Ripplocations: A universal deformation mechanism in layered solids
Ripplocations: A universal deformation mechanism in layered solids
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DOI：
10.1103/physrevmaterials.3.013602
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发表时间：
2019-01-02
影响因子：
3.4
通讯作者：
Tucker, G. J.
中科院分区：
文献类型：
--
作者：
Barsoum, M. W.;Zhao, X.;Tucker, G. J.
层状固体在自然界中无处不在：从亚纳米石墨烯和云母层，到厘米级的木材、层压复合材料和纸板，再到公里级的地质构造。虽然后两者之间的相似之处已被认识到[Budd et al., Philos.跨。 R.苏克。 A 370,1723 (2012)]，但没有同样的物理原理适用于晶体固体的原子层尺度。在此，结合石墨的原子模拟和对各种层状固体（塑料卡、薄钢和铝片）进行简单仪器圆柱形压痕实验，我们表明，在所有情况下，受限屈曲都会导致不稳定性，从而导致多个符号相反的波纹边界成核，这些边界以波状方式快速从压头下方传播开。至关重要的是，卸载后，它们会在消散大量摩擦能后消失。了解波纹成核、自组装和传播是了解大多数层状固体变形的基础。
Layered solids are ubiquitous in nature: from subnanometer graphene and mica layers, to wood, laminated composites, and paperboard at the centimeter scale, to geologic formations at the kilometer range. And while the similarities between the latter two have been recognized [Budd et al., Philos. Trans. R. Soc. A 370,1723 (2012)], what has not is that the same physics applies at the atomic-layer scale of crystalline solids. Herein, using a combination of atomistic simulations of graphite and simple instrumented cylindrical indentation experiments on various layered solids-plastic cards, thin steel, and Al sheets-we show that in all cases, confined buckling results in an instability that leads to the nucleation of multiple, oppositely signed ripplocation boundaries that rapidly propagate away from under the indenter in a wavelike manner. Crucially, upon unloading, they disappear, after dissipating considerable amounts of frictional energy. Understanding ripplocation nucleation, self-assembly, and propagation is fundamental to understanding the deformation of most layered solids.