论文标题
在颗粒物中，摩擦对于膨胀和剪切干扰至关重要吗？
Is friction essential for dilatancy and shear jamming in granular matter?
论文作者
论文摘要
颗粒包装显示出显着的膨胀现象[1]，其中它们的体积在剪切变形时增加。传统的智慧和先前的结果表明，延伸性以及剪切引起的干扰的相关现象需要摩擦相互作用[2，3]。在这里，我们研究了无摩擦包装中膨胀和剪切堵塞的发生。我们表明，在最小密度高于J点密度ϕJ [4，5]上方的各向同性干扰密度ϕJ [4，5]都导致剪切诱导的干扰和膨胀的出现。 ϕJ处的包装形成一个明显的阈值状态，在恒定压力剪切下，系统在消失压力的极限中演变成，而与初始干扰密度ϕJ无关。尽管不同ϕJ的包装在压缩下显示出等效的缩放特性[6]，但它们在剪切下的流变行为表现出明显的差异。当ϕJ> ϕJJ时，恒定体积下的屈服应力随着密度不断增加，这与在ϕJ处堵塞的通用包装中的连续行为相反[4，7]。
Granular packings display the remarkable phenomenon of dilatancy [1], wherein their volume increases upon shear deformation. Conventional wisdom and previous results suggest that dilatancy, as also the related phenomenon of shear-induced jamming, requires frictional interactions [2, 3]. Here, we investigate the occurrence of dilatancy and shear jamming in frictionless packings. We show that the existence of isotropic jamming densities ϕj above the minimal density, the J-point density ϕJ [4, 5], leads both to the emergence of shear-induced jamming and dilatancy. Packings at ϕJ form a significant threshold state into which systems evolve in the limit of vanishing pressure under constant pressure shear, irrespective of the initial jamming density ϕj. While packings for different ϕj display equivalent scaling properties under compression [6], they exhibit striking differences in rheological behaviour under shear. The yield stress under constant volume shear increases discontinuously with density when ϕj > ϕJ, contrary to the continuous behavior in generic packings that jam at ϕJ [4, 7].
