Experimental and Numerical Investigations of Tractive Performance of Off-Road Tires on Gravel Terrain

In this work, an indoor soil-bin is designed to investigate the tire–terrain interaction mechanisms for the off-road tires rolling on the gravel terrain. The soil-bin test is carried out by the indoor soil-bin experimental device and the three-dimensional (3D) finite element (FE) and discrete element (DE) coupling method under the same particles conditions, respectively. First, with the indoor soil-bin measurement system, the repeatability of the soil-bin experiments is employed to validate the experimental device and the numerical models. Moreover, the tractive performance experiments of the off-road tires with two tread patterns, smooth and grooved interacting with gravel terrain, are performed at the slip of 10%, 20% and 30%, respectively, to obtain the tractive force and the rim sinkage. Second, the corresponding numerical models are also established, and simulated by the FE–DE coupling method, where the FEM and the DEM are used to describe the off-road tires and the gravel terrain, respectively. The tractive mechanisms of the off-road tires in interaction with the gravel terrain such as the tractive force and the rim sinkage are investigated numerically. Meanwhile, The dynamics and discontinuity of the gravel assembly are described by the presented approach. Besides, both the results of the simulations and experiments indicate that tread patterns and slip conditions have great influence on the tire tractive performance. Finally, the numerical simulations and the experimental results qualitatively show good agreements, which certifies the effectiveness of the FE–DE coupling method in the tractive performance analysis of tire–gravel terrain interactions.