Design and Research of a Cutting Blade for Corn Stalks Based on a Bionic Principle

Abstract

The ant (Pheidole megacephala, Fabricius) has a unique and hard mandibular structure to cut branches and crush hard food. Inspired by this special geometric structure of the mandibular teeth, a stereoscopic microscope was used to view the image of the mandible of the ant. The Origin and AutoCAD software were used to obtain the outer profile of the mandibular teeth of the ant. The outer profile of the ant's mandibular teeth was fitted and expressed by five-order polynomial function. According to the analysis of the profile curve of the maxillary teeth, the fourth tooth is the most convex and the sharpest. The fourth tooth of the ant plays a key role in its feeding process, therefore, the structural parameters of the fourth maxillary tooth were selected as bionic elements for bionic blade design. To compare the cutting performance of the bionic and ordinary flat blades, the performance of bionic blade and the ordinary blade were conducted by using ANSYS software, the cutting force-deformation characteristics were tested using the Rapid TA practical texture analyser. The results of the element simulation showed that the mechanical properties of bionic blade were better than those of the ordinary blade. The results of the cutting experiments indicated that under the loading speed of 5 mm/s, the maximum cutting force of the bionic blade was 137.51 N, which is 12.17 % lower than that of the ordinary flat blade. The average cutting force of the bionic blade was 96.56 N, which is 11.58 % lower than that of the ordinary flat blade. The cutting energy consumption of the bionic blade was 9.68 J, which is 11.92 % lower than that of the ordinary flat blade. Under the loading speed of 10 mm/s, the maximum cutting force of the bionic blade was 143.88 N, which is 10.37 % lower than that of the ordinary flat blade. The average cutting force of the bionic blade was 101.03 N, which is 9.77 % lower than that of the ordinary flat blade. The cutting energy consumption of the bionic blade was 10.14 J, which is 9.95 % lower than that of the ordinary flat blade. The experimental results suggested that the bionic blade can effectively reduce the cutting force and energy consumption; thus, the bionic blade is more suitable for cutting stalks. These results will be helpful in the development of cutting elements for cutting and chopping of corn stover and other processing machinery.