Vo Thanh-Trung, Nguyen Trung-Kien
School of Transportation Engineering, Danang Architecture University, 566 Nui Thanh Street, Da Nang City, Vietnam.
Office of Research Administration, Danang Architecture University, 566 Nui Thanh Street, Da Nang City, Vietnam.
Phys Rev E. 2022 Jul;106(1-1):014902. doi: 10.1103/PhysRevE.106.014902.
Penetration of intruders into granular packings is well described by separately considering the dry or wet case of granular environments in previous experiments and simulations; however, the unified description of such penetration depth in these two granular media remains elusive due to lacking clear explanations about its origins. Based on three-dimensional discrete element method simulations, we introduce a power-law fitting form of the final penetration depth of a spherical intruder with low velocity vertically penetrating into dry and wet granular packings, excellently expressed on a master curve as a power-law function of a dimensionless impact number that is defined as the square root of the ratio between the inertial stress of the intruder and the linear combination of the mean gravitational stress and the cohesive stress exerted on each grain in the packings, as a remarkable extension of the inertial number in dry granular flows. This scaling robustly provides physical insights inherent in the unified description of the material properties of granular packings and the impactor penetration conditions on the final penetration depth in the impact tests, providing evidence of impact properties in different disciplines and applications in science and engineering.
在先前的实验和模拟中，通过分别考虑颗粒环境的干燥或湿润情况，入侵者穿透颗粒填料的情况得到了很好的描述；然而，由于缺乏对其起源的清晰解释，这两种颗粒介质中这种穿透深度的统一描述仍然难以捉摸。基于三维离散元方法模拟，我们引入了一种幂律拟合形式，用于描述低速球形入侵者垂直穿透干燥和湿润颗粒填料的最终穿透深度，该深度在主曲线上出色地表示为无量纲冲击数的幂律函数，无量纲冲击数定义为入侵者的惯性应力与填料中施加在每个颗粒上的平均重力应力和内聚应力的线性组合之比的平方根，这是干颗粒流中惯性数的显著扩展。这种标度有力地提供了颗粒填料材料特性统一描述以及冲击试验中冲击器穿透条件对最终穿透深度影响的内在物理见解，为不同学科的冲击特性以及科学和工程中的应用提供了证据。
