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为了探讨不同块根拔起速度和块根生长状况对块根最大拔起力的影响规律,该文采用物理试验方法、ANSYS/LS-DYNA显式动力学仿真技术及土力学理论分析方法进行物理试验和力学分析,建立了考虑拔起速度影响的木薯块根拔起力的力学模型和数学模型,且对模型进行了试验验证。结果表明,假设木薯块根对土壤的作用为一圆盘和圆盘外延对土壤的共同作用的力学模型合理;圆盘最大拔起力的数学模型精度高,理论值与实测值的相对误差小于16%;木薯块根最大拔起力的数学模型对成圆盘状分布生长的木薯块根拔起力有较高的预测精度,对生长分布较不均匀的木薯块根拔起力的预测精度较低,但理论值与实测值的相对误差也小于27%;木薯块根最大拔起力随拔起速度、块根圆盘直径和圆盘深度的增大而增大;块根圆盘深度对木薯块根的最大拔起力的影响最大,其次是圆盘直径,最后是拔起速度。该文为挖拔式木薯收获机械块根拔起机构系统的设计提供依据。
In order to study the influence of rooting speed and root growth on the maximum pullout of root tuberous root, physical experiment and mechanics were carried out by using physical test method, ANSYS / LS-DYNA explicit dynamic simulation technology and soil mechanics theory analysis method The mechanics model and mathematical model of cassava root uplift force were established based on the analysis of the pull-up speed. The model was verified by experiments. The results show that it is reasonable to assume that the cassava root acts on the soil as a mechanical model of disc and disc extension on the soil interaction. The mathematical model of maximum disc pull-up is accurate and the relative error between the theoretical and measured values is less than 16 %. The mathematical model of maximum cassava root uptake has a higher predictive accuracy for carapace root uplift with discoid distribution, but lower prediction accuracy for cassava root uplift with less uniform growth distribution. However, The relative error between the theoretical value and the measured value was less than 27%. The maximum pull-out force of cassava roots increased with the rising speed, the diameter of the disk and the depth of the disk. The greatest impact of force, followed by the disc diameter, the last is pulled up speed. This article provides the basis for the design of pick-up cassava harvesting machine root-up mechanism system.