论文标题
软颗粒包装中的蠕变控制
Creep control in soft particle packings
论文作者
论文摘要
颗粒包装显示出广泛意义的大量机械特征。这些特征之一是蠕变：在施加的应力下缓慢变形。蠕变对于许多其他无定形材料（例如许多金属和聚合物）很常见。蠕变的慢动作是要理解，探测和控制的挑战。我们探测了带有下沉球粘度计的软球包装的蠕变特性。我们发现，在我们的颗粒包装中，蠕变一直持续到大型菌株，并具有具有扩散动态的功率定律形式。蠕变振幅指数依赖于施加的应力和水凝胶的浓度，这表明驾驶和禁闭之间的竞争决定了动力学。我们的结果提供了对软固体的机械性能的见解，而缩放定律为新理论提供了明确的基准，该理论解释了蠕变，并提供了诱人的前景，即可以通过边界应力控制蠕变。
Granular packings display a wealth of mechanical features which are of widespread significance. One of these features is creep: the slow deformation under applied stress. Creep is common for many other amorphous materials such as many metals and polymers. The slow motion of creep is challenging to understand, probe and control. We probe the creep properties of packings of soft spheres with a sinking ball viscometer. We find that in our granular packings, creep persists up to large strains and has a power law form, with diffusive dynamics. The creep amplitude is exponentially dependent on both applied stress and the concentration of hydrogel, suggesting that a competition between driving and confinement determines the dynamics. Our results provide insights into the mechanical properties of soft solids and the scaling laws provide a clear benchmark for new theory that explains creep, and provide the tantalizing prospect that creep can be controlled by a boundary stress.
