Mechanical Properties and Pore Size Distribution in Athermal Shear-Strained Porous Glasses
Mechanical Properties and Pore Size Distribution in Athermal Shear-Strained Porous Glasses
复制标题
无热剪切应变多孔玻璃的机械性能和孔径分布
DOI：
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发表时间：
2021
期刊：
影响因子：
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通讯作者：
B. Gupta
中科院分区：
文献类型：
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作者：
S. Niyogi;B. Gupta
本文研究了多孔玻璃在非热准静态剪切作用下的力学性能和孔隙结构的三维分子动力学模型。玻璃样品由高温熔融状态通过快速热淬火制备。孔隙结构是通过固气分离形成的。静态样品的孔隙形貌变化范围广泛，从互连的孔隙网络到随机分布的致密孔隙，取决于材料密度。我们发现剪切模量在很大程度上取决于密度和孔隙率。在机械载荷作用下，孔隙结构重新排列，体现在孔径分布函数上。结果表明，随着应变的增大，孔隙分布逐渐变宽，相邻孔隙聚并形成较大的孔隙。我们还提出了孔径分布函数的通用标度律，为未变形情况下的高多孔材料提供了良好的数据崩塌。从数据缩放我们确定了一个临界密度，可以归因于从多孔型到块状型材料的过渡点。分析了有限变形条件下标度律的有效性。
In this paper we study the mechanical properties and pore structure in a three-dimensional molecular dynamics model of porous glass under athermal quasistatic shear. The vitreous samples are prepared by rapid thermal quench from a high temperature molten state. The pore structures form via solid-gas phase separation. The quiescent samples exhibit a wide range of pore topography, from inter-connected pore network to randomly distributed compact pores depending on the material density. We find the shear modulus strongly depends on the density and porosity. Under mechanical loading, the pore structure rearranges which is reflected in the pore size distribution function. Our results show that with increase in strain the distribution widens as the adjacent pores coalesce and form larger pores. We also propose a universal scaling law for the pore size distribution function which offers excellent data collapse for highly porous materials in the undeformed case. From the data scaling we identify a critical density which can be attributed to the transition point from a porous-type to bulk-type material. The validity of the scaling law under finite deformation is also analyzed.