3D Finite Element Simulation and Experimental Validation of a Mole Rat's Digit Inspired Biomimetic Potato Digging Shovel

Featured Application This work proves the feasibility and effectiveness of biomimetic macroscopic surface modification method to reduce the draught force of potato digging shovels based on mole rat's digits, which is also a reference and experience for the optimization and modification of other soil engaging components. To reduce the draught force of a traditional planar potato digging shovel (DZ), a biomimetic potato digging shovel (YS), inspired by the mole rat's digits, is designed, using the biomimetic macroscopic surface modification method. The finite element simulations, soil bin experiments, and field experiments for DZ and YS are conducted to explore the factors affecting draught force and to verify the feasibility and effectiveness of the biomimetic potato digging shovel. Results show that the soil-shovel interaction models predict the draught force well, but the simulations for the soil rupture distance ratio need to be further improved. The studied factors all have a great influence on the draught force of DZ and YS and they follow the order of cutting speed > digging depth > mounting angle. For the single shovels, YS, compared with DZ, increases the draught force at a low mounting angle but decreases the draught force by over 8.41% when the mounting angle is higher than 30 degrees; for the grouped shovels, the draught force and fuel consumption of YS, compared with those of DZ, decline by over 13.33% and 9.18%, respectively. The reasons for the reduction in the draught force of YS are to make the soil mass tend to move upward and to change the soil's state of motion and stress continually; thus, the compaction to the soil is reduced, and the soil becomes easier to be broken.