一个软的偏离阻塞:高压下可变形颗粒物质的紧缩
Joel T Clemmer1, Joseph M Monti1, Jeremy B Lechman1
1Sandia National Laboratories, Albuquerque, New Mexico 87185, USA. jtclemm@sandia.gov.
Soft matter
|January 29, 2024
概括
这项研究使用结合颗粒模型模拟了颗粒包装紧缩,揭示了颗粒摩擦和Poisson的作用.
科学领域:
- 计算物理学的计算物理.
- 材料科学是一种材料科学.
- 颗粒力学就是颗粒力学.
背景情况:
- 了解压力下的颗粒材料的行为对于各种工程应用至关重要.
- 传统模型往往简化了谷物相互作用和变形.
- 粘合粒子模型 (BPM) 为模拟颗粒系统提供了更详细的方法.
研究的目的:
- 使用粘合粒子模型 (BPM) 研究3D颗粒包装的高压压缩.
- 分析谷物摩擦和Poisson比对包装分数,协调数和谷物变形的影响.
- 将BPM模拟结果与传统离散元素方法 (DEM) 预测进行比较.
主要方法:
- 模拟3D颗粒包装的高压压缩,使用粘合颗粒模型 (BPM).
- 用键连接的点粒子来表示颗粒,引入多体相互作用以控制波桑比率.
- 在颗粒表面上进行多样化的颗粒排列,以模拟高和低摩擦的颗粒.
- 计算的包装分数,协调号,体积应变,无球性和弹性特性.
主要成果:
- 在低压下,包装分数和协调号显示在堵塞附近的摩擦依赖性.
- 随着包装分数的增加,与低压缩放规律的偏差出现,摩擦效应趋同.
- 颗粒变形 (体积应变和无球性) 遵循依赖于波桑比率的功率规律.
- 在堵塞附近的散装材料的Poisson比率为1/2,降至1/4,然后随着密度增加而增加.
结论:
- 粘合粒子模型 (BPM) 有效地捕捉了颗粒包装中的线性弹性变形.
- 波桑比率在压缩过程中显著影响粒度变形,较高的比率导致体积应变较小,较多的无球性.
- 与传统的DEM相比,BPM结果提供了细微的观点,特别是关于变形和弹性特性作为包装分量的函数.
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