BIONIC DESIGN AND EXPERIMENT OF EXTRUSION HEAD BASED ON PANGOLIN SCALES

摘要

In order to reduce the working resistance of non-excavating and hole-forming working parts in soil, the surface scale texture structure of pangolin with strong hole-digging ability was studied. The whole surface of pangolin had regular stripe shape (vertical surface structure) in the longitudinal direction, and the surface of single scale had microscopic geometric structure. Then the bionic structure design of the surface of the extrusion hole-forming working part was carried out under this study, and four types of extrusion head were machined. The jacking force and its change in the loading process of the extrusion head under the same conditions were collected through experiments, and the relationship between the surface structure and soil resistance under different working conditions was studied. Then, the relationship between the extrusion head and soil environment was analyzed by finite element method, and the soil resistance under different geometric structures was compared. The results show that the working resistance of the extrusion head with bionic surface structure is obviously lower than that of the extrusion head with smooth structure in the interaction with soil, and the most obvious drag reduction effect is the vertical concave extrusion head, which reduces the resistance by 17% compared with the smooth extrusion head. The results of the finite element simulation are in good agreement with the experimental results, which proves that the surface of the designed vertical concave bionic geometric structure has the function of reducing viscosity and resistance.