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arXiv 0905.0988cond-mat.softcond-mat.dis-nn
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非晶态固体静态结构和平均配位的简单模型

Simple model for the static structure and the mean coordination of amorphous solids

Alessio Zaccone

摘要:

我们提出了一个简单的路线来评估静态结构,在平均协调方面,完全无序固体与球形成分,从ca。55%的体积分数高达随机紧密堆积,在结构不均匀的情况下。根据目前的理解,根据这种理解,非晶态固体中决定结构的相互作用是核心排斥,而较弱的、较长距离的相互作用仅仅是微扰,该模型产生了固体中的平均配位,这是超淬火过程的结果,在超淬火过程中,前体液体快照的瞬时结构被扭曲到与淬火硬-球形液体在体积分数为64%时进入等静压堵塞状态。变形的特征长度约为颗粒直径的3%。外推到较低的体积分数,这是淬火路线,从而导致最空间均匀的状态。因此,该模型可用于定量评估非晶态固体的结构不均匀性程度。当空间不均匀性很小时,对于非常密集的系统,该模型可以用于评估坐标相关的宏观性质(例如弹性模量),如平行工作中所示。

英文摘要:

We propose a simple route to evaluate the static structure, in terms of average coordination, of completely disordered solids with spherical constituents, from ca. 55% volume fraction up to random close packing, in the absence of structural heterogeneities. Based on the current understanding, according to which the structure-determining interaction in amorphous solids is the hard-core repulsion while weaker, longer-range interactions are mere perturbations, the model yields the average coordination in the solid as a result of a hyperquenching process where the instantaneous structure of the precursor liquid snapshot is distorted to the same degree required to quench the hard-sphere liquid into the isostatic jammed state at 64% volume fraction. The characteristic length of distortion turns out to be about 3% of the particle diameter. Extrapolating to lower volume fractions, this is thus the quenching route leading to the most spatially homogeneous states. Thus the model can be usefully employed to quantitatively assess the degree of structural inhomogeneity in amorphous solids. When spatial inhomogeneity is small, as for very dense systems, the model can be used to evaluate coordination-dependent macroscopic properties (e.g. the elastic moduli) as shown in parallel works.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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