Conzelmann N A, Penn A, Partl M N, Clemens F J, Poulikakos L D, Müller C R
ETH Zürich, Laboratory of Energy Science and Engineering, Department of Mechanical and Process Engineering, Institute of Energy and Process Engineering, Leonhardstrasse 21, 8092 Zürich, Switzerland.
Empa-Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, 8600 Dübendorf, Switzerland.
Phys Rev E. 2020 Dec;102(6-1):062902. doi: 10.1103/PhysRevE.102.062902.
An external load on a particle packing is distributed internally through a heterogeneous network of particle contacts. This contact force distribution determines the stability of the particle packing and the resulting structure. Here, we investigate the homogeneity of the contact force distribution in packings of highly nonconvex particles both in two-dimensional (2D) and three-dimensional (3D) packings. A recently developed discrete element method is used to model packings of nonconvex particles of varying sphericity. Our results establish that in 3D packings the distribution of the contact forces in the normal direction becomes increasingly heterogeneous with decreasing particle sphericity. However, in 2D packings the contact force distribution is independent of particle sphericity, indicating that results obtained in 2D packings cannot be extrapolated readily to 3D packings. Radial distribution functions show that the crystallinity in 3D packings decreases with decreasing particle sphericity. We link the decreasing homogeneity of the contact force distributions to the decreasing crystallinity of 3D packings. These findings are complementary to the previously observed link between the heterogeneity of the contact force distribution and a decreasing packing crystallinity due to an increasing polydispersity of spherical particles.
颗粒填充物上的外部负载通过颗粒接触的异质网络在内部进行分布。这种接触力分布决定了颗粒填充物的稳定性及由此产生的结构。在此，我们研究高度非凸颗粒在二维（2D）和三维（3D）填充物中接触力分布的均匀性。采用最近开发的离散元方法对不同球形度的非凸颗粒填充物进行建模。我们的结果表明，在3D填充物中，随着颗粒球形度降低，法向接触力分布变得越来越不均匀。然而，在2D填充物中，接触力分布与颗粒球形度无关，这表明在2D填充物中获得的结果不能轻易外推到3D填充物。径向分布函数表明，3D填充物中的结晶度随颗粒球形度降低而降低。我们将接触力分布均匀性的降低与3D填充物结晶度的降低联系起来。这些发现补充了之前观察到的由于球形颗粒多分散性增加导致接触力分布不均匀性与填充物结晶度降低之间的联系。
