Investigation on tillage resistance and soil disturbance in wet adhesive soil using discrete element method with three-layer soil-plough coupling model

Abstract

To reveal the interaction between plough and wet adhesive soil, it's essential to establish an accurate coupling model of the soil-plough system. Traditional Edinburgh elasto-plastic adhesive contact model neglects the adhesion effect when two interactive particles are separated, leading to lower simulation accuracy. Here, an improved contact model of wet adhesive soil by introducing the adhesive force is proposed. Then a novel discrete element model of a three-layer soil-plough coupling system is established, where the liquid bridge force and the adhesion effect are considered. Furthermore, the corresponding soil bin tests are also conducted to demonstrate the effectiveness of the proposed model. Finally, the effect of soil adhesion, ploughing speeds and ploughing depths on the tillage resistance and soil disturbance is analyzed. Results show that the prediction accuracy of the proposed model increases by about 7%, moreover, the soil disturbed area decreases, while the tillage resistance increases with increasing soil adhesion.