Modeling And Simulation Of Soil Cutting Dynamics Of Rotary Roller Of Mini-tiller

Mini-tiller, with characteristics of small size, light weight, easy handing and easy to move, is suitable for operations in hilly regions, small land with water, and greenhouse, and has been widely used in China. It plays a very active role to improve farming mechanization on hills and mountains. The power of the mini-tiller is eventually transmitted to the rotary roller, and the rotary roller interacts with the soil to achieve pulverization and soil turning, change the soil structure and eliminate weeds, and at the same time help the mini-tiller run. The traditional experimental method is difficult to quantitatively describe the performance of rotary roller, because the soil has multiphase, loose and dispersion properties. Computer simulation of rotary roller soil cutting can be easily and quickly conducted the soil cutting process of rotary roller, quantitative analysis of the power of the rotary roller, and it provides a theoretical basis for structural optimization design and arrangement of rotary roller.The present study, taking the mini-tiller as a prototype which is widely used at the hilly regions in south China, builds the finite element model based on the soil characteristics in south China, and uses the Smoothed Particle Hydrodynamics to simulate the soil cutting process of rotary roller by comparing the simulation data and the theoretical data so as to provide a theoretical basis for optimal design of the machine and mechanical parts of mini-tiller. The main contributions of the study are as follows:(1) Modeling for rotary blade and rotary roller in3D modeling software PRO/E based on the pre and post processer LS-PREPOST of LS-DYNA was conducted, and the finite element parameters of the soil to establish the soil SPH model were defined.(2) The distribution of stress and strain when the rotary blade is under stress, by using the finite element analysis software ANSYS to conduct the static analysis for rotary blade, was found out.(3) The stress-strain variation of rotary blade in different conditions through the static analysis at different bending angles and different blade widths was obtained.(4)By analyzing the characteristics of rotary roller operation, combined with elastic-plastic theory, the suitable models for finite element analysis simulation by using the Drucker-Prager nonlinear elastic-plastic model to simulate soil cutting process were established, and the stress distribution, the cutting resistance and power consumption in the soil cutting process of soil and rotary roller were obtained.(5) Through the analysis and calculation of power consumption, the applicability of the model and stimulation by comparing with the theoretical value which is calculated in accordance with the cutting parameters was verified.