Use of Particulate Mechanics Concept in Characterizing Soil and Crop Residue Interaction in Tillage

ABSTRACT: Discrete Element Method (DEM) can be used to simulate and assess the performance of a conceptualized soil-engaging tool for tillage applications. In the design of a high-performance soil-engaging tool, it is important to study the interactions of materials involved during tillage: soil, crop residues, and tilling tool. This study focused on crop residues and their interaction with soil. Microparameters of crop residues and soil-residue interface were characterized by back-calculating it using DEM simulations of laboratory experiments. Laboratory experiments performed and simulated were ring shear and direct shear test. The DEM contact model used was linear contact model. Sensitivity analyses on the laboratory test models were performed and it revealed that both particle stiffness (k) and friction (µ) were influential for direct shear test while only µ was influential for the ring shear test. Sensitive microparameters were then thoroughly adjusted until the simulation results matched the laboratory test results. Characterized microparameters can be utilized in improving the reliability of soil-tool-residue DEM models used for tillage simulations.