Research on the impact of a drill bit on the original state of artificial lunar soil using DEM simulation

For a better original state and scientific value of lunar soil samples, research on the impact of drill bits on the perturbation rate based on DEM was carried out. A simulated model of lunar soil was established based on the linear adhesion contact model. The parameters of the model were determined by matching between the mechanics and discrete elements. The evaluation criteria of the original states of the lunar soil samples were built on the basis of actual project needs. Based on this, some simulations for the drilling and sampling of lunar soil with different drill bits were carried out. The impact of drill bit parameters, such as internal diameter, cutting angle and height of bottom-out blade on the perturbation rate, was studied. It is shown by the results that the perturbation rate decreases with both the internal diameter and the height of the bottom-out blade, and there is a minimum value with cutting angle. For the best perturbation rate of lunar soil samples under the constraint conditions of the project, the internal diameter should be 18 mm, cutting angle should be 90°, and height of bottom-out blade should be 5 mm.