Biomimeitc Design of a Stubble-Cutting Disc Using Finite Element Analysis

Mole rat (Scaptochirus moschatus), a soil-burrowing mammal, can efficiently dig soil using its fore claws. The profile curves of its claw toe provide excellent structure for digging. In this paper, a biomimetic stubble-cutting disc was designed by learning from the geometrical characteristics of the mole rat claw toes. To compare the structural strength and working efficiency of the biomimetic disc and the conventional stubble-cutting disc, three-dimensional (3D) models of the discs were built and numerical analyzed in ABAQUS. In the dynamic soil cutting model, soil was modeled as an elastic-plastic material with elastic parameters, including Young's modulus, Poisson's ratio and Drucker-Prager criterion, which were obtained from triaxial tests. A general contact algorithm was used to simulate the interaction between rotary disc and soil. In FEA models, for the combined action of normal and friction stresses, the stress on the biomimetic disc is 34.33% lower than that of the conventional disc, For only the normal stress, the stress on the biomimetic disc is 22.64% lower than that on the conventional one. The magnitude of soil stress in biomimetic disc cutting model is 6.87% higher than that in conventional disc. The FEA results indicate that the biomimetic disc performs better in structural strength and cutting efficiency.