Soil Modeling for Virtual Design and Performance Analysis of Mobility Systems for Off-Road Industry

Low-ground pressure (LGP) tires that exhibit higher flexibility than conventional standard radial tires are recently introduced for agricultural machine systems. The LGP tires carry a 20% to 40% larger vertical load than the conventional standard radial tires and appear to create a larger contact area on soft soils, potentially reducing soil compaction and improving traction and crop yield potential. Due to the complex soil-to-tire system between deformable soil and flexible tire elements, it has been challenging to fully leverage the dynamic systems modelling and computer-aided engineering (CAE) solutions to accelerate the virtual design and product validation of off-road vehicle mobility systems for developing energy-efficient traction at reduced soil compaction. Methods that deploy similitude scaling laws of soil-to-tire contact interface and developing soil models for high-fidelity computational methods such as the Discrete Element Method (DEM) for predicting 3D contact tire-soil interaction, traction forces, and soil compaction will be presented. The relationship between Bekker-Reece soil modeling techniques and DEM soil material properties was established and applied for predicting motion resistance ratio and rut depth at low and high tire inflation pressures. The predicted MRR at two tire inflation pressure settings were to single-tire test data at Soil Machine Dynamics Laboratory (SDML). 

Presented as part of the virtual ATCx DEM in November 2022.
Speaker: Prof. Mehari Tekeste, Associate Professor, Agricultural and Biosystems Engineering, Iowa State University
Duration: 30 minutes