Numerical Simulation of Soil-Tool Interaction by Discrete Element Method.

Discrete Element Method (DEM) was used to simulate the soil-tool interaction. The model is based on the action of normal, shear, cohesion and friction forces into the cohesive granular medium, calculated as a function of micro-mechanical properties. Macro-mechanical properties of soil-soil and soil-metal were used to determining the micro parameters on the model. In order simulate the tillage operations a soil virtual block was generated in hexagonal compacted array using 45 000 spherical particles forming a cohesive block. A soil-bin installation was conditioned to measuring the draft force in hard-dry and soft-wet soil condition to compare the results with simulation tests. The comparison showed a small under predicted behavior of the model for soft-wet soil; however the results become more accurate toward hard-dry soil conditions. The density changes during simulations and pressures distributions below the tillage tool path is showed, given a dynamic representation of soil internal tension and loosening after tillage operation. [ABSTRACT FROM AUTHOR]