The influence of imperfect interfaces on the measurable effective properties of ceramic composites

2021 ◽  
pp. 1-20
Author(s):  
Gabriella Bolzon ◽  
Pandi Pitchai
Keyword(s):  
Effective Properties ◽  
Ceramic Composites ◽  
Imperfect Interfaces

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.

Effective properties of cement-based porous piezoelectric ceramic composites

2018 ◽  
Vol 190 ◽  
pp. 1208-1214 ◽  
Author(s):  
J. Sladek ◽  
P. Novak ◽  
P.L. Bishay ◽  
V. Sladek
Keyword(s):  
Piezoelectric Ceramic ◽  
Effective Properties ◽  
Ceramic Composites

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.

Effects of Variable Phase Volume Fractions on the Effective Thermo-Mechanical Properties of Metal-Ceramic Composites With Graded Microstructures

2015 ◽  
Author(s):  
Phillip Deierling ◽  
Olesya I. Zhupanska ◽  
Crystal Pasiliao
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Volume Fraction ◽  
Effective Properties ◽  
Ceramic Composites ◽  
Material Composition ◽  
Linear Quadratic ◽  
Temperature Dependent ◽  
Element Analysis ◽  
Micromechanics Models

The present paper is specifically concerned with the evaluation of the effective temperature-dependent elastic, thermal and thermo-elastic material properties of artificially graded Ti-TiB2 microstructures (through thickness only). Effective properties of Ti-TiB2 composite are obtained using micromechanics models and finite element analysis of representative volume elements (RVEs). Two approaches have been adopted and compared to determine the proper RVE. In a fashion similar to previous studies [1], RVEs are generated by considering regions that have a uniform to slow variation in material composition (i.e., constant volume fraction), resulting in statistically homogenous piece-wise RVEs of the graded microstructure neglecting interaction from neighboring cells. In the second approach, continuous RVEs are generated by considering the entire FGM. As pointed out by Anthoine [2], modeling of the complete variation in a microstructure may influence the surrounding layers due to the interactions of varying material composition, particularly when there is a steep variation in material composition along the grading direction. To determine these effects of interlayer interactions, FGM microstructures were generated using three different types of material grading functions, linear, quadratic and square root, providing uniform, gradual and steep variations, respectively. Finite element analysis was performed to determine effective properties of the composite over a wide temperature range.

Matrix Cracking With Irregular Fracture Fronts as Observed in Fiber Reinforced Ceramic Composites

1998 ◽  
Vol 120 (1) ◽  
pp. 79-85
Author(s):  
Kai X. Hu ◽  
Chao-pin Yeh ◽  
Karl W. Wyatt
Keyword(s):  
Effective Properties ◽  
Crack Density ◽  
Crack Size ◽  
Ceramic Composites ◽  
Matrix Cracking ◽  
Fiber Reinforced Composites ◽  
Reinforced Composites ◽  
Fiber Reinforced ◽  
Penny Shaped Crack ◽  
Shaped Crack

As a result of matrix cracking in fiber reinforced composites, fracture planforms assume a wide variation of profiles due to the fact that fiber bridging strongly affects the behavior of local crack fronts. This observation raises the question on the legitimacy of commonly used penny-shaped crack solutions when applied to fiber reinforced composites. Accordingly, investigation of the effects of fracture front profiles on mechanical responses is the thrust of this paper. We start with the solution of a penny-shaped crack in a unidirectional, fiber reinforced composite, which demonstrates necessarity of considering wavy fracture fronts in fiber reinforced composites. A theoretical framework for fiber reinforced composites with irregular fracture fronts due to matrix cracking is then established via a micromechanics model. The difference between small crack-size matrix cracking and large crack-size matrix cracking is investigated in detail. It is shown that the bridging effect is insignificant when matrix crack size is small and solution of effective property are obtained using Mori-Tanaka’s method by treating cracks and reinforcing fibers as distinct, but interacting phases. When the crack size becomes large, the bridging effects has to be taken into consideration. With bridging tractions obtained in consistency with the micromechanics solution, and corresponding crack energy backed out, the effective properties are obtained through a modification of standard Mori-Tanaka’s treatment of multiphase composites. Analytical solutions show that the generalization of a crack density of a penny-shaped planform is insufficient in describing the effective responses of fiber-reinforced composites with matrix cracking. Approximate solutions that account for the effects of the irregularity of crack planforms are given in closed forms for several irregular crack planforms, including cracks of cross rectangle, polygon and rhombus.

scholarly journals Size dependent of the effective conductivity of composite with imperfect interfaces

2020 ◽  
Author(s):  
Nguyen Trung Kien
Keyword(s):  
Fourier Transform ◽  
Size Effect ◽  
Effective Properties ◽  
Effective Conductivity ◽  
Imperfect Interface ◽  
Numerical Results ◽  
Imperfect Interfaces ◽  
Size Dependent ◽  
Equivalent Inclusion ◽  
The Fourier Transform

Based on the circle assemblage model, the effective properties of the inclusion with imperfect interface are derived. The equivalent inclusion is incorporated in the Fourier Transform algorithm to determine the effective conductivity of the composite with lowly conducting or highly conducting interface. The size effect is considered for both cases. Numerical results are provided to illustrate the dependence of the effective conductivity on the size of inhomogeneities.

Polymer-derived SiCN composites with magnetic properties

2003 ◽  
Vol 18 (11) ◽  
pp. 2549-2551 ◽  
Author(s):  
Atanu Saha ◽  
Sandeep R. Shah ◽  
Rishi Raj ◽  
Stephen E. Russek
Keyword(s):  
Magnetic Properties ◽  
Low Temperature ◽  
Low Cost ◽  
Ceramic Composites ◽  
Processing Method ◽  
Silicon Carbonitride ◽  
Imperfect Interfaces ◽  
Elastic Resistance ◽  
Low Temperature Processing ◽  
Multifunctional Properties

Composites consisting of particles of α-iron dispersed in silicon carbonitride (SiCN) were fabricated by a polymer route. The composites had iron inclusions with the same magnetization as bulk iron, but they resisted oxidation up to 500°C and had a hardness of 5-7 GPa. The composites behaved as ferromagnets, albeit with a low susceptibility attributed to the pinning of the domains by imperfect interfaces and to the elastic resistance from the SiCN matrix. This low-cost, low-temperature processing method can be used to make different kinds of ceramic composites with multifunctional properties.

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