# 0448 / Lunar rover discrete element method study and calibration Title: Lunar rover discrete element method study and calibration Authors: James Hurrell, Keisuke Takehana, Kentaro Uno, and Kazuya Yoshida Abstract: *Context.* The Discrete Element Method (DEM) is a high-fidelity simulation tool to study the interaction of granular material. The single-wheel interaction of a lunar rover wheel with Toyoura sand is studied. Traditionally Toyoura sand is considered cohesionless but is measured to have a cohesion similar to Lunar soil. Aims. Develop a well-calibrated DEM wheel-soil simulation with and without cohesion for an equivalent angle of repose (AoR). \ \&#xNAN;*Methods.* 3D DEM single-wheel simulations are performed for Toyoura sand in Earth conditions. Separate calibration for the simulation parameters uses AoR. The Johnson–Kendall–Roberts (JKR) model is used, allowing for particle cohesion modelling. Simulations are kept homogeneous and use spherical particles. A comparison is made between non-cohesive and cohesive simulations. Traction coefficient, wheel sinkage, wheel trace and soil flow under the wheel are measured. \ \&#xNAN;*Results.* The static friction coefficient, rolling friction coefficient and cohesion have the most significant influence on an AoR. The optimisation model determines ideal parameters for simulating AoR that match experimental values. When applied to single-wheel simulations, there is a slight reduction in traction coefficient for cohesive soil. Differences in sinkage, wheel trace and soil motion are negligible. \ \&#xNAN;*Conclusions.* Alongside the parameter calibration performed, the results of the simulations are considered suitable for traction performance. Improvements can be made with soil depth and consideration of void ratio. For a homogenous soil, cohesion may not be critical to the soil response. Future studies will use direct comparison to experiment, reduced gravity experiments and lunar simulant results to refine the simulations. Order the full paper: ISTVS members: receive three papers per year as part of your membership via the ISTVS Member Portal: --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://2023.istvs.org/submissions/papers/0448.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.