Effect of connectivity on the elasticity of athermal network materials
Effect of connectivity on the elasticity of athermal network materials
复制标题
连接性对无热网络材料弹性的影响
DOI：
10.1039/d2sm01303g
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发表时间：
2022
期刊：
影响因子：
3.4
通讯作者：
Picu, Catalin R.
中科院分区：
文献类型：
--
作者：
Parvez, Nishan;Picu, Catalin R.
具有随机结构的网络材料在生物学和工程学中普遍存在，这推动了当前建立其结构与力学行为之间关系的兴趣。在这项工作中，我们专注于定义的纤维从交联，z的数量的连接性的影响，并比较网络相同（z-均匀）和不同的（z-异构）z的交联。我们观察到，应变刚化的函数形式是z-独立的，并且中心z-依赖的参数是小应变刚度E0。我们证实了以前的结果表明，E0（z）的功能形式是一个权力函数与3个政权，并观察到这适用于一个广泛的z范围。然而，标度指数在z-齐次和z-非齐次情况下是不同的。我们确认，增加Z跨越麦克斯韦的中心力均衡点导致从弯曲到轴向能量存储的过渡。然而，我们观察到，这并不一定意味着变形成为仿射在大z极限。事实上，具有低弯曲刚度的纤维网络保持基于交联的旋转自由度的松弛模式，其允许在大z极限中的E0小于仿射模型预测。我们还得出结论，在z-异构的情况下，平均连接是足够的，以评估连接E0的效果，较高的时刻分布的z是不太重要的。
Network materials with stochastic structure are ubiquitous in biology and engineering, which drives the current interest in establishing relations between their structure and mechanical behavior. In this work we focus on the effect of connectivity defined by the number of fibers emerging from a crosslink, z, and compare networks with identical (z-homogeneous) and distinct (z-heterogeneous) z at the crosslinks. We observe that the functional form of strain stiffening is z-independent, and that the central z-dependent parameter is the small strain stiffness, E0. We confirm previous results indicating that the functional form of E0(z) is a power function with 3 regimes and observe that this applies to a broad range of z. However, the scaling exponents are different in the z-homogeneous and z-heterogeneous cases. We confirm that increasing z across the Maxwell's central force isostatic point leads to a transition from bending to axial energy storage. However, we observe that this does not necessarily imply that deformation becomes affine in the large z limit. In fact, networks of fibers with low bending stiffness retain a relaxation mode based on the rotational degree of freedom of the crosslinks which allows E0 in the large z limit to be smaller than the affine model prediction. We also conclude that in the z-heterogeneous case, the mean connectivity is sufficient to evaluate the effect of connectivity on E0 and that higher moments of the distribution of z are less important.