Date of Award


Document Type


Degree Name

Doctor of Philosophy (PhD)


A mechanically balanced oscillating inclined digger blade mechanism was designed and constructed to evaluate the effects of vibration on soil break-up and power requirements. Changing the levels of amplitude, frequency, and forward travel speed, twenty-seven combinations of such parameters were tested in two different soil conditions. Soil conditions for this study are based on a silt loam soil with moisture contents of 16 and 15 percent (w.b.), dry densities of 1440 and 1310 Kg/m('3), and cone indices of 0.82 and 0.41 MPa for hard and soft soil conditions, respectively. The variables measured were geometric mean diameter (GMD) and its log standard deviation of soil clods, draft, mean torgue, and maximum torque. Power requirement was derived by summing draft and shaft power based on the draft and maximum torque. Soil conditions changed the draft, maximum torque, and total power requirements but no significance was observed for GMD and mean torque. Vibration effects were significant on the torque and total power requirements but only amplitude caused significant differences in the responses of GMD. Forward travel speed resulted in significant change in the draft and total power requirements. The major portion of total power was used as shaft power to oscillate the vibrating mechanism.