The mechanics of embedded fiber networks
The mechanics of embedded fiber networks
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DOI：
10.1016/j.jmps.2023.105456
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发表时间：
2023-10-17
影响因子：
5.3
通讯作者：
Rausch，Manuel
中科院分区：
文献类型：
--
作者：
Kakaletsis，Sotirios;Lejeune，Emma;Rausch，Manuel
光纤网络是众多天然和工程材料力学性能的基础。有趣的是，这些网络通常嵌入在无定形矩阵中，而不是孤立地出现。然而，尽管它们经常以嵌入式而非孤立网络的形式出现，但很少有先前的研究关注于嵌入式在这些系统的紧急机械行为中的作用。为了解决这个问题，我们在有限元框架内采用了迫击炮式嵌入方法，并进行了模拟，以系统地填补这一知识空白。在这项研究中，我们将重点放在软组织上，作为一种典型的材料，其中嵌入式纤维网络对机械功能至关重要。具体来说，我们研究了嵌入对网络中弯曲、拉伸、扭转和剪切纤维级加载模式的应变能分布的作用。其中，我们特别关注半柔性光纤网络。除了揭示嵌入在网络本身的作用外，我们还研究了网络如何影响基质材料的力学。总之，我们发现嵌入从根本上改变了半柔性光纤网络和周围矩阵的机制。最重要的是，我们发现嵌入半柔性纤维网络会导致复合材料的应变增强和负坡印亭效应。此外，半柔性光纤网络在其宿主材料中诱导应力非均质性并增加其抗压缩性。总的来说，我们的工作提高了我们对一类重要材料的基本理解。通过公开我们的实现，我们还希望帮助其他人更多地了解除软组织以外的材料背景下的嵌入式半柔性光纤网络。
Fiber networks underlie the mechanical behavior of a wide range of natural and engineered materials. Interestingly, these networks are often embedded within amorphous matrices rather than appearing in isolation. However, despite their frequent occurrence as embedded rather than isolated networks, few prior studies have focused on investigating the role of embedding on the emergent mechanical behavior of these systems. To address this, we adopt a mortar-type embedding approach within the finite element framework and perform simulations to systematically fill this knowledge gap. Within this study, we focus on soft tissues as an exemplary class of materials where embedded fiber networks are essential to mechanical function. Specifically, we investigate the role of embedding on the strain energy distribution within the networks across the bending, stretching, torsional, and shear fiber-level loading modes. Therein, we specifically focus on semi-flexible fiber networks. In addition to revealing the role of embedding on the networks themselves, we also investigate how the networks affect the mechanics of the matrix material. Together, we find that embedding fundamentally alters the mechanics of semi-flexible fiber networks and the surrounding matrices. Most importantly, we find that embedding semi-flexible fiber networks leads to strain-stiffening and negative Poynting effect of the resulting composite material. Furthermore, semi-flexible fiber networks induce stress heterogeneity in their host material and increase its resistance to compression. Overall, our work improves our fundamental understanding of an important class of materials. By making our implementation openly available, we also hope to help others learn more about embedded semi-flexible fiber networks in the context of materials other than soft tissues.