scholarly journals Research on the Homogenized Postirradiation Elastoplastic Constitutive Relations for Composite Nuclear Fuels

2021 ◽  
Vol 8 ◽  
Author(s):  
Jing Zhang ◽  
Jingyu Zhang ◽  
Haoyu Wang ◽  
Hongyang Wei ◽  
Changbing Tang ◽  
...  
Keyword(s):  
Metal Matrix ◽  
Volume Fraction ◽  
Constitutive Relations ◽  
Particle Volume Fraction ◽  
Tensile Tests ◽  
Uniaxial Tensile ◽  
Particle Volume ◽  
Plastic Deformations ◽  
Wide Range ◽  
Irradiation Process

A multi-scale finite element method is developed to simulate the irradiation process and postirradiation uniaxial tensile tests for metal-matrix composite fuels with representative volume elements (RVEs). The simulations of irradiation process are implemented under a wide range of burnup levels, with the irradiation effects on the mechanical constitutive relations of fuel particles and matrix taken into account comprehensively. The simulation results for the macroscopic postirradiation true stress/strain curves are obtained, excluding the irradiation-induced macroscopic deformations. The effects of particle fission density, temperature, and initial particle volume fraction are investigated and analyzed. The research results indicate that 1) a quasi-elastic stage appears during the postirradiation tension, which is mainly induced by the creation of high residual compressive stresses in the particles and matrix after irradiation; 2) with the increase of effective strains, new plastic deformations increase in the particles and matrix to result in the macroscale plastic stage; 3) the macroscale irradiation softening and hardening phenomena appear, which mainly stem from the weakened deformation resistance by the irradiation-induced plastic deformations in the matrix, the enlarged particle volume fraction after irradiation, and the irradiation hardening effects of metal matrix.

3D Micro-Structural Modeling of Vibration Characteristics of Smart Particle-Reinforced Metal-Matrix Composite Beams

2019 ◽  
Vol 19 (07) ◽  
pp. 1950078
Author(s):  
Recep Ekici ◽  
Vahdet Mesut Abaci ◽  
J. N. Reddy
Keyword(s):  
Particle Size ◽  
Metal Matrix Composite ◽  
Metal Matrix ◽  
Vibration Amplitude ◽  
Natural Frequencies ◽  
Particle Distribution ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Particle Volume ◽  
Random Particle

In this study, the effects of micro-structural parameters such as particle volume fraction, size and random distribution of Al 6061/SiC particulate metal-matrix composite (MMC) beams on free vibration response and the active vibration control are investigated. For this purpose, numerical particle-reinforced MMC (PRMMC) beam specimens were modeled with 3D finite elements, and the cubic-shaped reinforcing SiC particles were randomly distributed in Al 6061 metal matrix similar to an actual micro-structure. The particle size and especially volume fraction play an important role on the natural frequencies of the smart PRMMCs although they have no effect on the mode shapes. The random particle distribution has minor effect on the natural frequencies of the smart PRMMCs. With the increase of the feedback control gain, both the vibration amplitude and the suppression time are reduced reasonably. Increasing the particle volume fraction induces an important reduction in the damping time and the vibration amplitude for both the controlled and uncontrolled damped vibrations. Finally, increasing the particle size decreases the vibration suppression capacity and increases the vibration amplitude and time slightly. Random particle distribution had no obvious effect on the uncontrolled and controlled vibrations.

Finite Element Simulation of Metal Matrix Composites: Effective Coefficients of Friction and Temperature Fields Under Frictional Loading

2005 ◽  
Author(s):  
Christopher O. Huber ◽  
Sascha Kremmer ◽  
Heinz E. Pettermann
Keyword(s):  
Finite Element ◽  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Matrix Composites ◽  
Particle Volume ◽  
First Case ◽  
Effective Coefficients ◽  
Unit Cells

Computational predictions on the tribological behavior of metal matrix composites (MMCs) are carried out. The influence of particle volume fraction and clustering of particles is investigated at different length scales. Finite Element simulations are performed on unit cells utilizing approaches from the field of ‘continuum mechanics of materials’. Models are based on the work of Segurado et al. [1], who used homogeneous, randomly distributed inclusions in a matrix phase with 30% particle volume fraction. In addition, the present work introduces modified unit cells with 10% volume fraction, with both homogeneous random and clustered distribution (Fig. 1). These modifications are derived from the original cell by either randomly removing inclusions in the first case, or from a predefined area in the second case.

Finite Element Analysis about Effects of Particle Size on Deformation Behavior of Particle Reinforced Metal Matrix Composites

2007 ◽  
Vol 353-358 ◽  
pp. 1263-1266
Author(s):  
Yi Wu Yan ◽  
Lin Geng ◽  
Ai Bin Li ◽  
Guo Hua Fan
Keyword(s):  
Particle Size ◽  
Finite Element ◽  
Metal Matrix Composites ◽  
Deformation Behavior ◽  
Metal Matrix ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Matrix Composites ◽  
Particle Volume ◽  
Element Analysis

By incorporating the Taylor-based nonlocal theory of plasticity, the finite element method (FEM) is applied to investigate the effect of particle size on the deformation behavior of the metal matrix composites. In the simulation, the two-dimensional plane strain and random distribution multi-particles model are used. It is shown that, at a fixed particle volume fraction, there is a close relationship between the particle size and the deformation behavior of the composites. The yield strength and plastic work hardening rate of the composites increase with decreasing particle size. The predicted stress-strain behaviors of the composites are qualitative agreement with the experimental results.

Characterization of Indentation-Induced “Particle Crowding” in Metal Matrix Composites

Materials ◽  
2004 ◽  
Author(s):  
R. Pereyra ◽  
Y.-L. Shen
Keyword(s):  
Cross Sections ◽  
Metal Matrix ◽  
Particle Concentration ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Primary Objective ◽  
Indentation Hardness ◽  
Particle Volume ◽  
Element Analysis

A direct experimental characterization of reinforcement configuration in an indentation-deformed metal matrix composite is undertaken. The primary objective is to quantify the possible local increase in particle concentration, which has been proposed to cause inconsistency in the indentation hardness and the overall composite strength. Quantitative metallography on the post-indented material is carried out to measure the particle volume fraction. Multiple cross sections of an indentation are investigated with statistically significant results obtained. A distinct increase in particle concentration induced by the indentation is found. The spatial distribution of particle concentration is also examined in detail. The residual compressive stress field remained in the material upon unloading, as illustrated by the finite element analysis, is shown to be in qualitative agreement with the measurement.

The effect of high TiC particle content on the tensile cracking and corrosion behavior of Al–5Cu matrix composites

2019 ◽  
Vol 54 (13) ◽  
pp. 1681-1690 ◽  
Author(s):  
Burak Dikici ◽  
Fevzi Bedir ◽  
Mehmet Gavgali
Keyword(s):  
Corrosion Behavior ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Tensile Tests ◽  
Matrix Composites ◽  
Particle Volume ◽  
The Matrix ◽  
Tic Particle ◽  
Mechanical Properties And Corrosion ◽  
Tic Particulates

The high-TiC particle volume fraction on the mechanical properties and corrosion behavior of the A–5Cu matrix composites were investigated with porosity, hardness, tensile tests, and polarization measurements. The composites reinforced with 18, 27, and 50 vol% TiC particulates were produced successfully by using hot-pressing technique under Ar atmosphere and characterized by scanning electron microscope, electron dispersive spectroscope, and X-ray diffraction. The corrosion susceptibilities of the composites were compared with potentiodynamic scanning technique. It was found that the hardness of the composites increases while the fracture strength decreases with increasing TiC reinforcement content in the matrix. The corrosion susceptibilities of 18 and 27 vol% TiC-reinforced composites are almost the same; the corrosion rate of 50 vol% TiC-reinforced composite was approximately 10 times higher than the composites reinforced with 18 and 27 vol% TiC particles in the 3.5% NaCl. In addition, some preferential corrosion attacks were detected at TiC/matrix interfaces and in TiC clusters during the corrosion process of the composites. Therefore, the porosity content in the composites was almost the same level.

scholarly journals Study on Microstructure Effect of Carbon Black Particles in Filled Rubber Composites

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Li Hong Huang ◽  
Xiaoxiang Yang ◽  
Jianhong Gao
Keyword(s):  
Particle Size ◽  
Carbon Black ◽  
Polymer Nanocomposites ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Uniaxial Tensile ◽  
Particle Volume ◽  
Carbon Particles ◽  
The Difference ◽  
Microstructure Effect

The cross sections of blended natural/styrene-butadiene (NSBR) composites filled with different volume fractions of carbon particles were observed using a Quanta 250 scanning electron microscope. In addition, the sizes and distributions of the carbon particles were analyzed using Nano Measurer. A two-dimensional representative volume element model (RVE) for a rubber composite reinforced with circular carbon particles was established, and the uniaxial tensile behaviors of polymer nanocomposites with different particle size distribution patterns were simulated using the ABAQUS software. The results showed the following. (1) For the random models, if the difference of particle size was larger and particle distance was closer, stress distribution would be denser as well as the stress concentration would become greater. However, if the difference of particle size was small, for the case of same particle volume fraction, the particle size has little influence on the macromechanical properties whether the average size is large or small. (2) The correlation between the volume fraction and distribution of the carbon particles revealed that when the volume fraction of carbon black particles was larger than 12%, clusters between carbon particles in the polymer nanocomposites could not be avoided and the modulus of the composites increased with an increase in the cluster number.

Effect of Strain Gradients and Heterogeneity on Flow Strength of Particle Reinforced Metal-Matrix Composites

2002 ◽  
Vol 124 (2) ◽  
pp. 167-173 ◽  
Author(s):  
D-M. Duan ◽  
N. Q. Wu ◽  
M. Zhao ◽  
W. S. Slaughter ◽  
Scott X. Mao
Keyword(s):  
Particle Size ◽  
Metal Matrix Composites ◽  
Strain Gradient ◽  
Metal Matrix ◽  
Volume Fraction ◽  
Cell Model ◽  
Particle Volume Fraction ◽  
Matrix Composites ◽  
Particle Volume ◽  
Flow Strength

This paper deals with an analysis of the size effect on the flow strength of metal-matrix composites due to the presence of geometrically necessary dislocations. The work is based upon a cell model of uniaxial deformation. The deformation field is analyzed based on a requirement of the deformation compatibility along the interface between the particle and the matrix, which in turn is completed through introducing an array of geometrically necessary dislocations. The results of modelling show that the overall stress-strain relationship is dependent not only on the particle volume fraction but also on the particle size. It has been found that the material length scale in the strain gradient plasticity is dependent on the particle volume fraction, or in other words, on the relative ratio of the particle spacing to the particle size. The strain gradient is, besides the macro-strain and the particle volume fraction, inversely proportional to the particle size.

scholarly journals Microstructure Characterization of Aluminium Syntactic Functionally Graded Composites Containing Hollow Ceramic Microspheres Manufactured by Radial Centrifugal Casting

2008 ◽  
Vol 587-588 ◽  
pp. 207-211 ◽  
Author(s):  
S.C. Ferreira ◽  
Alexandre Velhinho ◽  
L.A. Rocha ◽  
Francisco Manuel Braz Fernandes
Keyword(s):  
Metal Matrix ◽  
Radial Direction ◽  
Volume Fraction ◽  
Centrifugal Casting ◽  
Particle Volume Fraction ◽  
Particle Diameter ◽  
Functionally Graded ◽  
Particle Volume ◽  
Centrifugally Cast ◽  
Functionally Graded Composites

Syntactic functionally graded metal matrix composites (SFGMMC) are a class of metallic foams in which closed porosity results from the presence of hollow ceramic microspheres (microballoons), whose spatial distribution varies continuously between the inner and the outer section of the part, thus resulting in a continuous variation in properties. In this work, aluminiumbased SFGMMC rings were fabricated by radial centrifugal casting. The graded composition along the radial direction is controlled mainly by the difference in the centrifugal forces which act on the molten metal matrix and the ceramic particles, due to their dissimilar densities. In this case where the density of the SiO2-Al2O3 microballoons is lower than that of molten aluminium, the particles show a tendency to remain closer to the inner periphery of the ring. Thus the microballoon volume fraction increases along the radial direction of the ring from the outer to the inner periphery; in other words, the particle-rich zone is limited to an inner layer of the ring. Precursor conventional MMCs were prepared by stir-casting from the constituent materials, by homogeneously dispersing commercial SiO2-Al2O3 microballoons (particle size: 50 µm; particle volume fraction: 5 and 10 %) within a molten commercial Al-7Si-0.3Mg (A356) alloy. The resulting MMCs were then re-melt and centrifugally cast in order to produce the functionally graded composites. Particle gradients in the centrifugally cast composites were investigated by quantitative image analysis of optical micrographs (for the estimation of the particle volume fraction, mean particle diameter and porosity volume fraction).

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