标题： 通过准静态高斯相位包预测二维二氧化硅玻璃中的温度依赖性失效和转变区域 显示英文标题

标题： Predicting temperature-dependent failure and transformation zones in 2D silica glass through quasistatic Gaussian Phase Packets

摘要： 无热准静态（AQS）方法是一种研究无序系统力学行为的有力技术。 然而，其适用性仅限于接近零度的温度，此时热激活不太可能发生。 在本工作中，我们基于一种将原子在准静态条件下描述为相空间中温度依赖的高斯包（GPPs）的公式，将AQS方法扩展到有限温度，因此等价于最小自由能条件。 该框架用于研究温度对在单轴拉伸载荷下接近准静态条件的非晶二维二氧化硅玻璃中塑性变形和断裂起始的影响。 该公式的显著特征是配置空间中每个高斯包的方差的方向依赖性，使该公式成为一种廉价且准确的预测原子尺度重排区域的方法，无论是在未变形状态下，还是随着变形的进行（准确性不断提高）。 该方法还被证明能够准确捕捉无序材料的热膨胀。 此外，将GPP描述与Metropolis抽样相结合，可以预测温度对材料断裂起始的影响，该预测通过应变率低至$10^{4}$s$^{-1}$的分子动力学模拟得到了验证。 因此，所提出的框架为研究有限温度下无序材料的非线性力学以及高效预测无序固体中的局部重排区域提供了一种有价值的技巧，而无需进行昂贵的分子动力学模拟。 显示英文摘要

摘要： The athermal quasistatic (AQS) method is a powerful technique to study the mechanical behavior of disordered systems. However, its applicability is limited to temperatures near zero, where thermal activation is unlikely. In this work, we extend the AQS method to finite temperatures, based on a formulation that describes atoms as temperature-dependent Gaussian packets (GPPs) in phase space under quasistatic conditions, thus equivalent to minimum free energy conditions. This framework is used to study the effect of temperature on the onset of inelasticity and fracture in amorphous two-dimensional silica glass approaching quasistatic conditions under uniaxial tensile loading. An important characteristic of this formulation is the directional dependence of the variance of each Gaussian packet in configuration space, making this formulation an inexpensive and accurate predictor of zones prone to atomic-scale rearrangements, both in the undeformed state and (with increasing accuracy) as the deformation progresses. This method is also shown to accurately capture the thermal expansion of the disordered material. Furthermore, combining the GPP description with Metropolis sampling predicts the effect of temperature on the onset of fracture of the material, which is validated through MD simulations at strain rates as low as $10^{4}$s$^{-1}$. The presented framework therefore provides a valuable technique for studying the nonlinear mechanics of disordered materials at finite temperature and for predicting local rearrangement zones in disordered solids efficiently without the need for expensive MD simulations.