基于离散元法的旋埋刀辊功率分配特性研究

旋埋刀辊作业功率是研究旋埋机理、优化刀辊结构的重要指标，研究旋埋刀辊各部件间功率分配特性可分析旋埋刀辊作业功率组成。通过土槽试验对离散元法仿真的土壤颗粒模型输入参数进行标定，对比不同接触模型在旋埋刀辊作业过程仿真中效果，并对不同工作条件下旋埋刀辊的功率分配特性进行单因素试验。结果表明：Hertz- Mindlin接触模型和Hertz-Mindlin with Bonding接触模型中对刀辊扭矩较为敏感的输入参数为土壤-土壤滚动摩擦系数和粘结刚度，验证试验显示上述输入参数标定的平均误差小于6.5%；对比两种接触模型的仿真效果，Hertz-Mindlin with Bonding接触模型因引入额外粘结力，与实测值平均误差仅为0.7%，更适合对黏土进行仿真；旋埋刀辊作业功率超过一半来自螺旋横刀，不同工作条件下螺旋横刀功率均占刀辊总功率60%左右，且受前进速度、刀辊转速和耕深影响更大；由旋埋刀辊功率分配特性可知，螺旋横刀对刀辊总功率影响较大，应作为旋埋刀辊减阻降耗研究的重点。

Study on the characteristic of power distribution of rotary tillage by discrete element method

The power of rotary blade roller was critical index on the mechanism study and structure optimization. In order to study the characteristic of power distribution of rotary blade roller, the working process was simulated by DEM, and the input parameters were calibrated based on the soil bin experiment. The contact model was compared, and the effect of working condition on the characteristic of power distribution of rotary blade roller was investigated. The results indicated that the rolling friction coefficient between soil and soil and the bonding stiffness were sensitive to the total torque in Hertz-Mindlin contact model and Hertz-Mindlin with Bonding contact model, and the errors of calibration by these parameters were less than 6.5%. Compared the performance of these two contact models, Hertz-Mindlin with Bonding contact model was more suitable for the cohesive soil simulation as it introduced an extra bonding force. The average error was less than 0.7%. The percentages of the helical blade power on the total power was about 60% on different working conditions, and the helical blade power was more sensitive on the working conditions. Therefore, the helical blade should be an important optimized component for the improvement for a rotary blade roller.