To investigate the interaction mechanism between agricultural tillage machinery and soil, this study established a precise simulation model by integrating physical and numerical experiments using typical yellow cinnamon soil collected from western Henan Province, China. The discrete element parameters for soils with varying moisture contents were calibrated based on the Hertz–Mindlin (no slip) contact model. Through Plackett–Burman screening, steepest ascent optimization, and Box–Behnken response surface methodology, a predictive model correlating moisture content, parameters, and repose angle was developed, yielding the optimal contact parameter combination: interparticle static friction coefficient (0.6), soil–65Mn static friction coefficient (0.69), and interparticle rolling friction coefficient (0.358). For the Bonding model, orthogonal experiments coupled with NSGA-II multi-objective optimization determined the optimal cohesive parameters targeting maximum load (673.845 N) and displacement (9.765 mm): normal stiffness per unit area (8.8 × 10⁷ N/m³), tangential stiffness per unit area (6.85 × 10⁷ N/m³), critical normal stress (6 × 10⁴ Pa), critical tangential stress (3.15 × 10⁴ Pa), and bonding radius (5.2 mm). Field validation using rotary tillers and power harrows demonstrated less than 6% deviation in soil fragmentation rates between simulations and actual operations, confirming parameter reliability and providing theoretical foundations for constructing soil-tillage machinery interaction models.

A multi-parameter optimization-based design method for soil-mixing blades was proposed to address the issue of excessive straw residue in the seeding layer after maize straw incorporation. A discrete element model simulating the interaction between the soil-mixing blades, soil, and corn straw was established. The key structural parameters included the bending line angle (α), bending angle (β), side angle (δ), tangential edge height (h), and bending radius (r); the straw burial rate (Y₁) and straw percentage in the seeding layer (Y₂) were selected as evaluation indicators. Single-factor experiments determined the significance level (p < 0.05) and the parameter range. A Box–Behnken response surface design, combined with analysis of variance (ANOVA), was employed to elucidate the influence patterns of the structural parameters and their interactions regarding straw burial performance. Multi-objective optimization yielded an optimal parameter combination: α = 55°, β = 100.01°, δ = 130°, h = 40.05 mm, and r = 28.67 mm. The simulation results demonstrated that this configuration achieved a Y₁ of 96.04% and reduced Y₂ to 35.25%. Field validation tests recorded Y₁ and Y₂ values of 96.54% and 34.13%, respectively. This study quantitatively elucidated the relationship between soil-mixing blade parameters and straw spatial distribution, providing a theoretical foundation for optimizing straw incorporation equipment.

This study aimed to address the issues of high tillage resistance and uneven force distribution caused by conventional tine arrangements during the operation of driven harrows. The effects of tine structural parameters and arrangement patterns on operating resistance were systematically investigated through a combination of three-dimensional force analysis and simulation tests. Tine structure parameters were optimized, with tine rake angle, blade inclination angle, inner bending angle, and chamfer angle set as variables, and the mean force on the tine taken as the response value. The following optimal structural parameter combination was obtained via simulation tests: tine rake angle 0°, blade inclination angle 0.014°, inner bending angle 15°, and chamfer angle 10.04°, under which the mean force was determined to be 205.81 N. On this basis, a specific tine arrangement pattern was proposed. Based on single-tine force analysis, a resultant force model for eight groups of tines was established by means of phase angle superposition. With the standard deviation of the resultant force and the average of the maximum force values being adopted as multi-objective responses, the arrangement parameters were optimized. The results showed that when the initial mounting angle was set to 104° and the arrangement angle to 125°, the force standard deviation of the system was 79.48 N, and the average of the maximum force values was 1329.98 N, corresponding to the minimum fluctuation in operating resistance and the most uniform load distribution. This study provides a theoretical basis for the structural design and arrangement optimization of driven harrow tines, which is conducive to improving operational stability and tillage efficiency.