论文标题
通过流动润滑在流量异质性下，剪切波诱导的颗粒培养基中的软化和同时压实
Shear-wave-induced softening and simultaneous compaction in dense granular media through acoustic lubrication at flow heterogeneities
论文作者
论文摘要
我们报告了声音共振实验中受约束颗粒包的同时软化和压实。随着波幅度的增加，剪切波速度的降低表现出弹性软化。未观察到晶粒或膨胀的宏观重排；取而代之的是，弹性软化伴随着晶粒浅层的尺寸上的少量压实。我们使用基于剪切转化区（STZ）的理论模型，软点和滑动接触的理论模型来解释这些明显的矛盾观察。它可以预测由于小振幅声振荡而导致的线性剪切应力应变响应，可忽略不计的宏塑性变形。然而，这些波通过谷物接触的声学润滑减少了颗粒摩擦，并降低了接触刚度，从而导致结构障碍或压实性和动态模量的软化增加。与这种微观摩擦降低相关的压实与通过亚元素状态中的STZ之间的类似ISIN样相关性的预测一致。
We report the simultaneous softening and compaction of a confined dense granular pack in acoustic resonance experiments. Elastic softening is manifested by a reduction of the shear-wave speed, as the wave amplitude increases beyond some threshold. No macroscopic rearrangement of grains or dilatancy is observed; instead, elastic softening is accompanied by a tiny amount of compaction on the scale of grain asperities. We explain these apparent contradictory observations using a theoretical model, based on shear transformation zones (STZs), of soft spots and slipping contacts. It predicts a linear shear stress-strain response with negligible macro-plastic deformation due to the small-amplitude acoustic oscillation. However, these waves reduce the interparticle friction and contact stiffness through the acoustic lubrication of grain contacts, resulting in an increase in the structural disorder or compactivity and softening of dynamic modulus. The compaction associated with this microscopic friction decrease is consistent with the prediction by an Ising-like correlation between STZs in the subyield regime.
