Modelling of pneumatic tractor tyre interaction with multi-layered soil

A non-linear finite element (FE) model of the interaction of a tractor tyre with soil surface was developed as a procedure for analysing the contact pressure distribution for varying wheel loads and tyre inflation pressures. The tyre model considered the geometry and orientations of the tyre cords in each ply, the near-incompressible property of the tread rubber block, and the high and non-linear deformation of the carcass under the tread. The soil model was simulated with a linear model and considered a realistic soil cross-sectional area of influence with layers separation, including three soil surface layers and a hardpan layer. The three surface layers were within normal tillage depth (soil surface to 250 mm depth), with 250–300 mm hardpan substratum. Tyre–soil interaction model was developed using ANSYS FE software and the results, which describe the influence of the wheel load and tyre inflation pressure on contact pressure distributions were analysed. Results from the simulation were compared with the measured data to verify the validity of the model for soft soil conditions. The comparison showed reasonably good agreement between the computed and measured general pattern of the pressure distribution at the tyre–soil interface under different loads and inflation pressures.