从爬行到流动:在循环剪切下颗粒状材料.
Ye Yuan1, Zhikun Zeng1, Yi Xing1
1School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai, 200240, China.
Nature communications
|May 8, 2024
概括
粗的颗粒状材料总是在剪切下屈服,与简单的玻璃不同. 粒子表面的粗程度显著影响它们的屈服过渡和放松机制,揭示了无形固体中复杂的动态.
科学领域:
- 物理 物理学 物理
- 材料科学 材料科学 材料科学
- 软物质物理学 软物质物理学
背景情况:
- 颗粒状材料与玻璃等无形固体具有结构上的相似之处.
- 在剪切下颗粒状材料的弹性反应和颗粒粗度在产量上的作用仍然不太清楚.
研究的目的:
- 研究颗粒表面粗度对循环剪切下的颗粒材料的屈服过渡和动态的影响.
- 阐明控制颗粒系统行为的放松机制.
主要方法:
- 利用X射线断层扫描来捕捉两个颗粒系统的3D微观动态,其颗粒粗度不同.
- 在不同的剪切幅度 (Γ) 上将系统 subjected to cyclic shear.
主要成果:
- 两种系统都表现出从爬行到扩散动态的过渡,表明颗粒状材料总是产生.
- 在 Γ ≈ 0.1.1 周围的低粗度系统中观察到明显的动态变化,减速和异质性.
- 高粗度系统显示了随着剪切幅度的增加的持续动态演变.
- 在潜在的能源景观上,粗性诱导的微波纹被确定为一个关键因素.
结论:
- 颗粒状材料,特别是粗的材料,不表现出弹性反应,总是屈服,与简单的玻璃形成鲜明对比.
- 颗粒表面的粗性从根本上改变了屈服过渡和放松动态.
- 这项研究突出了现实颗粒材料中存在的复杂和丰富的放松机制.
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