Calibration of contact parameters of fresh-eating jujube based on discrete element method: Yuancui jujube in brittle ripe stage

Abstract

In this study, the discrete element model of YCJ particles was established using reverse engineering reconstruction technology and EDEM software, and physical and virtual simulation experiments were conducted to calibrate the contact parameters. In addition, intrinsic parameters and contact parameters of YCJ during the brittle ripening period were measured directly. The heap angle was obtained through heap stacking experiments using the box extraction method, and MATLAB and Origin were utilized to obtain the heap angle. Factors and their ranges significantly affecting the heap angle were selected through Plackett-Burman experiments and steepest ascent experiments using the heap angle as the evaluation index. The physical heap angle of YCJ particles was 17.45°. The optimal combination of static and dynamic friction coefficients between YCJ particles was determined to be 0.395 and 0.446 through variance analysis and optimization calculations of the response surface optimization experiment. Using the optimal parameter combination for simulated heap stacking experiments, a simulated heap angle of 17.3° was measured, with an error of 0.86% compared to the physical heap angle. The results of physical grading and simulated grading experiments for YCJ particles were validated, and the accuracy error under the same operating conditions was 3.28%, with the particle motion state being basically consistent in physical and simulated experiments. The research results indicate that the particle model of YCJ and the calibrated discrete element simulation parameters are reliable, providing a reference for the calibration of contact parameters for fresh-eating jujubes.

Keywords

• Yuancui jujube
• discrete element method
• response surface method
• stacking angle
• contact parameters