标题： 剪切颗粒流中的粘滑不稳定性：摩擦和声学振动的作用 显示英文标题

标题： Stick-slip instabilities in sheared granular flow: the role of friction and acoustic vibrations

摘要： 我们提出了一种关于密集颗粒材料中剪切流的理论。 该理论的一个关键要素是一种有效温度，它决定了材料对外部驱动力（如剪切应力和振动）的响应方式。 我们表明，在我们的模型中，颗粒之间的摩擦会在中等剪切速率下产生粘滑行为，即使在较大速率下材料是速率强化的。 此外，外部产生的声学振动会改变粘滑振幅，或在特定压力和剪切速率下完全抑制粘滑行为。 我们构建了一个相图，该图指出了在存在和不存在固定振幅和频率的声学振动的情况下，粘滑行为发生的参数范围。 这些结果将微观物理与宏观动力学联系起来，从而为各种颗粒现象提供了有用的信息，包括地震断层上的破裂和滑动、远距离触发的不稳定性以及材料加工中的摩擦控制。 显示英文摘要

摘要： We propose a theory of shear flow in dense granular materials. A key ingredient of the theory is an effective temperature that determines how the material responds to external driving forces such as shear stresses and vibrations. We show that, within our model, friction between grains produces stick-slip behavior at intermediate shear rates, even if the material is rate-strengthening at larger rates. In addition, externally generated acoustic vibrations alter the stick-slip amplitude, or suppress stick-slip altogether, depending on the pressure and shear rate. We construct a phase diagram that indicates the parameter regimes for which stick-slip occurs in the presence and absence of acoustic vibrations of a fixed amplitude and frequency. These results connect the microscopic physics to macroscopic dynamics, and thus produce useful information about a variety of granular phenomena including rupture and slip along earthquake faults, the remote triggering of instabilities, and the control of friction in material processing.