Towards an innovative modular cutter of leeks for improving retained stalk quality and prolonging tool life

Smooth cross-section and consistent stubble height are of importance for retained stalk quality of leek. The commonly-used cutting tools are prone to suffer from severe friction due to their high-speed rotation on the rough field ground. Surely, the high-speed rotation results in not only violent worn on the blade tip but also uneven cross-section and inconsistent stubble height. This study proposed to develop an innovative modular cutting tool based on the indexable mechanism in mechanical engineering for either improving the retained stalk quality or prolonging the tool life. Firstly, the discrete element model for the leek stalk was calibrated using shear tests, with a minimal relative error of 0.36% observed for the peak cutting force. The coupled DEM-MBD simulation method was employed to analyze interaction forces and failure forms of the leek stalks during the cutting process, optimizing blade angle of the modular cutting tool. The optimized modular cutting tool reduced peak force compared with the conventional rotary tool and unoptimized modular cutting tool (by 34% and 16%, respectively). Results of the bench test show that the optimized modular cutting tool reduced tip breakage rate and incomplete cutting rate of retained stalks by 75% and 50%, respectively, but increased the oblique cutting rate by 33% relative to the conventional rotary tool. Additionally, the corrected smoothness index ([Formula: see text]) of cross-section was improved by 53.95%. These results highlight the potential of the modular cutting tool to improve harvesting efficiency and stalk quality in field applications.