Calibration of the contact parameters for soybean-bonded particle model based on DEM

Abstract

To retrieve the simulation contact parameters of the soybean-bonded particle for an effective gas-solid two-phase flow coupling simulation analysis of the working procedure of the pneumatic seed-metering device, the angle of repose (AoR) and angle of stacking (AoS) from the physical seed-piling test were captured as the evaluation indexes. The Plackett-Burman test and the steepest ascent test were ratified to simplify the simulation analysis of the soybean-bonded particles, screening out the crucial influenced factors and centroids. The Box-Behnken response surface test was then implemented to identify the desired saliency factor values, and the universality of the calibrated contact parameters for soybean-bonded particles synthesized with varying fraction particle sizes was eventually confirmed. The results revealed that the effect of the static friction coefficient of soybean-plexiglass (µp−g) on AoR was exceedingly significant, and that of the static and rolling friction coefficients of soybean-soybean (µp−p & Cp−p) was generally prominent. While it was abundantly clear that both µp−p and Cp−p supremely affected AoS. The optimal values determined by the Box-Behnken response surface test yielded ideal values of 0.0678 for µp−p, 0.2453 for µp−g, and 0.0079 for Cp−p, culminating in an AoR of 28.32° and AoS of 28.76°, respectively. Based on the derived optimal simulation contact parameters, the maximal error between the simulated and measured values of AoR and AoS of soybean-bonded particles constructed with various fraction particle sizes was estimated to be 1.59%, implying that the calibrated contact parameters have a superior generality. The insights of this investigation can be effectively applied to the coupled simulation analysis of the pneumatic soybean seed-metering device’s operations, as well as a reference for other researchers to erect particle models for DEM simulation using the bonded particle method.