Comparison of the forest machine mover average and nominal pressure on the soil

The purpose of this article is to investigate the relationship between the estimated values of nominal and average wheeled mover pressure on the ground and a rigid bearing surface. Research methods are mathematical analysis, computational experiment, and calculated data approximation. The article presents and compares methods of calculating average mover pressure in deformable soils, medium mover pressure on a rigid base, and nominal pressure on soil. According to the calculations results, it was found that the average mover pressure on firm soils almost corresponds to the estimate of the mover pressure on a rigid base. The nominal pressure is lower than the pressure on the rigid base by 40-50 kPa. The average pressure estimate on moderate soils is close to the nominal pressure. The average pressure on weak soils in the load range of 10-20 kN is close to the nominal pressure, at high values of wheel load the average pressure on the soils category is estimated to be twice less than the nominal pressure of the mover on the soils. It has been established by calculation that the average pressure of the wheeled mover on the deformable forest soils and on a rigid base is connected with the value of the mover nominal pressure on the soils, used by the foreign researchers. The dependences are linear and include correction factors, the values of which are determined by the mover parameters (wheel width and diameter, tyre pressure, and wheel load) and the forest soil category. The received equations allow simplifying the interaction estimates comparison process of forest machine movers on the soils, given within the domestic and foreign techniques limits.