Soil arching effect analysis and structure optimization of a robot foot sinking in soft soil

In this study, to analyze the influence of the cross-sectional shape of a rigid foot on its sinking performance in soft soil, a numerical model of the subsidence of a single leg was built using the arbitrary Lagrangian-Eulerian method in ABAQUS to describe the interaction between the foot and soil. After performing a simulation of circular, annular, X-shaped, and improved X-shaped feet, all with the same cross-sectional area, the end resistance, side resistance, and distribution of contact pressure along the radial direction were analyzed. The simulation results showed that the soil arching area caused by the hole at the bottom of a rigid foot can effectively increase the end resistance and that the side resistance increases with an increase in the side perimeter. The end resistance and side resistance of the improved X-shaped robot foot were higher than those of the X-shaped robot foot during the sinking process. The effects of the improved geometric parameters of the X-shaped robot foot on its sinkage were analyzed through orthogonal experiments. The simulation results can provide a reference for the future structural design and optimization of robot feet working in soft soil environments.