Enhancing Discrete Element Model Accuracy for Lunar Soil: Calibration and Validation of Mesoscopic Parameters

This study introduces a novel discrete element model calibration methodology incorporating particle shape and the van der Waals forces between particles. The effect of mesoscopic parameters on peak stress and failure point are systematically calibrated in the model by triaxial compression stress-strain curves. The results show that six meso-parameters have significant impact on the mechanical response of the model, including effective modulus, rolling friction coefficient, normal-to-shear stiffness ratio, damping coefficient, maximum attractive force and attraction range. The model accurately simulates complex mechanical behavior in both loose, dense lunar soils and soil-tool interaction.

本研究提出一种兼顾颗粒形貌与颗粒间范德华力的离散元模型（discrete element model）校准新方法。本研究借助三轴压缩应力-应变曲线，系统校准了模型内细观参数对峰值应力与破坏点的影响规律。研究结果表明，共有6种细观参数对模型的力学响应具有显著影响，具体包括有效模量、滚动摩擦系数、法向-切向刚度比、阻尼系数、最大吸引力以及吸引作用范围。该模型可精准模拟松散、密实月壤以及土壤与机具间的复杂力学行为。