Abstract:

：Drilling is an important method which has always been used to acquire lunar rock samples. The stability of drilling load is considered as a key factor for sampling mission. Drilling load is mainly affected by rock drillability which is determined by the rock properties. To acquire drilling load variations, relations among drilling load, drilling parameters and rock properties ought to be analysed by drilling tests in laboratory. Therefor, the marble has been selected as lunar rock simulant based on drillability test. A lunar rock simulant cutting model based on particle flow code 2 dimensions (PFC^2D) has been established aiming at acquiring rock cutting force with small cutting depth during drilling process. The microparameters of PFC^2D model have been determined by Plackett-Burman (PB) design and central composite design (CCD) method. The consistent trend between the simulation and test with different small cutting depths is obtained after the cutting simulations and validation tests. A method for establishing discrete element cutting model of lunar rock simulant can be acquired through the research. It provides the basis for analysing the relations between drill bit configurations and drilling load.

Key words: cutting characteristics, experiment design, PFC microparameters, lunar rock simulant