Upper-Bound Analysis for Soil Thrust of Single-Track System over Clay Ground

Abstract

Soil thrust acts as a reaction force that enables an off-road tracked vehicle to overcome motion resistance and move the vehicle forward. Thus, the estimation of soil thrust for a track system has great importance in the design and path planning of off-road tracked vehicles. In this study, we first present analytical solutions for the soil thrust of clayey ground by performing an upper-bound limit analysis, as a basis for the assessment of the tractive performance of off-road tracked vehicles. Two different failure modes (block and triangular wedge) are possible on a soil-track interface, and the resultant soil thrust is determined as an upper-bound solution for the most critical failure according to the principle of least action modes (i.e., the least-upper-bound solution). Based on the upper-bound solutions, parametric studies were conducted to explore the effects of the shear strength of clayey ground, geometry of a track system, and the weight of the vehicle on soil thrust. For practical use, this study also offers a soil thrust design chart for a single-track system.