DEM simulation of stress transmission under agricultural traffic Part 3: Evaluation with field experiment
In a concurrent paper, we compared a continuum model and a discrete element method (DEM) model in simulating stress transmission in soil under a wheel. Here, those models are evaluated with measurements of vertical normal stress (σz) under the wheels of a tractor-slurry spreader setup. It was found that the variation in the measured σz could be explained by the heterogeneous stress distribution in our structured soil, similar to what is observed in the DEM simulation. Furthermore, comparison of the continuum and DEM model showed that the lack of horizontal forces and dynamic load transfer at the boundary condition in the continuum model lead to a systematic underestimation of the measured σz. Traction and drawbar forces have a significant impact on the stress state under a wheel. The continuum model and its boundary conditions should be modified to include these forces accurately.
Keywords: Soil compaction, Traction, Terramechanics