Transport in Stochastic Fibrous Networks
Transport in Stochastic Fibrous Networks
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DOI：
10.1115/1.1322357
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发表时间：
2001
影响因子：
1.2
通讯作者：
X. Cheng;A. Sastry;B. Layton
中科院分区：
文献类型：
--
作者：
X. Cheng;A. Sastry;B. Layton
一些基本问题的随机多孔结构的设计和性能进行检查，源于先进的纤维电极基板在镍氢汽车电池的应用。这些电极必须在数百次充电/放电循环下耐腐蚀和局部失效。这种纤维材料由于其高表面积和高导电性的组合，可以有效地用作化学反应的基底。关键问题之间的关系，连接性和导电性，规模和材料响应的可变性得到解决。两种技术的开发和比较用于预测这些材料的导电性。第一种方法使用统计技术结合经典的微机械模型的适应。第二种方法使用统计生成技术，然后精确计算2D网络电导率。这两种技术相互比较，并与经典的结果。提出了关于这些材料的设计的几个重要结论，包括使用长径比大于至少50的纤维的重要性，单向导电性的适度对齐的弱效果，以及在可能的行为范围内导电性与体积分数的弱幂律行为。
Some fundamental issues concerning the design and performance of stochastic porous structures are examined, stemming from application of advanced fibrous electrode substrates in NiMH automotive cells. These electrodes must resist corrosion and local failures under hundreds of charge/discharge cycles. Such fibrous materials can be effectively used as substrates for chemical reactions because of their combinations of high surface area and high conductivity. Key questions concerning the relationships among connectivity and conductivity, scale and variability in material response are addressed. Two techniques are developed and compared for use in predicting these materials' conductivity. The first approach uses a statistical technique in conjunction with an adaptation of classic micromechanical models. The second approach uses the statistical generation technique, followed by an exact calculation of 2D network conductivity. The two techniques are compared with one another and with classic results. Several important conclusions about the design of these materials are presented, including the importance of use of fibers with aspect rations greater than at least 50, the weak effect of moderate alignment for unidirectional conductivity, and the weak power-law behavior of conductivity versus volume fraction over the range of possible behaviors.