农业机械学报2025，Vol.56Issue(7)：116-127,12.DOI:10.6041/j.issn.1000-1298.2025.07.010
面向切割过程仿真的小麦茎秆模型参数标定与试验验证
Parameter Calibration and Experimental Validation of Wheat Straw Model for Cutting Process Simulation
摘要
Abstract
Simulation analysis of wheat plant cutting process based on discrete element method(DEM)is of great significance for the optimization of cutting parts of wheat harvesting machinery,while accurate measurement and calibration of mechanical parameters of wheat plant is an important prerequisite for simulation.Firstly,a wheat straw model based on the Hertz-Mindlin with Bonding model was established in the self-developed AgriDEM software.Then a single pendulum cutting test device was built and dynamic cutting test was carried out to investigate the influence of straw-related physical properties and cutting parameters on the straw-cutting force.At the same time,a dynamic straw-cutting simulation was carried out based on the AgriDEM software.Comparing the simulation results with the actual test,the results showed that the simulation error of straw-cutting forces was increased with the increase of cutting speed when using quasi-static bonding parameters for dynamic cutting simulation.To reduce the simulation error at different cutting speeds,two calibration methods for the bonding parameters of wheat straws were proposed.The first method was a multi-variable central combination optimization calibration method with stiffness coefficient and critical stress as test factors,which obtained the optimized values of the normal stiffness coefficient,tangential stiffness coefficient,critical normal stress,and critical tangential stress for a cutting speed of 1 m/s,respectively,as 2.82 × 1011 N/m3,1.32 × 1011 N/m3,9.50 × 106 Pa and 6.46 × 106 Pa,respectively.The second method was a single-variable calibration method with the bonding radius scaling factor,and the optimized values of the bonding radius scaling factor were obtained as 0.997,1.106,1.163,1.213,1.323 and 1.439 for the pendulum-cutting speeds of 0.5 m/s,1 m/s,1.5 m/s,2 m/s,2.5 m/s,3 m/s,and a fitting equation between the cutting speed and the calibration value of the bonding radius scaling factor was obtained.Finally,by comparing the reciprocating cutting test with simulation at cutting speed of 1 m/s,it was found that using the first calibration method with stiffness coefficient and critical stress,the simulation error of the straw cut-off force was reduced from 22.55％to 9.13％.Using the second calibration method,when the bonding radius scaling factor were 1.068,the simulation error of the straw cut-off force was reduced from 22.55％to 6.58％.This preliminary demonstrated that the two bonding parameter calibration methods proposed can effectively reduce the simulation error of straw-cut-off force,and the use of calibration value of the bonding radius scaling factor corresponded to the middle value of the effective cutting speed to simulate the reciprocating cutting operation was the most accurate and feasible method.The research result can provide a reference for the simulation of wheat cutting operation process and the optimized design of key cutting components.关键词
小麦茎秆/离散元法/AgriDEM软件/动态切割/参数标定Key words
wheat straw/discrete element method/AgriDEM software/dynamic cutting/parameters calibration分类
农业科技引用本文复制引用
孙凯,于建群,赵瑾汶,孙永昌,于亚军,梁留锁,王扬..面向切割过程仿真的小麦茎秆模型参数标定与试验验证[J].农业机械学报,2025,56(7):116-127,12.基金项目
国家自然科学基金重点项目(52130001) （52130001）
