Study On The Effects Of Plough’s Working And Structure Parameters On Its Resistance Under Rheological Soil Conditions

High resistance and energy consumption are the main features of tillage operation. Improving the efficiency of energy utilization of tillage machinery or soil processing machinery or decreasing the energy consumption of the machinery under the condition that the agriculture requirement is satisfied is widely concerned. For paddy fields, a large proportion of total cultivated area in China, since the lack of the profound understanding for the interaction between soil and the machinery. There is little theoretical basis for the design of paddy soil’s mechinary, which makes the energy can not be utilized effectively.In order to seek a theoretical basis of tillage component’s design for paddy soil and to investigate the affect of the rheological properties on the tillage performance, the tillage resistance under different soil conditions, working parameters and structure parameters was analysed in the paper. Aiming at the minimum tillage resistance for operation, the factors effecting tillage performance and the effecting principle were put forward, which has an important significance and practical values for the design of tillage component.Regarding plough as the research object, aiming at the minimum power consumption for operation, with the methods of kinematics analysis, numerical simulation and optimal design, the following research was carried out:1. The interaction between plough and soil was analysed. The force on the plough in the process of tillage was analysed based on the working theory of two-surface and three-surface wedges. And the mathematical model of plough’s resistance was built.2.3D model of plough was built. Based on existing plough, point data of plough’s surface were obtained by three-dimensional measuring machine. With reverse engineering technique,3D reconstruction was conducted with Pro/E in order to attain computational model of plough surface. And parametric design for plough was done with plough’s computational model as a sample.3. The expression method of soil rheological parameters in the simulation processing was studied. The basic mechanical parameters of soil are measured. And the soil’s rheological parameter is one of the facors in the experiment of soil-bin. In the processing of simulation, the rheological parameters were convered into Prony series.4. The finite element model of plough and soil was set up, and the interaction of plough and soil was analysed by the numerical simulation. Utilizing the software ANSYS, the finite element model about the interaction between plough and soil has been developed. Through 3D analyzing, the real-time dynamic change in resistance of plough in the whole tillage process was obtained. With simulating under various tillage speeds, the change rule of the tillage resistance was studied. The error between simulation results and experiment data in soil-bin is within 10%. It shows that the numerical simulation is feasible.5. The affect of different tillage conditions on specific resistance was analysed by soil-bin experiments. Orthogonal tests with four factors, involving model of plough, tillage speed, tillage depth and soil’s rheological parameters, and three levels were carried out on the specific resistance in soil-bin. The affect of experimental factors on experimental index is analyzed. Through regression analyzing, the interaction relationships for tillage specific resistance and model of plough, tillage speed, tillage depth and soil’s rheological parameters were obtained. The test showed that tillage depth, model of plough and tillage speeds have significant impact on the soil tillage specific resistance. The optimal combination among experimental factors was observed. Besides, the displacement field and stress field were measured at premise of the same tillage depth.6. The affect of different structure parameters on specific resistance was analysed by simulation. At premise of the optimal combination among plough’s working parameters, orthogonal tests with four factors, involving pushing angle, rake angle, covering angle and height of plough, and three levels have been carried out on the specific resistance by numerical simulation. The result showed that the affect of covering angle on specific resistance can be ignored. And the regression equation for tillage specific resistance and pushing angle, rake angle and height of plough was obtained.7. The structure parameters of the plough were optimized. By means of the numerical simulation, using the specific resistance as target function, the mathematical model for optimization design for the main structure parameters of the plough was set up. Then the optimization of specific resistance was carried out by using the constrained nonlinear funetions in MATLAB. At last, the optimal combination among the three main stand-alone variable parameters affecting the specific resistance which includes the pushing angle, rake angle and height of plough was obtained. Experiments demonstrated that comparing with the resistance of initial plough, the resistance of optimal plough decreased by 26.60% at most and by 6.77% at least.8. The performance of optimal plough was verified. According to the law of turnning, the turn performance of optimal plough is detected in the ANSYS. The result of detection shows that the performance of optimal plough is satisfactory.