The parameters of the discrete element simulation model for rice field soils serve as valuable data references for investigating the dynamic characteristics of the walking wheel of high-speed precision seeding machinery in paddy fields. The research specifically targets clay loam soil from a paddy field in South China. Calibration of essential soil parameters was achieved using EDEM_2022 software (and subsequent versions) discrete element simulation software, employing the Edinburgh Elasto-Plastic Adhesion (EEPA) nonlinear elastic-plastic contact model. The tillage layer and plough sub-base layer underwent calibration through slump and uniaxial compression tests, respectively. Influential contact parameters affecting slump and axial pressure were identified through a Plackett–Burman test. The optimal contact parameter combinations for the discrete element model of the tillage layer and plough sub-base layer were determined via a quadratic rotational orthogonal test. The accuracy of the discrete element simulation model’s parameters for paddy field soils was further validated through a comparative analysis of the simulation test’s cone penetration and the field soil trench test. Results indicate that the Coefficient of Restitution, surface energy, Contact Plasticity Ratio, and Tensile Exp significantly influence slump (p < 0.05). Additionally, the Coefficient of Restitution, Contact Plasticity Ratio, coefficient of rolling friction, and Tangential Stiff Multiplier significantly impact axial pressure (p < 0.05). Optimal contact parameters for the plough layer were achieved with a particle recovery coefficient of 0.49, a surface energy of 18.52 J/m², a plastic deformation ratio of 0.45, and a tensile strength of 3.74. For the plough subsoil layer, optimal contact parameters were a particle recovery coefficient of 0.47, a coefficient of interparticle kinetic friction of 0.32, a plastic deformation ratio of 0.49, and a tangential stiffness factor of 0.31. Results from the cone penetration test reveal no significant disparity in compactness between the actual experiment and the simulation test. The calibrated discrete element model’s contact parameters have been verified as accurate and reliable. The findings of this study offer valuable data references for understanding the dynamic characteristics of the walking wheel of the entire machinery in high-speed precision seeding in paddy fields.

This study aims to analyze the fatigue life of a PTO (power take-off) gearbox used in a paddy field power chassis. The analysis considers factors such as stress concentration, dimensions, surface quality, and load characteristics affecting fatigue life. A finite element simulation was conducted using the Ansys 2022 software to identify the critical point of the PTO shell. The modified nominal stress fatigue analysis method, incorporating a stress adjustment coefficient, was employed to derive the modified S-N curve. Combined with the measured load data of the PTO bench operation, the load data and the 3D model of the PTO shell were imported into the fatigue analysis software n-code to analyze the fatigue life of the PTO gearbox of a paddy field power chassis and compare it with the prediction results from the traditional stress field strength method. The findings indicate that the optimized stress adjustment coefficient method predicts a fatigue life (31,699 h) closer to the actual operational life (20,000 h) compared to the traditional method (39,151 h). This research contributes to the advancement of the analytical techniques for predicting fatigue life in critical components of agricultural machinery.