基于离散元法的巨菌草开沟器工作过程仿真与结构优化

Stimulation and optimization of Juncao opener structural parameters using discrete element method

针对目前巨菌草种植机开沟器工作耗能大、种床不平整、土壤保墒力差以及种苗发芽率低等问题,应用离散元法开展开沟器触土过程动力学仿真及结构优化.以福建地区土壤为试验样本,选择延迟弹性模型与线性内聚力模型作为土壤颗粒接触模型;确定入土角、入土隙角和斜面角等开沟器关键结构参数,设计三因素五水平的均匀试验,通过EDEM软件建立土壤-开沟器相互作用的三维离散元仿真模型,以最小工作阻力与土壤扰动情况为目标进行仿真试验.结果表明:当开沟器入土角、入土隙角、斜面角分别为45°、3°和60°时,开沟器可产生较小工作阻力,对土壤的扰动量较小,种床质量优良,有利于种苗生长.

Faced with problems such as high working resistance,uneven seedbeds,poor soil moisture conservation and low seed germination rate,discrete element method was applied to optimize the structural parameters for Juncao opener.Soil particle contact model was established on hysteretic spring contact model and linear cohesion model on soil from Fujian Province.Uniform experiment with 3 factors of penetrating angle,clearance angle and chamfered angle was conducted,at 5 levels to optimize the opener structural parameters.To realize a minimum power consumption and soil disturbance,a three-dimensional discrete element simulation model of soil-opener interaction was established by EDEM software.The results indicated that opener with penetrating angle at 45°,clearance angle at 3°and chamfered angle at 60°resulted in a minimum work resistance and soil disturbance,and high-quality seedbed that promoted seedling growth.