Finite Element Analysis on Interaction between Lunar Regolith and Cutter

The rotary shear failure mainly occurs when coring bits penetrate lunar soil surface or subsurface. In order to reduce the cutting power consumption of coring bit, and considering the coupling effect of weight on bit (WOB) and rotation, a rotary shear mechanics model was developed based on the traditional plane cutting theory in this paper. Using transient dynamic contact analysis module of Ansys, the lunar soil cutting process has been simulated and the stress and strain effect of surrounding soil along with cutter size changing analyzed. The results indicate that the maximum Von Mises stress and strain of the soil decreased and capacity of cutting soil reduced, while the distance between cutter and bit axis increasing and the cutter positive rake angle decreasing. Cutter width is less impact on cutting ability. The simulation results are virtually in accordance with the theoretical, which can guide optimization design of sampling bits.