Energy dissipation and dispersion effects in granular media.
Energy dissipation and dispersion effects in granular media.
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DOI：
10.1103/physreve.78.031307
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发表时间：
2008-09
期刊：
影响因子：
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通讯作者：
Zhen Zhao;Caishan Liu;B. Brogliato
中科院分区：
文献类型：
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作者：
Zhen Zhao;Caishan Liu;B. Brogliato
颗粒间的强相互作用将使颗粒材料内部的能量通过接触网络传播并部分耗散。建立一个能够清晰区分耗散和弥散效应的模型对于理解颗粒材料的整体行为是至关重要的。对于具有与速率无关的材料的颗粒，耗散效应来自局部塑性变形，并且可以通过使用能量恢复系数在能量水平上进行约束。另一方面，色散效应应取决于两个粒子之间相互作用定律的内在性质。在一个双刚度柔性接触模型，服从由能量系数定义的能量约束，我们最近的工作有关的问题的多次碰撞表明，在碰撞过程中的能量传播可以表示为一个分布律。特别是，该定律表明，分散效果是由相对接触刚度和相对势能存储在接触点。在本文中，我们将应用我们的理论来研究颗粒链系统中的波动行为。数值结果与Falcon，[Eur. Phys.J. B 5，111（1998）]中的计算结果与Falcon的结果吻合得很好，并证实了Falcon的一些结论。还给出了与多个粒子碰撞链的情况以及赫兹型链中两个所谓的孤立波之间的碰撞有关的其他数值结果。
The strong interactions between particles will make the energy within the granular materials propagate through the network of contacts and be partly dissipated. Establishing a model that can clearly classify the dissipation and dispersion effects is crucial for the understanding of the global behaviors in the granular materials. For particles with rate-independent material, the dissipation effects come from the local plastic deformation and can be constrained at the energy level by using energetic restitution coefficients. On the other hand, the dispersion effects should depend on the intrinsic nature of the interaction law between two particles. In terms of a bistiffness compliant contact model that obeys the energetical constraint defined by the energetic coefficients, our recent work related to the issue of multiple impacts indicates that the propagation of energy during collisions can be represented by a distributing law. In particular, this law shows that the dispersion effects are dominated by the relative contact stiffness and the relative potential energy stored at the contact points. In this paper, we will apply our theory to the investigation of the wave behavior in granular chain systems. The comparisons between our numerical results and the experimental ones by Falcon, [Eur. Phys. J. B 5, 111 (1998)] for a column of beads colliding against a wall show very good agreement and confirm some conclusions proposed by Falcon Other numerical results associated with the case of several particles impacting a chain, and the collisions between two so-called solitary waves in a Hertzian type chain are also presented.