Finite Element Simulation And Optimization Of Rotary Blade Of Mini-tiller Based On SPH Algorithm

Mini-tiller, with characteristics of small scale, lightweight, easy handling, etc., is suitable for operations in upland and water field of small area in hilly regions, and there are wide application prospects for these tillers in China. The driving force of the mini-tillers is ultimately transmitted to the rotary blade, and the rotary blade interacts with soil to achieve soil turning and pulverization, improve soil structure, eliminate weeds, cover the stubble and improve soil performance. Therefore, in order to obtain good performance of soil-turning, pulverization and soil-mixing and reduce the rotary tiller resistance, theoretical analysis and optimization design of structural parameters and operating parameters of the rotary blade are necessary.In this paper, take example for the soil of Chongqing Municipality, we utilize smooth particle hydrodynamics (SPH) algorithm and the finite element method for the simulation of a rotary blade cutting soil values.In this paper, taking the soil of Chongqing Municipality as an example, the simulation of a rotary blade cutting soil was conducted by means of Smooth Particle Hydrodynamics (SPH) algorithm and the finite element method. The main contents of this study are as follows:(1) Static force analysis was conducted based on finite element analysis software ANSYS. The analysis shows that the maximum stress occurs at the conjunction of the shank and the lateral edge of the junction, and the maximum deformation occurs at the tangent part of the rotary blade.(2) By means of SPH algorithm and LS-DYNA, combined with MAT147 material soil model, the process of cutting soil of the rotary blade was simulated, and the stress between the rotary blade and the soil, the cutting resistance and the power curve were obtained.(3) The effects of the velocity of the rotary blade, tillage depth and width on the power consumption were compared and analyzed, and the rotary blade structure and motion parameters of the rotary blade were listed.(4) By the simulation of rotary blade cutting process, the effect of bending angles on the power was analyzed. Symmetric fillet was added to the conjunction of the blade holder and the cutting edge of the blade, which reduces the maximum stress and increasing the strength of the rotary blade.By means of SPH algorithm, the cutting process of the rotary blade was simulated. The process of soil destroying of the SPH soil particle by the acting of rotary blade is studied. The equivalent stress and the strain law in the soil and the rotary blade in the cutting process were obtained, and the power consuming of the rotary blade while cutting soil under different conditions was compared and analyzed. The results show that, based on mini-tiller rated power, selecting the appropriate structure parameters and motion parameters of the rotary blade can effectively improve the work efficiency of the mini-tiller.