Simulation Analysis And Experiment On The Quality Of Vibratory Subsoiling In Hilly And Mountainous Regions

As one of the four basic protective farming practices for farmland,subsoiling can not only break the hard plough pan caused by long-term cultivation,but also improve the permeability and heat capacity of the soil,improve the three-phase comparison of the soil,and create a superstructure of virtual and solid coexistence.Vibration has a great influence on the disturbance state,disturbance effect,vertical accumulation angle,surface furrow shape and traction resistance.Aiming at the rapid development of vibratory subsoiling technology and the lack of comprehensive analysis and research of vibrating and non-vibrating subsoiling in hilly and mountainous areas,this paper adopts the method of combining discrete element method simulation and soil subsoiling operation test to compare and analyze,and the effects of vibrating and non-vibrating subsoiling on soil disturbance state,disturbance effect,longitudinal accumulation angle,surface trench shape,and traction resistance are discussed,which provides a basis for the selection of hilly and mountainous subsoiling methods and the rationality and economy of power supply.The purple soil of the hilly and mountainous area in Chongqing was selected,and the texture,moisture content,density,shear strength and firmness of the loam used in the soil test were determined by sieving,drying,ring knife,and direct shear tests.Based on the physicochemical properties of the purple soil in the hilly and mountainous areas of Chongqing,the soil model was established by EDEM,and the soil disturbance behavior,disturbance effect,vertical soil accumulation angle,surface furrow shape,and traction resistance were compared and analyzed through simulation and comparison between vibratory subsoiling and non-vibrating subsoiling.The overall scheme design of the small farming test platform and the simulation analysis of the mechanical performance of key components are carried out,focusing on the mechanical analysis of the frame,gear and rack transmission system based on ANSYS-Workbench and ADAMS.Based on a small tilling test platform,a vibratory subsoiling operation quality test was carried out,and the effects of vibratory subsoiling and non-vibrating subsoiling on soil disturbance behavior,disturbance effect,vertical soil accumulation angle,surface furrow shape,and traction resistance were compared and analyzed.The main conclusions of this research are as follows:(1)The texture of the loam used in the experiment was loamy sandy soil;the soil moisture content of the cultivated layer was 13.67%,and the soil moisture content of the plow bottom was 20.36%.The soil density of the cultivated layer is 1.49g/cm~3,and the soil density of the plow bottom layer is 1.67g/cm~3.The relationship between the soil shear strength and pressure of the cultivated layer is y=0.340x+16.21,and the relationship between the soil shear strength and pressure of the plow bottom is y=0.288x+25.24.In the test soil,the soil in the 0～10cm layer is loose,the soil in the 10～30cm layer is looser,and the soil in the 30～40cm layer is tighter.(2)Compared with the non-vibrating subsoiling,the vibrating subsoiling has a greater disturbance to the bottom soil of the plough,the upper ditch width is reduced,and the lower ditch width is increased.The bulkiness of non-vibrating subsoiling and vibrating subsoiling are 27.1%and 24.5%,respectively,and the disturbance coefficient is 62.1%and 68.3%,respectively.Unlike non-vibrating subsoiling,the bulkiness of vibrating subsoiling soil Small,large disturbance coefficient.The average value of the longitudinal accumulation angle of the surface soil after non-vibration subsoiling and vibratory subsoiling is 18.9°and 16.4°,respectively.Compared with non-vibrating subsoiling,the vertical accumulation angle of vibratory subsoiling soil is reduced by15.2%.The average resistance of vibrating and non-vibrating subsoiling is 427N and542N,respectively.Compared with non-vibrating subsoiling,the traction resistance of vibrating subsoiling is reduced by 21.2%.(3)Under non-vibration subsoiling and vibrating subsoiling conditions,the average errors of the simulation results and test results of soil bulkiness and disturbance coefficient are 11.0%and 12.6%,respectively.The average error between the simulation results of the soil longitudinal accumulation angle and the test results are 9.5%and 11.0%respectively.The average errors of the simulation results of the upper furrow shape and the test results are 16.4%and 13.8%,respectively,and the average errors of the simulation results and the test results of the lower furrow shape are 11.1%and 14.1%,respectively.The average error of traction resistance simulation results and test results are 14.5%and12.0%,respectively.These errors are all within 16.5%,indicating the feasibility and reliability of the discrete element method simulation.It provides a new method to study the influence of different subsoiling methods on the effect of soil subsoiling,and it has certain reference significance for the reasonable selection of subsoiling methods.