(s):  
Polymer Composites ◽  
Volume Fraction ◽  
High Volume ◽  
High Volume Fraction

scholarly journals Characterization of the crystal structure, kinematics, stresses and rotations in angular granular quartz during compaction

2018 ◽  
Vol 51 (4) ◽  
pp. 1021-1034 ◽  
Author(s):  
Ryan C. Hurley ◽  
Eric B. Herbold ◽  
Darren C. Pagan
Keyword(s):  
Crystal Structure ◽  
Mechanical Response ◽  
Three Dimensional ◽  
Spherical Particles ◽  
X Ray ◽  
Porosity Evolution ◽  
Individual Grains ◽  
Particle Packings ◽  
Number Of Particles

Three-dimensional X-ray diffraction (3DXRD), a method for quantifying the position, orientation and elastic strain of large ensembles of single crystals, has recently emerged as an important tool for studying the mechanical response of granular materials during compaction. Applications have demonstrated the utility of 3DXRD and X-ray computed tomography (XRCT) for assessing strains, particle stresses and orientations, inter-particle contacts and forces, particle fracture mechanics, and porosity evolution in situ. Although past studies employing 3DXRD and XRCT have elucidated the mechanics of spherical particle packings and angular particle packings with a small number of particles, there has been limited effort to date in studying angular particle packings with a large number of particles and in comparing the mechanics of these packings with those composed of a large number of spherical particles. Therefore, the focus of the present paper is on the mechanics of several hundred angular particles during compaction using in situ 3DXRD to study the crystal structure, kinematics, stresses and rotations of angular quartz grains. Comparisons are also made between the compaction response of angular grains and that of spherical grains, and stress-induced twinning within individual grains is discussed.

scholarly journals A New Equation for the Determination of the Thermal Expansion Coefficient of Particulate Composites

1996 ◽  
Vol 5 (1) ◽  
pp. 096369359600500
Author(s):  
A. R. Boccaccini
Keyword(s):  
Thermal Expansion ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Volume Fraction ◽  
Particulate Composites ◽  
Volume Fractions ◽  
Original Analysis ◽  
Experimental Values ◽  
New Equation

A new equation has been derived for the determination of the thermal expansion coefficient of isotropic particulate composites. An original analysis by Tummala and Friedberg was modified by incorporating the dependence of the internal thermal stress on the inclusion volume fraction, as known from the literature. For low volume fractions of inclusions the new equation gives similar values to the original Tummala and Friedberg equation. For intermediate volume fractions, however (≈0.3 ≤ f ≤ ≈0.7), the present equation is shown to be in better agreement with experimental values for different composite systems investigated.

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