三分散颗粒系统冲击过程的数值模拟

Numerical Simulation of Impact Process on Tridisperse Particle System

摘要: 本文采用离散元方法研究三分散颗粒系统在冲击过程中的特性。三分散系统在冲击过程中表现出与单分散系统相似的现象，但在能量传递和颗粒分布方面具有独特特征。大粒径颗粒由于质量较大，倾向于聚集在冲击中心区域，吸收更多的能量；而小粒径颗粒则由于质量较小，更容易向外扩散，表现出多次飞溅现象。中等粒径颗粒的分布介于两者之间，受到惯性和颗粒间相互作用力的共同影响。此外，当颗粒床受到冲击时，冲击球的能量在不同粒径颗粒之间分布不均匀，导致各粒径颗粒的初始动能存在显著差异。在能量耗散的过程中，小粒径颗粒表现出更强的能量回收能力。这种能力使其在下落并撞击颗粒床后能够再次飞溅。相比之下，大粒径颗粒的能量回收能力相对较弱，因此在后续运动中表现出较低的活跃性。

Abstract: This paper employs the discrete element method to investigate the characteristics of a tridisperse particle system during the impact process. The tridisperse system exhibits phenomena similar to those of a monodisperse system during impact, but it demonstrates unique features in terms of energy transfer and particle distribution. Due to their large mass, particles with large diameter tend to accumulate in the central impact region, absorbing more energy, while particles with small diameter, owing to their small mass, are more prone to outward dispersion, exhibiting multiple splash events. The distribution of particles with medium diameter lies between these two extremes, influenced by both inertia and interparticle interaction forces. Additionally, when the granular bed is subjected to impact, the energy of the impact ball is unevenly distributed among particles of different sizes, leading to significant differences in the initial kinetic energy of particles of each size. During the energy dissipation process, particles with small diameter exhibit a stronger energy recovery capability. This ability enables them to splash again after falling and colliding with the particle bed. In contrast, particles with large diameter have relatively weaker energy recovery capabilities, resulting in lower activity in subsequent movements.