多模态振动下木薯-土壤复合体分离机理与降耗研究

Separation Mechanism and Energy Consumption Optimization of Cassava - Soil Composite under Multimodal Vibration

摘要:

针对木薯收获过程中土壤破碎质量差、薯土分离能耗高等问题，引入非线性累积冲击损伤系数，建立木薯 - 土壤复合体累积冲击能量耗散模型，通过物理试验与仿真模拟，对比了稳态正弦、线性扫频与对数扫频 3 种振动模式下土壤颗粒空间轨迹偏移量 (s?)、薯土分离率 (Q_c) 及单位分离比能 (E_SR) 的影响规律，揭示了土壤空间运移特性与能量耗散机制。结果表明，木薯压缩与土壤锥入仿真与物理试验相对误差分别为 0.98% 与 0.21%。3 种振动模态下，s?与 Q_c 均呈正相关关系;线性扫频与对数扫频激励模式下，扫频范围对 Q_c 与 E_SR 影响均显著。其中，6Hz、15mm 稳态正弦激励模式下，薯土分离率较优，为 89.50%, 单位分离比能为 0.32J/%;起始频率 3Hz、终止频率 9Hz、振幅 15mm 的线性扫频激励模式下，薯土分离率较优，为 76.75%, 单位分离比能为 0.37J/%;起始频率 6Hz、终止频率 9Hz、振幅 12.5mm 的对数扫频激励模式下，薯土分离率较优，为 83.92%, 单位分离比能为 0.46J/%。研究完善了木薯 - 土壤 - 振动模态间的互作理论，为低能耗木薯收获装备开发提供了理论依据与参数指导。

Abstract:

Aiming at the problems of poor soil fragmentation quality and high energy consumption in cassava harvesting, a cumulative impact energy dissipation model of cassava - soil complex was established. By integrating physical experiments with simulation modeling, a high-precision cassava - soil composite model was established. The effects of three vibration modes-steady-state sinusoidal, linear frequency sweep, and logarithmic frequency sweep-on soil particle spatial trajectory displacement (S_r), cassava-soil separation rate (Q_cs),and energy consumption per unit separation rate (E_SR) were compared, revealing the spatial movement characteristics of soil and the underlying energy dissipation mechanisms. Results showed that the relative errors between simulation and physical tests were 0. 98% for cassava compression and 0. 21% for soil cone penetration. Under all three vibration modes, S_r was positively correlated with Q_c, with the strongest correlation observed under steady-state sinusoidal excitation. In linear and logarithmic sweep frequency modes, the sweep range had no significant effect on S_r but significantly influenced both Q_cs and E_SR. Notably, steady-state sinusoidal excitation performed best at 6 Hz and 15 mm, achieving Q_c of 89. 50% while maintaining E_SR at a relatively low level of 0. 32 J/%;for linear sweep frequency excitation, the optimal parameters were a starting frequency of 3 Hz, ending frequency of 9 Hz, and amplitude of 15 mm, yielding Q_c of 76. 75% and E_SR of 0. 37 J/%;logarithmic sweep frequency excitation performed optimally at a starting frequency of 6 Hz, ending frequency of 9 Hz, and amplitude of 12. 5 mm, achieving Q_c of 83.92% and E_SR of 0. 46 J/%. The research refined the interaction theory among cassava, soil and vibration modes, providing theoretical basis and parameter guidance for the development of low-energy cassava harvesting equipment.