This paper established an accurate discrete element for ultrasonic vibration-cutter-soil interaction model to study the interaction mechanism between the soil-engaging component and the soil. In order to reduce the interaction between calibration parameters and improve the calibration accuracy, it is proposed that the soil constitutive, contact parameters, and bonding parameters be calibrated by combining the soil repose angle experiment and the soil resistance experiment of ultrasonic vibration cutting. The study adopts the Hertz-Mindlin (no slip) contact model used in EDEM, to explore soil particle interactions. The central composite design is used to achieve systematic investigation. 3-factor 3-level orthogonal design experiment was employed using the coefficient of restitution, the coefficient of static friction, and the coefficient of rolling friction as key test factors and soil’s repose angle as the response index. Based on the Hertz-Mindlin with bonding contact model, Design-Expert 13.0 software was used to design the Plackett-Burman experiment, the steepest ascent, and the Box-Behnken experiment. With the maximum soil cutting resistance in ultrasonic vibration cutting experiment used as the response value, the adhesion parameters were optimized, and the optimal solution combination was obtained as: Normal Stiffness = 4.635 × 10⁶ N/m, Shear Stiffness = 3.401 × 10⁶ N/m, and Bonded Disk Radius = 2.57 mm. The optimal parameter combinations obtained from the calibration experiments were verified in two ways: ultrasonic vibration cutting and non-ultrasonic vibration cutting. The results showed that the errors between the simulation values and the actual values of the two comparative experiments were less than 5%, and the model calibrated for the three parameters can be used to study the drag reduction mechanism of ultrasonic vibration cutting in soil.

To address unstable seed filling and susceptibility to seed damage in air-suction peanut seed-metering devices, a flexible cell-hole seed-metering device comprising a double-layer seed-metering disc, elastic rubber cell-hole inserts, and conical springs was developed. EDEM simulations, bench tests, and field tests were conducted to investigate the effects of cell-hole type, cell-hole height, and seed-metering disc speed. Seed velocity, force, and disturbance transmission characteristics were analyzed in the simulations, while seed-metering performance was evaluated using the miss-seeding, multiple-seeding, and seed-damage indices in the bench tests. The results showed that the single ellipsoid cell-hole type produced greater consistency between the directions of seed motion and cell-hole movement. A cell-hole height of 5 mm provided an effective balance between seed disturbance and damage reduction, while a seed-metering disc speed of 20 r/min improved seed-adsorption stability. In the field tests, the mean miss-seeding, multiple-seeding, and seed-damage indices were 3.75%, 4.54%, and 1.75%, respectively. These findings demonstrate that flexible cell holes can guide seeds to move with the cell holes and promote the stable transmission of localized disturbance throughout the seed mass, thereby providing an effective approach to improving seed-adsorption stability while limiting mechanical damage.