着陆作用下月尘激扬的三维离散元分析

3-D DEM Analysis of Lunar Dust Levitation Characteristics during Landing Progress

基于模拟月尘的细观颗粒形状,采用刚性圆球单元重叠法建立了4种典型不规则模拟月尘颗粒的三维几何模型。根据月尘所处环境和颗粒间接触特性,建立了月尘离散元接触力学模型。通过三轴压缩实验离散元模拟的结果和模拟月尘的实际三轴压缩实验数据的对比,确定模拟月尘颗粒的三维离散元模型参数。采用建立的模型和获得的参数,进行了圆盘模拟体着陆作用下月尘激扬模拟。通过跟踪圆盘模拟体和月尘运动,统计分析了月尘运动特性及其漂浮分布情况,分析着陆速度和颗粒刚度的变化对月尘漂浮的影响。

Based on the particle shape of a simulated lunar dust, four typical types of three-dimensional （3-D） geometric models of irregular particles are built by overlapping rigid spheres units. The discrete element contact mechanics model is built according to the environment and contact characteristics of lunar dust. The discrete element model（DEM） parameters are determined by comparing the data from simulated triaxial tests and actual experiments. By using obtained model parameters, the levitation of lunar dust caused by the landing of a simulated disc body is stud- ied. By tracking the movement of the disc and lunar dust, the motion characteristics and levitating distribution of lunar dust are statistically analyzed. And the influence of the landing speed and the change of the particle stiffness on the levitation of the dust are also discussed.