Jun Qian, Shaochun Ma, Yuchi Deng, Fenglei Wang, Yansu Xie, Chao Ma, Jianming Wu, Zhenghe Song
The poor cutting quality of sugarcane stubble is one of the main reasons hindering the improvement of mechanized harvesting rate of sugarcane, while most studies have focused on optimizing the structural and kinematic parameters of the basecutter. However, the biomechanical behavior of the root-soil composite during basecutting and uprooting remains poorly understood, limiting the preservation of stubble integrity. In this study, the basecutting and uprooting mechanism were investigated, and corresponding mechanical models were established to analyze the influencing factors and critical conditions of stubble failures through mechanical analysis. The bonding parameters (normal and shear stiffness, critical normal stress, and critical tangential stress) of root were calibrated through comparing tests to investigate the basecutting behavior. Field tests were conducted to verify the theoretical and simulation results. The biomechanical analysis revealed that cutting resistance increased nonlinearly with cutting depth, and was also affected by cutting frequency, stalk characteristics, and cutter geometry. The anti-uprooting resistance depended on the structural characteristics of roots and soil conditions. The comparison of bonding breakage showed that the bond fracture concentrated near the main root and propagated rapidly upward, indicating abrupt failure of the root-soil composite under the disc-type cutter. In contrast, the sliding-shearing mode induced a more uniform and progressive fracture process, with fewer bond breakage and delayed failure initiation. Field verification tests showed that after optimization, the damage rate of sliding and shearing combined basecutter and disc-type basecutter were 12.96% and 13.39%, respectively. This study provides insight and guidance on biomechanics, simulation, and experiment for optimized basecutter and promoting sustainable development of mechanized harvesting system.