Measurement of the frictional coefficient of tire rubber for farm use vehicle

Abstract

In this paper, the results of the measurment of the frictional coefficient of the tire rubber to the various surfaces are reported.
Three kinds of boxes having the different contact area of tire rubber attatched to the bottoms of them were prepared and pulled. Vertical load was added to each box in each test. The pulling force of the box was detected with the load cell with strain gage on it. Four varieties of surfaces were prepared. Those were: wood, soil, mortar and concrete. For soil and concrete surfaces, the Amonton's law was valid, but not to the others. In general, the measured static coefficient of friction was larger than the kinetic one.
An obvious result on the relation between the kinetic coefficient of friction and the relative moving velocity of tow bodies was not obtained. Soil constant measuring instrument, TN-4 was used to see the validity of the obtained data by the pulling method. Both results were quitely coincident.