Bionic Design of Sandfish (Scincus scincus) Head Inspired Subsoiler Tine and Its Performance Evaluation by DEM

Abstract

Abstract. Subsoiling consumes huge amount of energy in tillage operation. with the purpose of mitigat-ing this problem, it was found sandfish (Scincus scincus) has excellent ability of moving effec-tively below soil. The special geometrical feature of sandfish head provided an excellent bionic prototype for the design of novel subsoiler tine and reduce soil breaking force of subsoiling. Thereby save energy and improve operating efficiency. In this study, three innovative bionic subsoiler tines B-T-1, B-T-2, and B-T-3 were designed by learning from the special feature curves of sandfish head. The commercialized and extensively used traditional tine T-T was used as a control. Tines were assembled into four with arc-shaped shank subsoilers T-S, B-S-1, B-S-2, and B-S-3. To investigate the effect of the bionic subsoiler tines on tillage force and the reveal the in-teraction mechanism between subsoiler tine and soil, the discrete element model (DEM) was used to simulate the subsoiler tines in a virtual layered soil bin. The results showed that bionic subsoiler tines had lower draft and vertical force. At the operation speed of 0.8 m/s, under the condition of tillage depth of 300 mm, compared to T-S, the draft force of B-S-1, B-S-2, and B-S-3 decreased by 6.42%, 9.31% and 7.96%, respectively, and the vertical force decreased by 13.13%, 19.31% and 16.99%, respectively. This study provides theoretical and design reference for drag reduction of agricultural tillage components. Through the actual vertical penetration test and using the DEM simulation, the Pearson correlations between the test and simulation results of T-T, B-T-1, B-T-2 and B-T-3 were 0.9942, 0.9931, 0.9899, and 0.9886, respectively, which proved that DEM had a good predictive effect on the actual test. This study provided a novel bionic design approach that by learning from special feature curves of sandfish head to reduce the energy consumption of soil-engaging component of agricultural machinery.