Calibration of corn kernel simulation parameters during harvest and evaluation of its adaptability

To gain the corn kernel’s bonded particle model and the optimal bonding parameters during harvest for later constructing the discrete meta-model of the integral corn ear, that may be applied for threshing simulation and analysis. Taking the ventral and lateral compressive destructive forces of the large flat kernel as evaluation indexes, the constructed large flat kernel bonded particle model was put through simulated compression tests by introducing the Plackett–Burman and steepest ascent tests to screen out the factors and their centroids with significant effects on the bonding force of corn kernels. The Box-Behnken response surface test was conducted to identify the optimal relevance factor values. The results revealed that the effect of bonded disk radius (R_B) on the large flat kernel’s ventral compressive destructive force was extremely significant, and that of shear stiffness per unit area (k_s) was generally significant. Each saliency variable had an impact on the large flat kernel’s lateral compressive destructive force, in descending order: R_B, k_s, normal stiffness per unit area (k_n), and shear modulus (G_p). The response surface test revealed that the preferred materiality factors were 2.935 × 10⁸ Pa for G_p, 4.069 × 10⁷ N/m³ for k_n, 3.147 × 10⁷ N/m³ for k_s, and 1.036 mm for R_B. On this occasion, the large flat kernel’s simulated ventral and lateral compressive destructive forces were 325.16 N and 114.94 N, with an error of 0.40% and 0.85% from the measured values. A comparison of particle morphologies during simulated and actual compression revealed that the large flat kernel’s ventral and lateral compression states were highly consistent. Simulations of large spherical kernel’s compression with the optimal parameters comprehensively verified the accuracy of the corn kernel bonded particle model constructed, as well as the calibrated simulation input parameters. The investigations of this study could provide a reliable theoretical foundation for the later construction of corn ear DEM models to simulate the threshing process or research into the crushing problem of corn kernels.