深松铲不同翼铲安装高度时土壤扰动行为仿真与试验

Discrete Element Simulations and Experiments of Disturbance Behavior as Affected by Mounting Height of Subsoiler's Wing

翼铲的安装高度是带翼深松铲的关键结构参数之一,其对深松土壤扰动行为产生重要影响。综合运用EDEM和室内土槽试验,研究了翼铲安装高度(55、75、95、115、135 mm)对深松土壤扰动行为的影响。结果表明:随着翼铲安装高度增加,耕后犁底层土壤扰动面积先增大后减小,在翼铲安装高度为75 mm时最大,水平耕作阻力逐渐减小,深松铲铲尖和犁底层圆弧段所受水平耕作阻力为深松铲水平耕作阻力的主要来源(90%以上),其随翼铲安装高度增大逐渐减小;翼铲安装高度直接影响耕作时不同深度土壤在不同方向的位移,当翼铲安装高度为75 mm时,深松铲纵向中心位置的各层土壤在耕作方向的最大位移相对较小,其犁底层土壤在竖直方向最大位移相对较大,表层和耕作层土壤在竖直方向最大位移相对较小;翼铲安装高度对土壤扰动效果产生重要影响,且离散元仿真能够准确模拟深松土壤的扰动过程,5个翼铲安装高度下土壤膨松度、土壤扰动系数、土壤碎土系数、土壤纵向堆积角的试验值和仿真值的平均误差分别为11.69%、11.54%、14.20%、9.64%。

The mounting height of the wing is one of the key structural parameters of the winged subsoiler,which greatly affects disturbance behavior of subsoiling.The disturbance behavior and resistance under different heights of the wing(55 mm,75 mm,95 mm,115 mm and 135 mm)were compared and analyzed by the comprehensive use of EDEM and digitized soil-bin test.The results showed that with the increase of mounting height of the wing(MHW),the disturbance area of hardpan layer after subsoiling was increased first and then decreased,and it reached the maximum when MHW was 75 mm;moreover,the horizontal tillage resistance was decreased gradually with the increase of MHW,and the horizontal tillage resistance of the share and arc section in the hardpan layer was the main source of horizontal tillage resistance of subsoiler(more than 90%),which was also decreased gradually with the increase of MHW;MHW directly affected the displacement of different directions of soil at different depths during tillage.When MHW was 75 mm,the maximum displacement in the working direction of soil of each layer in the longitudinal center of the subsoiler was relatively small,the maximum displacement in the vertical direction of the soil in hardpan layer was relatively large,and the maximum displacement in the vertical direction of the top soil and the soil of tillage layer was relatively small;and a proper mounting height of the wing was of great importance to disturbance effectiveness,and the discrete element simulation could accurately simulate the disturbance behavior of subsoiling.The average errors of five mounting heights of the wing of soil bulkiness,soil disturbance coefficient,soil fragmentation parameter and longitudinal accumulation angle of surface soil between simulation and experiment were 11.69%,11.54%,14.20%and 9.64%,respectively.