Modelling vibrational segregation of granular materials in lunar gravity using the discrete element method

Advancing in-situ resource utilisation (ISRU) strategies will be critical for the sustainability of future lunar missions. One of the key operational challenges for ISRU is the development of efficient dry particle size classification methods under reduced gravity conditions. This study investigates the applicability of vibrational segregation, also known as the Brazil Nut Effect (BNE), as a dry segregation mechanism for granular materials in lunar gravity using Discrete Element Method (DEM) simulations calibrated against laboratory experiments under terrestrial conditions. The results confirm that the BNE is not only viable but potentially enhanced in lunar gravity, with simulations showing that lower amplitudes are sufficient to induce segregation, and that segregation quality and speed are enhanced under reduced gravity compared to terrestrial conditions. The study further identifies an optimal amplitude–frequency relationship for maximizing segregation efficiency under lunar conditions, supporting its use as a candidate technology for dry size classification in future lunar ISRU operations. This work contributes to bridging the gap between theoretical granular segregation principles and practical implementation within the constraints of the lunar environment. • Vibrational segregation is effective for dry size classification under lunar gravity. • Reduced gravity enhances segregation quality, enabling operation at low amplitudes. • Calibrated DEM simulations accurately reproduce experimental behaviour. • An inverse amplitude-frequency relationship defines optimal operating conditions.