To determine the desirable bonding parameters of the soybean-bonded particle model for accidentally simulating the working process of a pneumatic soybean seed-metering device. Taking the compressive destructive force (F_c,p) derived from the uniaxial compression test of soybean seeds as the evaluation index for the compression simulation tests. The Plackett–Burman and the steepest ascent tests were executed to identify the centroids of the influential factors that substantially affect the bonding force of the soybean-bonded particle model. The optimal values of the significance influencing variables were determined based on the Box–Behnken response surface test. The results indicated that the effect of bonded disk radius (R_B,p) between fraction particles on the F_c,p was extremely significant, and the effects of the restitution coefficient (e_p-steel) and static friction coefficient (μ_p-steel) of soybean-steel, normal stiffness per unit area (k_n,p) and critical normal stress (σ_max,p) were found to be statistically significant. The preferred values identified by Box–Behnken response surface test were 0.520 for e_p-steel, 0.274 for μ_p-steel, 4.082 × 10⁷ N/m³ for k_n,p, 3.517 × 10⁵ Pa for σ_max,p, and 0.982 mm for R_B,p, respectively. The compressive destructive force of soybean seeds was 211.32 N at this point, which was 0.2% less than the measured value of 211.74 N. The results of comparing the grain morphologies during the actual and simulated compressions indicated that the compression states had a superior consistency. It was determined that the DEM simulation input parameters for the soybean-bonded particle model calibrated were proven to be effective and dependable. The investigation presented in this paper can be utilized to effectively analyze the working process of the pneumatic soybean seed-metering devices through coupled simulation. It can also serve as a reference for other researchers to construct a particle model for DEM simulation using the BPM approach.

The optimal discrete element model and bonding parameters that match the structural features of cornstalks during harvest were obtained. Based on the differences in mechanical properties of the stem bark and stem pith in the inter-nodal cornstalk, the biomechanical-specific parameters were measured using the compression, shear, and bending tests. The bonded particle models of stem bark and stem pith were constructed using fraction particles with radii of 1 mm and 1.47 mm, which were further bound to form a bilayer-bonded particle model of the cornstalk. The Plackett–Burman, steepest ascent, and response surface tests were conducted to identify the factors and their optimal values that significantly impacted the stem bark-stem bark, stem pith-stem pith, and stem bark-stem pith bonding parameters. The cornstalk’s shear and bending mechanical properties were assessed to verify the overall characteristic parameters. The findings revealed that the cornstalk model created, and the calibrated bonding parameters, were highly accurate and capable of simulating the shearing and bending behaviors of the real cornstalk. The inter-nodal cornstalk’s bonded particle model created and the identified bonding parameters for the cornstalk could contribute to a theoretical and research basis for the next stage in cornstalk modeling with nodes and other applications.