This paper outlines a framework for using molecular dynamics to simulate the compression of kaolinite saturated at alkaline pH (=8) in a low (1 mM) concentration solution. The particles are modelled as flat (3D) ellipsoids and their interactions are described by a modified form of the Gay-Berne potential, calibrated against DLVO theory. The LAMMPS software was used to generate monodisperse and slightly polydisperse samples, and to simulate isotropic compression to 100 kPa. The influences of sample size and strain rate on the void ratio and the arrangement of particles within the samples were investigated via parametric studies. It is useful to consider the extent to which the system temperature (a measure of the average kinetic energy) is controlled when assessing whether the applied strain rate is appropriate. It is found that the number of particles that can be considered a representative element volume is orders of magnitude larger than the number simulated in earlier studies and that larger number of particles are required in polydisperse samples than in the monodisperse case. A comparison between the results obtained and those of published experimental studies show that the methodology proposed can deliver sensible results for the material considered.

本文概述了使用分子动力学模拟低 (1 mM) 浓度溶液中碱性 pH (=8) 饱和高岭石压缩的框架。粒子被建模为平面 (3D) 椭球，它们的相互作用由 Gay-Berne 势的修改形式描述，根据 DLVO 理论校准。LAMMPS 软件用于生成单分散和轻微多分散样品，并模拟各向同性压缩至 100 kPa。通过参数研究研究了样品尺寸和应变速率对孔隙率和样品内颗粒排列的影响。在评估施加的应变率是否合适时，考虑系统温度（平均动能的量度）的控制程度是有用的。发现可以被视为具有代表性的元素体积的粒子数量比早期研究中模拟的数量大几个数量级，并且多分散样品中需要比单分散情况下更多的颗粒数量。获得的结果与已发表的实验研究的结果之间的比较表明，所提出的方法可以为所考虑的材料提供合理的结果。