Wear of Particular Agricultural Tractor Tires for Different Field Operations in Africa

Abstract

The overall objective of this study was to analyze the wear rate of tractor R-1 radial tires under specific operating conditions. The specific objectives were to examine the wear rate of the tires (a) when operating under different soil conditions and (b) different field operations, (c) to develop predictive models for the wear rate for both the front and rear tires under specific operating conditions, and (d) to validate the predictive models using measured values.

A Massey Ferguson 385 four-wheel drive (4WD) tractor with 56 kW engine power and 49 kW power take-off (PTO) was used to plow, harrow, and plant three different agricultural fields (Field 1, Field 2, Field 3). Each tire of the tractor was divided into four sections. On each section, three data points were positioned on each lug (tread). A Fowler digital gauge was used to measure the height of the tire lug at each data point before and after every operation. Baseline data was collected on each tire and analyzed, and a predictive model of the wear rate was developed and validated for each tire.

This experiment showed that a tire's wear rate increases as draft force, wheel slip, and soil moisture increase, and decreases as soil bulk density and tractor speed increase.

Also, the tires tended to wear faster on sandy soil compared with loam and clay soils. Additionally, the tires on the right side of the tractor wore faster than those on the left. For example, on Field 1, the rear right tire had a 5.46% higher wear rate than the rear left tire, while the wear on the front right tire exceeded that of the front left tire by 5.40%. The analysis of the predicted wear rate from the developed models versus the actual measurements showed that (a) the front left tire model has a high positive correlation of 0.84 (r = 0.84) and a coefficient of 0.77 (r² = 0.77), (b) the front right tire model shows an r of 0.83 and an r2 of 0.77, (c) the rear left tire model has an r of 0.71 and an r2 of 0.51, and (d) the rear right tire model has a correlation of 0.75 and a coefficient of 0.56. The study also estimated that to maintain uniform tire wear for a Massey Ferguson 385 4WD tractor operating within the context of this study, the two front tires should be swapped approximately every 1,475 ha, and the two rear tires should be swapped after about 1,105 ha. This paper further estimates that the maximum surface area that tires can cover before needing replacement is between 2,719 and 3,221 ha for the front tires, and 1,716 and 3,100 ha for the rear tires.