Soil Dynamic Behavior Of Planting Pore-forming Process Based On Discrete Element Method

Research on soil dynamic behavior in the planting forming hole operation process under the action of the vertical penetrate type rape transplanting machine.In this paper,by using discrete element software to simulate pore-forming parts vertical penetrate in soil forming hole operation process,explored pore-forming parts and soil interaction mechanism,and research on pore-forming transplanting hole influence law by stab structure parameters and motion parameters.at last,verified the simulation test results feasibility and reliability by indoor soil bin test,main conclusion were as following:1.Through basic physical test obtained southern typical soil intrinsic physical parameters;Base on virtual calibration test method,soil repose angle as evaluation index to obtained soil contact mechanics parameters.Finally established the soil particles contact mechanics model.2.Through establishing discrete element pore-forming operation simulation system,research on interaction principle between pore-forming parts and soil,the results showed: the diameter of stab,stab tip chamfering and penetrated depth were all effect pore-forming resistance significantly,stab optimal parameters was 52 mm in diameter,40 ° in stab chamfer,86.30 mm in penetrated depth;the stab tip chamfering main control soil moving orientation,when the angle of tip chamfering was small,stab tip main function was cut soil layers,soil move around the stab,pore-forming resistance was weak,when the angle get bigger,stab tip main function was push soil to deep layers,soil layers were harder and pore-forming resistance was strong;the diameter of stab and penetrated depth mainly control soil force area,the pore-forming resistance will raise with the stab diameters get bigger or stab move deeper3.Using home-made small-sized soil bin to do stab pore-forming resistance verify test.Results show that the pore-forming resistance variation trend between soil bin test and simulation test were basically same,relative errors were less than 10%,the optimal parameters soil bin pore-forming resistance test result was 54.7N,relative errors was 6.4% compare with simulation result.