Three-dimensional simulations of the complex dielectric properties of random composites by finite element method
Three-dimensional simulations of the complex dielectric properties of random composites by finite element method
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DOI：
10.1063/1.1712017
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发表时间：
2004-06
影响因子：
3.2
通讯作者：
Xuanhe Zhao;Yugong Wu;Z. Fan;Fei Li
中科院分区：
文献类型：
--
作者：
Xuanhe Zhao;Yugong Wu;Z. Fan;Fei Li
使用蒙特卡罗有限元方法模拟由立方晶粒组成的三维结构的二元相随机复合材料的复介电常数。采用Maxwell-Garnett、Bruggeman对称和一般有效介质公式对数值结果进行拟合，并定量评价公式的拟合效率。一般有效介质公式与我们的模拟结果最吻合，其精度优于3.7%。讨论了频率对介电复合材料中静电势空间分布的影响。由于电荷在相间边界附近积累的时间长度不同，低频区和高频区绘制的电势等值线的分布表现出很大的变化。通过改变二元相复合材料中一相的体积分数和损耗特性来绘制介电谱。讨论了介电谱的一般性质，并分析了一定体积分数下两相损耗性质差异引起的介电谱特征。
Complex dielectric constants of binary-phase random composites are simulated for a three-dimensional structure consisting of cubic grains using the Monte Carlo-finite element method. Numerical results are fitted using Maxwell–Garnett, Bruggeman symmetrical, and general effective media formulas, and the fitting efficiencies of the formulas are quantitatively evaluated. The general effective media formula gives the best fitting to our simulation results and its accuracy is better than 3.7%. The effects of frequencies on the spatial distribution of electrostatic potentials in dielectric composites are discussed. The distribution of potential contours drawn in the low-frequency region and the high-frequency region show great variation, because of different lengths of time for charge to accumulate near the interphase boundaries. Dielectric spectra are drawn by varying volume fraction and lossy property of one phase in binary-phase composites. General properties of the dielectric spectra are discussed and the characteristics of the dielectric spectra caused by the differences in the lossy properties of the two phases at certain volume fractions are analyzed.