固沙装备插草圆盘前进速度与阻力关系分析
投稿时间:2019-11-01    点此下载全文
引用本文:李艳洁,寇英涛,张恒宇,刘晋浩.固沙装备插草圆盘前进速度与阻力关系分析[J].中国农业大学学报,2020,25(10):137-146
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作者单位E-mail
李艳洁 北京林业大学 工学院, 北京 100083 liyanjie@bjfu.edu.cn 
寇英涛 北京林业大学 工学院, 北京 100083  
张恒宇 北京林业大学 工学院, 北京 100083  
刘晋浩 北京林业大学 工学院, 北京 100083  
基金项目:国家自然科学基金项目(31971803);中央高校基本科研业务费专项资金资助(2016ZCQ08,2017ZY37)
中文摘要:针对插草圆盘试验中存在偏载而导致的误差问题,采用离散元数值模拟和试验相结合的方法,对机械化铺设草方格过程中纵向插草圆盘在竖直方向插草阻力的影响因素及其影响规律进行研究,对草秆的运动规律进行理论分析,得到了单根草秆被插草圆盘滚动下压至最低位置的时间和相邻两根草秆开始运动时间差的计算公式,圆盘在1个运动周期内所接触的草秆数量,以及草秆在竖直方向的平动速度与圆盘前进速度的定量关系式。利用自行设计的土槽试验装置,进行竖直插草试验,对草秆转动的角速度与角加速度进行标定。利用离散元法建立插草圆盘插草的草秆-沙土三维模型,并仿真插草圆盘滚动插草的过程。仿真结果表明:1)对草秆运动的理论分析结果适用于插草动态过程离散元仿真;2)当圆盘前进速度在4~10 cm/s区间时几乎不会影响竖直方向的稳态插草阻力;3)圆盘竖直方向插草阻力随着草秆铺设密度的增加而增大。本研究揭示了圆盘滚动插草过程中,草杆的运动规律与圆盘前进速度等参数间的定量关系,并在试验标定参数的基础上,得到了圆盘速度、草秆铺设密度对插草阻力的影响规律。
中文关键词:固沙插草  插草圆盘  草方格  离散元法
 
Analysis on the relationship between the blade velocity and resistance of the sand fixing equipment
Abstract:In order to solve the error caused by the bias load in the experiment of planting grass disc, the influencing factors and the regularity of the resistance to the longitudinal grass inserting in the vertical direction during the mechanized straw checkerboards laying are studied by combining discrete element method simulations and experiments. Theoretical analysis of grass stalk movement is conducted. The results show that: A formula is obtained for calculating the difference between the time when a single straw is rolled down by the inserted disc and the starting time of two adjacent straws, and the number of straws that the disc touches in one exercise cycle is calculated and the quantitative relationship between the translational speed of the vertical direction of the straws and the forward speed of the disc is investigated. A self-designed soil test device is used to perform a vertical straw inserting test, and the initial angular velocity and acceleration of the straw rotation are calibrated. A three-dimensional model of straw-sand soil was established by using the discrete element method, and the process of inserting the straw by the disc was simulated. The simulation results showed that: 1)The result of theoretical analysis on straw motion confirmed that the 3D model is suitable for the dynamic process of grass insertion by discrete element simulation; 2)When the disc's forward speed is in the range of 4-10 cm/s, it will hardly affect the steady-state grass insertion resistance in the vertical direction; 3)The resistance of straw insertion in the vertical direction of the disc increases with the increase of the laying density of straws. In conclusion, this study reveals the quantitative relationship between the law of the straw's movement and the forward speed of the disc during the rolling process of disc insertion. Based on the experimental calibration parameters, the effects of disc speed and straw lay density on cutting resistance are obtained through simulation.
keywords:inserting straws  disk blade  straw checkerboards  Discrete Element Method
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