Design and testing of the clam vibration harvester's V-shaped double-spiral harvesting roller brush based on DEM-MBD

Abstract

To address the challenges of low mechanization and the lack of theoretical research in clam harvesting on Chinese mudflats, a brush-screen cooperative clam vibration harvester was developed, and the V-shaped double-spiral harvesting roller brush served as the key component. White clams (Mactra veneriformis) were selected as the research subjects. A theoretical analysis of the harvesting roller brush was conducted, resulting in the derivation of key structural and operational parameter ranges. The Discrete Element Method (DEM) combined with Multi-Body Dynamics (MBD) was employed to simulate single-factor tests, Plackett-Burman tests, and response surface tests in shellfish harvesting. The optimal combination of key structural and operational parameters for the harvesting roller brush was identified as follows: bristle length of 105 mm, 5 bristle rows, bristle thickness of 40 mm, spiral angle of 28°, rotation speed of 48 r/min, and installation positions at X-axis 249 mm and Y-axis 9 mm. Under these conditions, the average mass of residual sediments on the screen surface was 10.59 g, the harvested shellfish mass was 177.4 g, and the shellfish breakage rate was 11.10 %. A prototype shellfish harvester was developed, and field tests demonstrated a harvested shellfish mass of 166.2 g, with a relative error of 8.57 %, a shellfish breakage rate of 7.07 %, an absolute breakage rate error of 4.03 %, and a harvesting efficiency of 292.20 kg/h. This study offers a valuable reference for the design and enhancement of mechanized harvesting for shellfish in mudflats.