论文标题
海绵状的摩擦颗粒包装中的刚性结构
Sponge-like rigid structures in frictional granular packings
论文作者
论文摘要
我们通过使用两种识别刚性结构的方法的概括来展示在剪切的摩擦颗粒材料实验中出现刚性。两种方法都是基于力的动力矩阵和基于拓扑的刚性渗透，都彼此一致并确定相似的刚性结构。随着系统的堵塞，接触数为$ z = 2.4 \ pm 0.1 $，这是一个刚刚散布在软盘，充满颗粒的孔中的刚性骨架，出现了各种尺寸，从而形成了海绵样的形态。我们还发现，刚性结构内的压力始终超过刚性结构以外的压力，即骨干是承重的。这些发现表明，有必要超越平均场理论来捕获摩擦干扰的物理学，并表明机械稳定性通过中尺度的拱形结构和铰链产生。
We show how rigidity emerges in experiments of sheared frictional granular materials by using generalizations of two methods for identifying rigid structures. Both approaches, the force-based dynamical matrix and the topology-based rigidity percolation, agree with each other and identify similar rigid structures. As the system becomes jammed, at a contact number of $z=2.4\pm 0.1$, a rigid backbone interspersed with floppy, particle-filled holes of a broad range of sizes emerges, creating a sponge-like morphology. We also find that the pressure within rigid structures always exceeds the pressure outside the rigid structures, i.e. that the backbone is load-bearing. These findings shows that it is necessary to go beyond mean-field theory to capture the physics of frictional jamming and also suggests that mechanical stability arises through arch structures and hinges at the mesoscale.
