| In order to solve the problem of large tool resistance when the southern economic forest is during deep loose.Based on the camellia forest subsoiler developed by the research group,carrying out deep loose tool design and structural improvement,and studying its resistance characteristics.Because the deep loose tool is a component that directly acts on the soil,the design of deep loose tool of the woodland is particularly important,and the values of the tool motion parameters and structural parameters will directly affect the magnitude of the deep loose resistance and the effect of the quality of the job effect of subsoiling.In this paper,the parameters of the deep loose tool of the woodland,the analysis of the resistance characteristics of the deep loose process,the dynamics simulation of the deep loose process,and the fitting simulation data are used to optimize the tool.Finally,the field test proves that the simulation is reliable and the optimization effect is good.Developing a tool suitable for deep loose forests to meet the needs of economic forests is necessary,the main research contents are as follows:(1)According to the requirements of economic forest deep pine tending hor ticultural requirements,determining the motion parameters and structural paramet ers of the deep loose tool.According to the tool structure parameters,analyzing and verifying whether the rotational speed in the motion parameters meets the requirements of soil particle lifting.Constructing a mathematical model of tool r esistance characteristics during deep loosening and analyzing the main factors af fecting the deep loose resistance.(2)Based on the SPH method,the dynamic simulation of the deep loose process by woodland deep loose tools is carried out.Studying the deep loose resistance of the tool under different spin ratio,cutting angle and blade angle,and getting the best combination of motion parameters and structural parameters.And analyzing the deep loose resistance under this combination of parameters.(3)Based on SPSS,the 3×3 simulation resistance values are fitted to the equation and getting the analysis of the significance of equations and parameters.By analyzing the resistance characteristics of the deep loose process,obtaining the constraints of various parameters of woodland deep-cutting tools.Using the fmincon function in Matlab to optimize the tool and the dynamics to verify the optimization results.(4)Carrying out the field test of deep loose resistance and analyzing the influence degree of various factors on the deep loose resistance under actual conditions.Verifying the reliability of dynamic simulation based on SPH method and the goodness of optimization effect,and providing data support for simulation and optimization.The results show that the 3×3 orthogonal table obtained by the dynamic simulation of the deep loosen process and the field test can conclude that the resistance value is minimum when the rotational speed ratio is 4.39,the cutting angle is 30°,and the blade angle is 30°,1.17 and 1.11KN respectively.And the numerical error of the test and simulation is within an acceptable range.Therefore,simulation and subsequent optimization are reliable.Based on SPSS,equation fitting of 9 sets of simulation values to analyze the constraints of various parameters in the deep loose process.Based on Matlab,the fitting equation was optimized under the constraint condition.After optimization,when the rotation speed ratio is 12.75,the cutting angle is 15°,and the blade angle is 20°,the deep loose resistance of the woodland deep loose tool is the smallest,which is 0.976KN.And the simulation of the optimized tool is verified by LS-DYNA,and the optimization effect is remarkable.Finally,the field test is carried out.Under the same conditions,the relative error between the 3×3 test and the simulated value is less than 10%.And the resistance before and after optimization decrease by 15.2%.Therefore,the simulation and optimization are reliable,and the optimization effect is obvious. |
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