DEM Investigation on the Collecting Characteristics and Performance Evaluation of Lunar Soil Within a Hollow Drilling Tool

ABSTRACT Lunar soil collection is pivotal for advancing extraterrestrial exploration, enabling in‐situ mineral resource utilization, sustainable lunar base construction, and scientific investigations into lunar geological history. In this study, the collection behavior of lunar soil within a hollow drilling tool was investigated using the Discrete Element Method (DEM) based on the Hertz‐Mindlin contact model. The effects of key parameters of drilling tool in direct contact with the sample, including inner diameter of the drill pipe ( D ), friction coefficient ( μ ), and height of the complement interior the drill bit ( H ) on macroscopic properties (sample mass, coring ratio, uniformity) and microscopic properties (pore size, disturbance) were systematically analyzed. Results demonstrated that increasing D or decreasing μ enhances sample mass and disturbance rate, while reducing H increases sample mass but reduces disturbance rate. Collection law analysis revealed that the sample can be divided into three regions: the new sample region, the radial movement region, and the flow region. Mechanism analysis uncovered that the energy loss caused by collision and friction changes the average velocity of particles relative to the drilling tool, and the horizontal force arch formed between particles hinders the particle motion. The response surface method (RSM) was employed to predict sample mass and disturbance rate, demonstrating high accuracy ( R ² > 0.95). The findings provide valuable insights for optimizing lunar soil sampling tools and offer practical guidance to balance efficiency and sample integrity in extraterrestrial missions.