The Stress Simulation And Experiment Of Universal Blade For Rototilling Combining Machine

Northeast blackland area is an important bread basket of our country. However the areais confronted with cultivated land decreased and serious soil erosion problem, conservationtillage has become an important solution to solve these problems. Combined tillage ofhigh-power can complete kinds of jobs within one operation, thereby reducing damage to thesoil, and improving the quality of the tillage. However we need to develop new machinery toadapt to the high-horsepower tractors. the structural of the machinery and the performance ofthe soil-engaging component have a great impact on the power consumption of the entiremachinery, therefore much research and experiment required in order to achieve desireddesign effect.With the development of computer technology, computer simulation for example FEMand DEM etc, can make a relatively environment for performance analysis, simulation,evaluation and optimization of specific products, which greatly simplified the design task,and it is have important reference value of the institutional design, validate its feasibility andreliability.In this paper, we studied the general-purpose blade of combined tillage machine withhigh-power. simulated the process of the general-purpose blade cutting soil by the explicitmomentum module in the finite element software ANSYA LS-DYNA, analyzed theinteraction between the blade and the soil, then did some tests to verify the correctness of thesimulation in the laboratory, then checked the result on the blade to optimize the design.In the simulation, we chose the modified soil model of Drucker-Prager, throughliterature review and experimental determination to determine the parameters of the soilmodel. making a definition to the process of the simulation, adding the soil model to thesimulation analysis by modifying the K file, simulating the process and checking the result,we can learned the trends of the three directions contribute, the value of the X、Y、Z threedirections contribute respectively is566.39N、182.18N、278.85N, at the same time we cansaw that there was stress concentration in the side cutting edge of the general-purpose blade.For verifying the correctness of the model, a single-handedly cutting soil experimental system was designed, it included two parts: test systems and data acquisition system. The testresults verified the correctness of the previous simulation, by analyzing the data, within thetest range, when the rotation speed is constant, the larger the blade forward speed, the greaterthe resistance that the general-purpose suffered; when the forward speed is constant, therewas have the same result. For finding the law of the three direction force, we got the fittingcurve by Matlab.X-direction fitting curve is similar to the cosine curve,the equation is:Y-direction fitting curve is similar to the cosine curve,the equation is:Z-direction fitting curve is similar to a parabola,the equation is:There was the stress concentration in the side cutting edge of the general-purpose blade,so we did the optimization design by the Genetic Algorithms of the MATLAB, the sidecutting edge was Archimedes spiral, took the power consumuption as the optimization design,the parameters were ν、R、n、k, and the results were:0.78m/s,0.243m、233n/min、2.78.