论文标题
摩擦颗粒链的纠缠组件中的屈服和应变僵硬
Yielding and Strain Stiffening in Entangled Assemblies of Frictional Granular Chains
论文作者
论文摘要
宏观颗粒链的包装捕获了分子聚合物系统的某些基本方面，并已被认为是一种范式，以理解分子尺度的物理学。但是，在这里我们证明了颗粒摩擦$μ$ $ $ $ $ $ $ $ $ $ $ $ $在聚合物系统中没有对应物的颗粒链包装，这会导致非平凡的屈服和流变学反应。基于离散元素模拟，我们研究了在大振幅振荡剪切下颗粒链的随机堆积的非线性流变学。我们发现，剪切变形的最大应力和渗透深度是在$μ$的中间值下，摩擦与极值的非单调函数。我们还表明，相邻谷物之间的定期重复差距（对于商业颗粒链来说都是特殊的），扩大了剪切区并通过促进链之间的互锁事件来增强系统中的纠缠。这些拓扑限制可以显着增加应变僵硬的程度。我们的发现突出了颗粒状链填料和分子聚合物系统的物理学之间的差异。
Packings of macroscopic granular chains capture some of the essential aspects of molecular polymer systems and have been suggested as a paradigm to understand the physics on a molecular scale. However, here we demonstrate that the interparticle friction $μ$ in granular chain packings, which has no counterpart in polymer systems, leads to a nontrivial yielding and rheological response. Based on discrete element simulations we study the nonlinear rheology of random packings of granular chains under large amplitude oscillatory shear. We find that the maximum stress and the penetration depth of the shear deformation into the material bulk are nonmonotonic functions of friction with extrema at intermediate values of $μ$. We also show that the regularly repeated gaps between the adjacent grains, which are special to commercial granular chains, broaden the shear zone and enhance the entanglements in the system by promoting the interlocking events between chains. These topological constraints can significantly increase the degree of strain stiffening. Our findings highlight the differences between the physics of granular chain packings and molecular polymer systems.
