Evaluation of the Soil Thrust on Continuous Tracks Considering Independent Soil Shearing by Grousers

Soil thrust is a traction force of an off-road tracked vehicle. Existing soil thrust assessment methods assume that a continuous shear failure plane exists along the soil-track interface. However, recent experimental works revealed that the soil beneath the track is divided into soil blocks; each soil block is sheared independently. This study proposed a new total soil thrust assessment method based on the block-shaped failure mechanism, and the total soil thrust predicted by the proposed and the existing methods was compared. The results showed that the existing method showed a greater maximum soil thrust at a lower slip rate than the proposed method. When the soil exhibited a hardening behavior, the total soil thrust in the existing method was always greater than that in the proposed method. However, when the soil exhibited softening behavior or hump behavior, the total soil thrust in the existing method was greater than that in the proposed method until a specific slip ratio, after which the latter became greater. Unlike the existing method, the proposed method can consider the difference in soil thrust with the grouser shape ratio, showing that the total soil thrust increased as the grouser height increased and the shape ratio decreased.