Sinusoidal vibratory tillage

One dimensional sinusoidal vibratory tillage was analyzed theoretically and experimentally. A model was developed in which the instantaneous horizontal force on the tool was equal to a constant plus a linear function of tool velocity. The tool action was analyzed in three stages: (1) retraction of the tool, (2) compression of loose soil in front of the tool, and (3) cutting of undisturbed soil. The effect of tool mass was included, but edge effects between the tool and soil as the tool retracted were neglected. Equations were developed for the instantaneous horizontal force on the tool, average force and power requirements for the tool and ratio of average force and power on a vibrating tool to the average force and power for the same tool without vibration but moving at the same average velocity.

The model predicted the measured instantaneous tool force and average force accurately when the tool oscillated at 10 Hz and the soil failed by flow. At higher frequencies, the soil failed by multiple shear resulting in more pulverization. In this case, the model did not predict the instantaneous force accurately but did not predict the average force with reasonable accuracy. Multiple shear was more evident on the 45° tool than the 80° tool, the difference was attributed to the fact that the soil was more confined by the 80° tool. A maximum force reduction of 40% was observed at a contact ratio between 0.3 and 0.4. The power required for the vibrating tool was increased by a factor of 1.5 to 3.0 for the same contact ratio interval.