Friction-Reduction Mechanism and Performance Optimization of Biomimetic Non-Smooth Surfaces Inspired by Dung Beetle Microstructures

Agricultural machinery components suffer from severe soft abrasive wear when interacting with flexible materials like rice stalks. To address this, we investigate the friction-reduction mechanism, parameter optimization, and experimental validation of a biomimetic non-smooth surface inspired by the dung beetle’s microstructure. The bionic design was first established by characterizing the beetle’s unique micro-bump array. To ensure simulation accuracy, the critical bonding parameters of a flexible rice stalk DEM model were precisely calibrated via three-point bending tests combined with Response Surface Methodology (RSM). Subsequent DEM simulations revealed that the bionic surface disrupts continuous sliding by reducing the contact area and inducing high-frequency micro-vibrations in the stalk. Using RSM, the bump geometry was systematically optimized, yielding an optimal combination of a 2.975 mm diameter and a 1.0 mm spacing, which theoretically reduces the average normal contact force by 69.3%. Finally, reciprocating wear tests confirmed that the optimized bio-inspired surface exhibited significantly lower mass loss and effectively suppressed the formation of plowing grooves compared to a smooth surface, showing high agreement with simulation predictions. This study provides both a fundamental understanding of the friction-reduction mechanism and precise quantitative guidance for engineering wear-resistant agricultural components.