Simulation Analysis of Dynamic Behavior of Lander Footpad Impact on Lunar Regolith

It is important to study the interaction between lander footpad and lunar regolith for landing stability, safety and landing mechanism design. In this paper, a dynamic mechanical model of lunar regolith impacted by footpads with angle is built, and the dynamic changes of lunar soil under 0°、8°、15°、22° impact angle and 1 m/s, 2 m/s and 4 m/s impact velocity are analyzed by Discrete Element Method (DEM). It is concluded that the maximum impact force is 5080.6 N when the impact velocity is 4 m/s and the impact angle is 0°, and the impact angle was larger; the impact force is smaller when the vertical displacement is the same. In addition, the bigger the angle of footpad impact on lunar soil, the smaller the compaction effect on lunar soil. The change of porosity before and after 22° is only 26.5 %. When the impact angle is fixed, the higher the velocity, the more compact the lunar soil is, and the greater degree of compaction. When the impact velocity is 4 m/s, the change of porosity before and after the impact is 78.1%. The research has certain reference significance for the design of landing mechanism and landing control.