撞击采样是适用于小行星表面微重力环境的采样方式，目前已成功应用于Hayabusa 1和Hayabusa 2小行星探测任务。文章基于国产高性能离散元软件MatDEM，建立小行星微重力撞击采样模型，探索初始撞击速度和弹体形状对撞击后风化层内部特征和溅射颗粒的影响。结果表明，增加初始撞击速度能够增大风化层相同区域内部应力和密实度，提高溅射颗粒数量和来自风化层深部的颗粒数量。在风化层相同区域，锥头弹体能够产生最大的应力峰值，平头弹体产生的应力峰值最小。圆形和平头弹体产生的溅射颗粒数量最多，且具有最好的深部采样能力。锥头弹体产生的溅射颗粒数量最少，深部采样能力最弱。结论有助于理解撞击过程内部机理，为深空探测中的撞击采样方案设计提供参考。

Impact sampling is a sampling method applicable to the microgravity environment on the surface of asteroids and has been successfully applied to the Hayabusa 1 and Hayabusa 2 asteroid exploration missions. In this paper, an asteroid microgravity
impact sampling model is developed based on the domestic high-performance discrete element software MatDEM. The effects of initial impact velocity and projectile shape on the interior regolith features and ejecta after impact are investigated. The results show that increasing initial impact velocity can increase the stress and dense degree inside the same region of the regolith, and increase the number of ejecta particles and the number of ejecta particles from the deep part of the regolith. Within the same area of the regolith, the cone-headed projectile produces the highest stress peaks and the flat-headed projectile produces the lowest stress peaks. Round and flat-headed projectiles produce the highest number of ejecta particles and have the best deep sampling capability. Cone-headed projectile produces the lowest number of ejecta particles and has the weakest deep sampling capability. The conclusions help to understand the internal mechanism of the impact process and provide a reference for the design of impact sampling schemes in deep space exploration.