Experimental Research Of Furrow Openers Based On DEM

Furrow opener is one of the important components of seeding and fertilizer machine. Theperformance of furrow opener affects the quality of the whole seeding (fertilizer) machine. To studythe soil-implement interacting, finite element method (FEM) is a traditional method. With FEM soilparticles is taken as a whole part. While in the process of cultivation is accompanied with thecracking and mix of soil layer and the flow of soil particles, so FEM has a limit to study thesoil-implement interacting. Discrete element method (DEM) is a discrete numerical simulationmethod to analysis dispersed particles, which is proposed by Cundall in1970s. As a kind of typicalcomplex particles aggregate, soil has obvious characteristics of symmetrical dispersed particles. Souse DEM to analyze soil-implement interacting is completely suitable.In this paper, the research mainly includes two parts：one is testing the working process of thefurrow opener by glass soil bin and another is using discrete element software to simulate theprocess of the furrow openers. A typical black loam of Changchun area is selected in the soil bintest. The physical and mechanical properties of soil were tested to confirm the characteristics of soiland some parameters of the discrete element simulation. According to these parameters apreliminary simulation of the core furrow opener is simulated and obtained one data. And then thesoil bin test of core furrow opener has been carried out by the method of comprehensive test. Halfof the soil bin is build with transparent glass and core furrow opener and sliding knife furrowopener are chosen for the soil bin test. Tension and compression force transducer and dynamicstrain testing system were used to test the horizontal and vertical resistance of the furrow openers.The soil was layered for shooting the soil disturbance in the working process of the furrow openersby high-speed cameras from different angles.The preliminarily model is error through the comparison between results of simulation and thesoil bin test. After parameter modification, the simulation has been restarted. The workingresistances of the core furrow opener gained by the simulation and soil bin test have a goodrelationship when using the modified simulation model. And the simulation process of screenshotscompared with the result of the high speed camera found similar soil disturbance situation, provedthat the rationality of the parameters of the model. In the model, the soil particles contact model isHertz-Mindlin bonding model. The normal stiffness between soil particles is13000~25000N/m andthe shear stiffness is9000~19000N/m; the critical normal stress is50000~62000Pa and the criticalshear stress is25000~35000Pa. In order to verify the generality of soil model, a simulation ofsliding knife furrow opener has been carried out. A good correlation has been gained between theresults of the simulation and the soil bin test, which further provides the rationality of the parameters of the model.Through the two openers’ soil bin test and the discrete element method simulation test showsthe advantages of using the discrete element method for soil-mechanical interaction research. Theresults of the article provide a new thought and a new method for the design and optimization offurrow openers.