变比例与CAO粗粒化方法在石英砂震荡压实模拟中的对比研究

Comparative Study on Variable-Ratio and CAO Coarse-Graining Methods in the Simulation of Vibratory Compaction of Quartz Sand

摘要: 本研究针对离散元(DEM)模拟中颗粒规模庞大导致的计算效率难题，以及恒定绝对重叠(CAO)粗粒化模型统一粗粒比缩放引发的级配失衡、模拟失真等问题，将变比例广义粗粒化模型与CAO粗粒化模型应用于石英砂震荡压实模拟，以原始级配模拟结果为参照，从颗粒堆形态、颗粒分布等维度展开对比验证。研究中设置不同粗粒比工况，系统分析两种模型的模拟精度与适用边界。结果表明，变比例粗粒化模型通过差异化粗粒比分配，有效规避了级配差距扩大问题，在不同粗粒比条件下均能精准复现原始级配的压实形态与颗粒分布规律，具有更宽的放大边界与更强的稳定性，验证了该模型在震荡压实工况下的适用性；CAO模型则适用于窄粗粒比、小粒径范围场景。该研究为大规模颗粒震荡压实模拟提供了高效可靠的粗粒化解决方案，对提升工程模拟计算效率与精度具有重要实践意义。

Abstract: Aiming at the problem of low computational efficiency caused by the large particle scale in Discrete Element Method (DEM) simulations, as well as issues such as gradation imbalance and simulation distortion induced by the uniform coarse-grain ratio scaling of the Constant Absolute Overlap (CAO) coarse-graining model, this study applies the variable-ratio generalized coarse-graining model and the CAO coarse-graining model to the simulation of vibratory compaction of quartz sand. With the simulation results of the original gradation as a reference, comparative verification is conducted from dimensions including particle pile morphology and particle distribution. In the study, different coarse-grain ratio working conditions are set up to systematically analyze the simulation accuracy and applicable boundaries of the two models. The results show that the variable-ratio coarse-graining model effectively avoids the problem of expanded gradation gap through differentiated coarse-grain ratio allocation. It can accurately reproduce the compaction morphology and particle distribution law of the original gradation under different coarse-grain ratio conditions, and has a wider scaling boundary and stronger stability, which verifies the applicability of this model under vibratory compaction conditions. In contrast, the CAO model is only suitable for scenarios with narrow coarse-grain ratios and small particle size ranges. This study provides an efficient and reliable coarse-graining solution for large-scale particle vibratory compaction simulations, and holds important practical significance for improving the computational efficiency and accuracy of engineering simulations.