农田残膜机械回收膜土分离模型的建立与仿真试验

Establishment and simulation experiment of the membrane-soil separation model for the mechanical recovery of residual membrane in farmland

为明确农田残膜机械回收过程中膜土分离机理,基于土壤接触理论及土壤黏附力学,建立残膜与土壤颗粒的接触模型和残膜与土壤颗粒间黏结合力变化的数学模型。利用EDEM软件,进行0.01、0.02、0.03 mm厚度残膜与黏附土壤剥离剪切仿真试验。拟合结果表明,0.01、0.02、0.03 mm残膜厚度下,膜土分离剪切力与剥离剪切位移均呈三次方关系,决定系数分别为0.805 9、0.872 2、0.878 4;对台架验证试验结果进行拟合,决定系数分别0.793 2、0.854 8、0.869 0,相对误差最大值为13.77%。

In order to clarify the mechanism of membrane-soil separation in the process of mechanical recovery of the residual membrane in farmland,a mathematical model of the contact model between residual membrane and soil particles and a mathematical model of the change law of binding force between residual membrane and soil particles was established based on soil contact theory and soil adhesion mechanics.The EDEM software was used to carry out the peeling shear simulation tests of the residual film with the thickness of 0.01,0.02 and 0.03 mm.The fitting results show that there is a cubic relationship between membrane-soil separation shear force and peel shear displacement under different residual film thickness,and the determination coefficient R~2 were 0.8059,0.8722 and 0.8784,respectively.The coefficients of determination R~2 were 0.7932,0.8548,0.8690 by fitting the bench verification test,respectively.It is found that the maximum relative error was 13.77%.