Experimental investigation for wedge interaction with granular media

Abstract This study experimentally investigates the drag resistance and lift force acting on a wedge moving horizontally in granular media under low-speed conditions. The results show that the relationship between drag resistance and velocity varies across different wedge shapes, whereas the lift force generally decreases with increasing velocity regardless of the wedge geometry. Notably, during the initial stage of motion, the wedge experiences a reverse lift force, which acts in the opposite direction to that observed under steady-state conditions, and the impulse generated by this reverse lift decays exponentially as velocity increases. In addition, the experimental results indicate that the density of the tested wedge has no significant effect on either drag resistance or lift force. These findings highlight velocity, shape, and penetration depth as the primary factors influencing the forces acting on a wedge in granular media. This study provides important experimental insights for the design and control of robots capable of efficient locomotion in sandy or soft terrains.