Teich Erin G, Galloway K Lawrence, Arratia Paulo E, Bassett Danielle S
Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA.
Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania, Philadelphia, PA 19104, USA.
Sci Adv. 2021 May 12;7(20). doi: 10.1126/sciadv.abe3392. Print 2021 May.
The nature of yield in amorphous materials under stress has yet to be fully elucidated. In particular, understanding how microscopic rearrangement gives rise to macroscopic structural and rheological signatures in disordered systems is vital for the prediction and characterization of yield and the study of how memory is stored in disordered materials. Here, we investigate the evolution of local structural homogeneity on an individual particle level in amorphous jammed two-dimensional (athermal) systems under oscillatory shear and relate this evolution to rearrangement, memory, and macroscale rheological measurements. We define the structural metric crystalline shielding, and show that it is predictive of rearrangement propensity and structural volatility of individual particles under shear. We use this metric to identify localized regions of the system in which the material's memory of its preparation is preserved. Our results contribute to a growing understanding of how local structure relates to dynamic response and memory in disordered systems.
非晶态材料在应力作用下的屈服本质尚未得到充分阐明。特别是，理解微观重排如何在无序系统中产生宏观结构和流变特征，对于预测和表征屈服以及研究记忆如何存储在无序材料中至关重要。在此，我们研究了非晶态二维（无热）堵塞系统在振荡剪切作用下单个颗粒水平上局部结构均匀性的演变，并将这种演变与重排、记忆和宏观流变测量联系起来。我们定义了结构度量晶体屏蔽，并表明它可以预测剪切作用下单个颗粒的重排倾向和结构波动性。我们使用这个度量来识别系统中保留材料制备记忆的局部区域。我们的结果有助于人们进一步理解无序系统中局部结构与动态响应和记忆之间的关系。
