Experimental And Fea Study On Tire-soil Contact Based On Tire Sinkage

Tire/terrain interaction has been an important and complex research topic in terramechanics. The agricultural equipments need to have good tire mobility for well operation and little compaction effects on the farmland soil to ensure soft soil for crops. The research on tire and farmland soil interaction model helps to obtain the deformation pattern of tire and farmland soil in different pressure and load configurations, the change of tire footprint, and the stress and its distribution on tire/soil contact interface. These results can provide references for improvement of agricultural vehicle performance, slowing down farmland tillage layer compaction damage, and increasing the yield of crops. In this paper, 7.50-16, the drive tire of small farm tractor is discussed, and the main contents and conclusions are as follows:(1) Tire subsidence experiments were carried out in two types of soil environment(simulation of arable land and stubble-field), which get the principle of tire sinkage in different tire pressure and load configurations. Simultaneously, the two main experimental factors’ effects on tire subsidence and soil physical parameters which can reflect soil compaction were also studied.(2) The main conclusions of the experiments are as follows: On the stubble-field, The relationship of tire sinkage with load is linear increasing, while with the tire pressure is a S curve function; On the arable land, tire sinkage changes with load as a quadratic function, while with the pressure is a cubic function; On arable land and stubble-field, the effect of tire pressure, load and their interaction on tire sinkage all have a significant level, while the load is more remarkable than other factors; Soil bulk density and soil hardness which reflect the degree of soil compaction of the two types of farmland soil increase with the increase of tire pressure and load, while moisture content decreases.(3) The soft-flexible tire-ground contact model was established in ANSYS, and was verified with the tire subsidence experiments results. And the static simulation analysis was carried out using the verified correct and effective model in different tire pressure and load configurations.(4) The static simulation conclusions are drawn: In diverse tire pressure and load configurations, the distribution of tire stress is annular, and the effect of tire pressure on tire stress is greater than that of load; In arable land and stubble-field, the surface of tire-soil contact is a superposition of irregular rectangular and oval, but the two geometries’ proportion of the surface area is different; And the shape of contact area is more effected by load, but ground stress on the contact area is more effected by tire pressure; In different configurations, the soft arable land, whose distribution of Mise stress is oval, and disturbance of scope and depth is expanding radially with the increasing of load; Soil compaction that extends with the increasing of tire pressure and load mainly concentrates on the depth range of 60 ~ 200 mm.