Terramechanics Modeling of Soil-Wheel Interactions at the Lunar Poles

The proposed terramechanics modeling software presentsnbsp;novel methods to simulate irregular agglutinate shapes in lunar soil and evaluate their interaction with wheeled rovers on the lunar surface. The method combines automated agglutinate generation in a Discrete Element Method (DEM) numerical framework to produce irregular grain shapes composed of bonded particles. Additional factors are introduced in the model to study soil mechanics properties relevant to ISRU and exploration missions targeted at the lunar poles including terrain generation with reduced soil compaction.Unlike previous lunar DEM terramechanics models which incorporate both individual particles to represent agglutinates, the proposednbsp;software allows the interlocking of irregular agglutinate shapes which act to increase angle of repose, shear strength, and abrasivenessnbsp;of the soil.The product of the Phase I project will include automated generation of irregular grain shapes in DEM, coupling of DEM with the Finite Element Methodnbsp;to simulate a wheel and deeper soil layers, and terrain generation routines to allow for variable compaction within the DEM soil layers. These efforts will lead to standalone terramechanics modeling software in Phase II whose mechanical response will be calibrated to results obtained in laboratory experiments.