Effect of Network Architecture on the Mechanical Behavior of Random Fiber Networks
Effect of Network Architecture on the Mechanical Behavior of Random Fiber Networks
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DOI：
10.1115/1.4040245
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发表时间：
2018-08-01
影响因子：
2.6
通讯作者：
Picu, R. C.
中科院分区：
文献类型：
--
作者：
Islam, M. R.;Picu, R. C.
纤维材料在我们周围很普遍。虽然这些系统在微观上类似于随机互连纤维的离散组件，但网络架构因系统而异。为了确定网络结构的作用，我们在这里研究细胞和纤维随机网络在拉伸和压缩，并在大应变弹性的背景下。我们观察到，相比于相同的全球参数集的细胞网络，纤维网络表现出在张力减少应变硬化，减少纤维对齐，并减少泊松收缩在单轴拉伸。这些效应是由于在纤维情况下，每根纤维以交联形式存在大量的运动学约束。小应变模量对网络密度的依赖性在纤维情况下是三次方，在蜂窝情况下是二次方。当纤维情况下的每根纤维的交联数与细胞情况下的每根纤维的交联数相等时，这种差异持续存在，这表明不同的缩放是由于纤维网络的更高的结构无序。两种网络类型在压缩中的行为是相似的，尽管纤维屈曲和应变局部化引起的软化在纤维情况下不太明显。瞬时纤维间接触的贡献在拉伸中很弱，而在压缩中很重要。
Fiber-based materials are prevalent around us. While microscopically these systems resemble a discrete assembly of randomly interconnected fibers, the network architecture varies from one system to another. To identify the role of the network architecture, we study here cellular and fibrous random networks in tension and compression, and in the context of large strain elasticity. We observe that, compared to cellular networks of same global parameter set, fibrous networks exhibit in tension reduced strain stiffening, reduced fiber alignment, and reduced Poisson's contraction in uniaxial tension. These effects are due to the larger number of kinematic constraints in the form of cross-links per fiber in the fibrous case. The dependence of the small strain modulus on network density is cubic in the fibrous case and quadratic in the cellular case. This difference persists when the number of cross-links per fiber in the fibrous case is rendered equal to that of the cellular case, which indicates that the different scaling is due to the higher structural disorder of the fibrous networks. The behavior of the two network types in compression is similar, although softening induced by fiber buckling and strain localization is less pronounced in the fibrous case. The contribution of transient interfiber contacts is weak in tension and important in compression.