基于离散元法的耕层残膜拉伸性能研究OA北大核心CSTPCD

Due to the lack of accurate discrete element model parameters in the design and optimization process of the key agricultural machinery components of the plough layer residual film recycling machine,the research on the interaction mechanism between the plough layer residual film recycling machine and the residual film was restricted to a certain extent.Taking the residual film in the tillage layer of cotton field as the research object,the residual film in the tillage layer content and ultimate tensile force were measured,and the residual film content and ultimate tensile force of different tilting depth and thickness were obtained.According to the measurement results,the Hertz-Mindlin with Bonding contact model was selected for discrete element model parameter calibration by using EDEM software.The normal stiffness per unit area,tangential stiffness per unit area,critical normal stress,critical tangential stress,bond radius and contact radius were selected as test factors.Through Plackett-Burman test,the steepest climbing test and Box-Behnken test were used in turn.Finally,the significant parameters of the optimal Bonding model were determined as normal stiffness per unit area,critical normal stress and bond radius,whose values were 2.36×105 N/m3,6.47×104 Pa and 0.004 mm,respectively.The simulation test was carried out to verify the parameters,and the error value was 5.88%,which met the requirements.Through the comparative analysis of the residual film in the tillage layer state and tensile curve of the physical testing and simulation test in the stretching process,the rationality of the residual film model in the tillage layer was proved,which provided theoretical support for the later residual film in the tillage layer recycling machine to simulate the mechanical recovery of residual film in the tillage layer and analyze the separation mechanism of film and soil.