Shojaaee Zahra, Brendel Lothar, Török János, Wolf Dietrich E
Faculty of Physics, University of Duisburg-Essen, 47048 Duisburg, Germany.
Phys Rev E Stat Nonlin Soft Matter Phys. 2012 Jul;86(1 Pt 1):011302. doi: 10.1103/PhysRevE.86.011302. Epub 2012 Jul 6.
The role of rotational degrees of freedom and of microscopic contact properties at smooth walls in two dimensional planar shear has been investigated by contact dynamics simulations of round hard frictional particles. Our default system setup consists of smooth frictional walls, giving rise to slip. We show that there exists a critical microscopic friction coefficient at the walls, above which they are able to shear the granular medium. We observe distinctive features at this critical point, which to our knowledge have not been reported before. Activating rolling friction at smooth walls reduces slip, leading to similar shear behavior as for rough walls (with particles glued on their surface). Our simulations with rough walls are in agreement with previous results, provided the roughness is strong enough. In the limit of small roughness amplitude, however, the distinctive features of shearing with smooth walls are confirmed.
通过对圆形硬摩擦颗粒的接触动力学模拟，研究了二维平面剪切中旋转自由度和平滑壁面微观接触特性的作用。我们的默认系统设置包括光滑的摩擦壁面，会产生滑动。我们表明，壁面上存在一个临界微观摩擦系数，超过该系数，壁面就能剪切颗粒介质。我们在这个临界点观察到了独特的特征，据我们所知，此前尚未有相关报道。在光滑壁面上激活滚动摩擦会减少滑动，导致与粗糙壁面（表面粘贴有颗粒）类似的剪切行为。我们对粗糙壁面的模拟与之前的结果一致，前提是粗糙度足够大。然而，在粗糙度幅值较小的极限情况下，光滑壁面剪切的独特特征得到了证实。
