Tractive Performances of Wheel-Type Tractor (VIII)

Distributions of the Ground Contact Pressures of the Tire on the Soil Bins

Abstract

Pressure distribution pattern under the tractor tires is the definite tactor for the wheel sinkage and the most important elements for the traction caused by the friction between tires and soil and they were reported by many researchers.
In these reports, they only mentioned as the tire had no lugs and even if they had many lugs, the effects of them were all neglected.
In this test, the effects of lug to the pressure distribution pattern were measured and it was clarified that the lug had the large effects for the distributions as in figures in this paper.
It was described in many reports that the traction was the results of the shearing resistances of the soil between the lugs. But the pressure of the soil which may be sheared were very smaller compared with the pressure of the soil under the lugs. Accordingly, it may be seemed that the traction were almost indebted by the friction between the soil and the tire surfaces.
In this test, the pressure pattern were measured by the small cone penetrometer like the pencil and the loads on the tire were checked by the total of the ground contact pressures as in the table.