Department of Chemistry, Duke University, Durham, NC 27710;
Department of Physics, Syracuse University, Syracuse, NY 13244.
Proc Natl Acad Sci U S A. 2021 May 4;118(18). doi: 10.1073/pnas.2019909118.
The similarity in mechanical properties of dense active matter and sheared amorphous solids has been noted in recent years without a rigorous examination of the underlying mechanism. We develop a mean-field model that predicts that their critical behavior-as measured by their avalanche statistics-should be equivalent in infinite dimensions up to a rescaling factor that depends on the correlation length of the applied field. We test these predictions in two dimensions using a numerical protocol, termed "athermal quasistatic random displacement," and find that these mean-field predictions are surprisingly accurate in low dimensions. We identify a general class of perturbations that smoothly interpolates between the uncorrelated localized forces that occur in the high-persistence limit of dense active matter and system-spanning correlated displacements that occur under applied shear. These results suggest a universal framework for predicting flow, deformation, and failure in active and sheared disordered materials.
近年来,人们注意到密集活性物质和受剪无定形固体在力学性能上的相似性,但并没有对其潜在机制进行严格的考察。我们开发了一个平均场模型,该模型预测在无穷维度上,它们的临界行为(由其雪崩统计数据来衡量)应该是等效的,只是在一个依赖于施加场的相关长度的标度因子上有所不同。我们在二维中使用一种被称为“非平衡准静态随机位移”的数值方案来检验这些预测,并发现这些平均场预测在低维度上惊人地准确。我们确定了一类普遍的扰动,它可以平滑地在密集活性物质的高持续极限中出现的无关联局部力和在施加剪切下出现的跨越系统的关联位移之间进行插值。这些结果为预测活性和受剪无序材料中的流动、变形和失效提供了一个通用框架。