Abstract:  In order to study the interaction law between soil and transplanting soil touching parts in hilly areas where fungi are planted and obtain the simulation parameters, the Hertz—Mindlin with JKR contact model was used to determine the discrete element parameters of specific soil‑transplanting contact parts with 12%±1% and 20%±1% moisture content. The physical test of soil accumulation angle and the physical test of earth ball slope rolling were carried out. The surface energy, recovery coefficient, dynamic friction coefficient and static friction coefficient between soil particles, soil and transplanting soil touching parts were taken as the calibration objects. The combined rotating center test was designed, and the simulated soil accumulation angle and the rolling distance of the earth ball on 65Mn were taken as the response values. Box—Behnken was used for regression analysis of the test data. With the measured soil accumulation angle and earth ball rolling distance as optimization objectives, the static friction coefficient between soil and soil contact material (65Mn) under two typical water contents as constraint conditions, the discrete element parameters between soil and soil and transplanting soil contact parts of two typical water contents were obtained as follows: When the water content was 12%±1% and 20%±1%, the surface energy, recovery coefficient, dynamic friction coefficient and static friction coefficient among soil particles were 11.042 J/m2 and 11.851 J/m2, 0.412 and 0.574, 0.093 and 0.129, 0.994 and 1.009, respectively. Surface energy, recovery coefficient and dynamic friction coefficient of soil and earth‑touching parts were 5.046 J/m2, 8.026 J/m2, 0.362, 0.388 and 0.066, 0.07. In order to verify the accuracy of the optimized discrete element parameters, verification tests were carried out and the results were as follows: the relative errors of the simulation and physical accumulation Angle of the two typical soil moisture contents were 0.96% and 0.95%, and the relative errors of the simulation and physical rolling test were 0.52% and 1%. The results show that the optimized and calibrated soil model parameters can simulate the real soil model of fungus in this area, and provide an important theoretical basis for the design and optimization of key components of fungus transplanter.

Key words: moisture content, fungus, soil, earth?touching materials, discrete element, parameter calibration

摘要： 为探究种植菌草的丘陵地区土壤间、土壤与移栽触土部件间相互作用的规律并获取其仿真参数，运用Hertz—Mindlin with JKR接触模型对特定的12%±1%和20%±1%的含水率土壤—移栽触土部件进行离散元参数标定。开展土壤堆积角物理试验、土球斜面滚动物理试验。以土壤颗粒间、土壤与移栽触土部件间的表面能、恢复系数、动摩擦系数、静摩擦系数为标定对象，设计旋转中心组合试验并以仿真的土壤堆积角、土球在65Mn板上滚动距离为响应值，采用Box—Behnken对试验数据回归分析，以实测的土壤堆积角、土球滚动距离为优化目标，采用两种典型含水率下土壤与触土材料(65Mn)的静摩擦系数为约束条件，得到两种典型含水率的土壤间、土壤与移栽触土部件的离散元参数：含水率分别为12%±1%、20%±1%时，土壤颗粒间表面能、恢复系数、动摩擦系数、静摩擦系数为11.042 J/m2和11.851 J/m2、0.412和0.574、0.093和0.129、0.994和1.009；土壤与触土部件表面能、恢复系数、动摩擦系数为5.046 J/m2、8.026 J/m2，0.362、0.388和0.066、0.07。为验证优化后离散元参数的准确性，开展验证试验得：两种典型含水率土壤仿真、物理堆积角相对误差为0.96%、0.95%，仿真、物理滚动试验相对误差为0.52%、1%。结果表明，优化标定后的土壤模型参数能够仿真该地区真实的菌草土壤模型，可为菌草移栽械关键部件的设计与优化提供重要理论依据。

关键词: 含水率, 菌草, 土壤, 触土材料, 离散元, 参数标定