苜蓿现蕾期茎秆离散元模型建立与参数标定  

Establishment of Discrete Element Model and Parameter Calibration of Alfalfa Stem in Budding Stage

作　　者：陈涛 衣淑娟[1] 李衣菲[1] 陶桂香[1] 曲善民[2] 李睿 CHEN Tao;YI Shujuan;LI Yifei;TAO Guixiang;QU Shanmin;LI Rui(College of Engineering,Heilongjiang Bayi Agricultural University,Daqing 163319,China;College of Animal,Heilongjiang Bayi Agricultural University,Daqing 163319,China;College of Mechanical and Vehicle Engineering,Taiyuan University of Technology,Taiyuan 030024,China)

机构地区：[1]黑龙江八一农垦大学工程学院,大庆163319 [2]黑龙江八一农垦大学动物科技学院,大庆163319 [3]太原理工大学机械与运载工程学院,太原030024

出　　处：《农业机械学报》2023年第5期91-100,共10页Transactions of the Chinese Society for Agricultural Machinery

基　　金：国家自然科学基金项目(52275246);黑龙江省科技计划项目(YS20B10)。

摘　　要：针对目前牧草收获、粉碎加工设备输送和切割等机构研究过程中离散元仿真缺乏准确模型的问题,以含水率高、物理力学特性较为复杂的苜蓿现蕾期茎秆为研究对象,借助EDEM仿真软件,分别基于Hertz-Mindlin(no slip)和Hertz-Mindlin with bonding接触模型对物理参数和粘结参数进行标定。以休止角和剪切试验为基础,通过Plackett-Burman试验、Steepest ascent试验和Box-Behnken试验确定了苜蓿茎秆的泊松比、剪切模量、碰撞恢复系数、静摩擦因数、滚动摩擦因数等物理参数和法向接触刚度、切向接触刚度、临界法向应力、临界切向应力、粘结半径等粘结参数。以确定的物理参数进行休止角仿真试验,结果表明,仿真休止角与物理试验休止角相对误差为0.52%;以确定的粘结参数进行剪切仿真试验,结果表明,仿真剪切破坏力与物理试验仿真破坏力相对误差为0.86%,说明所标定的参数能够真实反映苜蓿现蕾期茎秆的物理和力学特性。In view of lack of accurate models for discrete element simulation in the current research and development process of forage harvesting,crushing,processing equipment transportation and cutting,the alfalfa budding stem with high moisture content and complex physical and mechanical characteristics was taken as the research object.With the aid of EDEM simulation software,the physical parameters and bonding parameters were calibrated based on Hertz-Mindlin(no slip)and Hertz-Mindlin with bonding contact models respectively.Based on angle of repose and shear test,physical parameters such as Poisson’s ratio,shear modulus,impact recovery coefficient,static friction coefficient,rolling friction coefficient and bonding parameters such as normal contact stiffness,tangential contact stiffness,critical normal stress,critical tangential stress and bonding radius of alfalfa stem were determined through Plackett-Burman test,the Steepest ascent test and Box-Behnken test.The relative error between the simulated angle of repose and the physical angle of repose was 0.52%.The results showed that the relative error between the simulated shear failure force and the physical test simulation failure force was 0.86%,which indicated that the calibrated parameters can truly reflect the physical and mechanical characteristics of alfalfa stems at the budding stage.It provided a reliable model and parameter calibration method for the discrete element simulation in the research and development process of forage machinery,and also provided a reference for the research and development,optimization design and power matching of the conveying and cutting mechanisms of forage harvesting and crushing processing equipment.

关 键 词：牧草 苜蓿茎秆 休止角 剪切破碎 离散元 参数标定 

分 类 号：S223.2[农业科学—农业机械化工程]