DEM Modelling of Elastic Adhesive Particles with Application to Lunar Soil

This paper presents the study of the influence of interparticle attractive forces on the stress-strain behaviour of a synthetic material made of elastic adhesive particles attributed with material properties typical of lunar soil. The aim is to address fundamental issues concerning the visible cohesion of lunar soil if compared to terrestrial materials of similar gradation. A micro-mechanical approach by means of the Discrete Element Method (DEM) is utilised to facilitate the reproduction of surface energy effects at the particulate level. Conventional triaxial compression tests are simulated for very dense samples and a wide range of confining pressures, up to 1kPa, typical of the lunar environment. Results show the influence of adhesion at the macroscopic level in terms of friction angle as well as cohesion. Physical explanations of these complex phenomena are advanced, and limitations of the current DEM model are highlighted.