A computer-controlled "Vibratory Bulldozer and Plow" testbed was designed and built to evaluate the effectiveness of vibratory earth moving and tilling tools with emphasis on draft force reduction. The testbed consisted of a mechanical bulldozerand plow unit with vibrating blades, sensors and actuators located in a steel box containing the soil sample. The testhed's control system had the capability to regulate the forces, the frequency of the vibrating actuators, and the longitudinal velocityof the unit.The forces required to push the blade through soil with and without applied vibrations were measured and compared. Tests were conducted on: a scaled bulldozer blade, a moldboard plow, and a chisel plow. Experimental results showed 71 to 93 draft forcereductions while applying vibratory motion in the longitudinal direction. These results were verified on several soil types and conditions ranging from dry (0 moisture d.b.) sands to highly cohesive wet clays. The significant force reduction factorssuggest that the vibrating blade reduces soil strength by decreasing cohesiveness and effective stress for dry to ductile soils. The frequency dependency of the soil resistance indicates that the mechanical power delivered to the soil is also a junctionof the frequency.
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