Development of Vertical Vibration Model for Micro-Tiller by Smoothed Particle Hydrodynamics Method

Abstract

A micro-tiller vibrates severely during the rotary tillage process, which may cause operators to develop white finger disease. However, for most vibration models, the acting force between the soil and the rotary cutter roll was simplified to only a constant or sine curve, which may not describe the whole dynamic. Rotary tillage processes have been simulated based on the smoothed particle hydrodynamics method in this paper. The acting forces of the soil on the cutter roll have been obtained with the simulation model. Four different working conditions were simulated. The average error between the calculated forces and the simulated mean forces is 10.96%, which proves the SPH model. By introducing simulated acting forces into the vibration model, a new vibration model of the micro-tiller, which includes the soil–blade interaction, has been constructed. Time and frequency characteristics were simulated with the new vibration model. The errors between the simulated and tested RMS values are 4.28%, 5.03%, and 6.35% for the engine, cutter roll, and right handle, respectively. Two domain-dominant frequencies were found with the vibration model, namely 44.7 Hz and 257.0 Hz. It is helpful to reveal the whole dynamic map of micro-tillers.

Keywords

• rotary tillage
• micro-tiller
• vibration
• smoothed particle hydrodynamics method
• time–frequency characteristics