Research On Tea Garden Weeding Mechanism And Machinery Based On Discrete Element Metho

Against the backdrop of vigorously developing agriculture,the tea industry plays an irreplaceable role in China’s economy,and tea has become an indispensable healthy beverage in social life.With the continuous growth of people’s demand for tea,the tea industry has begun to move towards scale and modernization.The management of tea gardens has always been a necessary consideration,which directly affects the quality and yield of tea.Considering the problems of high soil entry resistance,poor weed quality,low efficiency,and high manual operation intensity in the current weeding machinery in Guizhou mountainous tea gardens,and the lack of theoretical basis for the design and research of key components of weeding machinery,this article takes the existing weeding machinery as the basis and conducts investigation and analysis of common weed species in Guizhou tea gardens.The research object is the root soil weeding machinery of tea garden weeds（small grass）,Conduct research on the weeding mechanism and key components of machinery in tea gardens.This paper studies the interaction among weed root soil cutter,establishes a simulation model of the interaction among weed root soil cutter,and explores the relationship between key parameters of cutter and cutter resistance,weed root soil,and weed quality based on this model.The key parameters of weed cutter are optimized and analyzed using Design Expert analysis software.Study the interaction mechanism of weed root soil weeding tool to provide theoretical support for the optimal design of weeding tools.The concrete contents of the study are as follows.（1）"Measurement of physical characteristics and calibration of discrete element parameters of miscellaneous grass roots in tea gardens.".Field investigation of common weed species in tea plantations in Guizhou Province was conducted.The root system and soil of a typical weed,Pegasus chinensis,were taken as the research object.The method of combining physical experiments with discrete element simulation was used to calibrate the discrete element parameters of the root system and soil of Pegasus chinensis,and the discrete element simulation parameters of the root system and soil were established.The root system of Pegasus chinensis was quickly filled using the discrete element EDEM software and the particle rapid filling method,A discrete element simulation model of weed root system was established,and the established root system was verified through three point experiments and shear simulation experiments.（2）Based on discrete element method（DEM）,the interaction of weed roots,soil,and herbicide blades was studied.A weed root soil complex model was established to explore the movement mechanism and weeding mechanism of the soil.Through the simulation of the weed root soil,the changes in the torque and three-dimensional force exerted on the tool were analyzed.It was concluded that the addition of root system increased the force exerted on the tool,and the horizontal force exerted on the tool was greater than the vertical force and lateral force,which was the main source of tool resistance.The higher the rotational speed,the greater the horizontal force exerted on the tool,The greater the tillage resistance,the higher the tillage efficiency and the higher the energy consumption.（3）Using Design Expert analysis software to optimize the design and analysis of key parameters of weeding tools.This paper introduces the classification and characteristics of weeding tools,and analyzes in detail the key design parameter theory of rotary tilling machetes.In order to reduce the soil penetration resistance of the cutting tool and improve the weeding efficiency and quality of the cutting tool,based on existing micro tillage and weeding machinery,the weeding tool is optimized.On the basis of ensuring the basic shape and service life of the cutting tool,we conducted a simulation and optimization analysis of the weeding tool using the tangent end face cutter height and tangent bending angle as variable factors,and the resistance to the blade and the scattering displacement of the small canopy grass root system as target values.Finally,the optimal values of the tool structure parameters are obtained as follows:the cutter height of the tangent face is43.5mm,and the bending angle of the tangent face is 120°.According to the graph of the orthogonal response surface,it can be seen that the height of the tangent surface cutter and the bending angle of the tangent surface have a significant impact on the tool resistance.The main influencing factor of the root dispersal displacement is the height of the tangent surface cutter.Under the condition of ensuring relatively low tillage resistance,compared to the prototype tool,the optimized tool improved the scattering effect on the root system by 29.93%,and effectively improved the efficiency and quality of weed control tillage.Provide theoretical support for the research of weeding micro tillage machinery.（4）Perform finite element analysis on the plow blade.The finite element model of the plow blade was established,and the displacement,stress,and strain analysis of the finite element model was performed.It was found that the stress concentration location was located near the connecting hole of the blade handle and the transition position between the blade handle and the blade back bending curve,with the maximum stress and strain values of 77.15MPa and 9.7×10^-4m/m,with a maximum displacement of 2.31×10^-3m,where the strain is relatively large,it is prone to bending and fracture.This part is the vulnerable part of the tool.Special treatment can be performed on the vulnerable part of the tool to increase its hardness,enabling it to face complex soil conditions.