摘要
【目的】蔗段作为大长径比秆状物料,其离散元模型的构建方法与仿真参数的设定尚不清楚,仿真模型精度对颗粒间的动力学响应特性有较大影响,需通过参数标定提高仿真参数的准确性。【方法】以蔗段物理堆积角为响应值,采用仿真试验方法优化标定离散元参数。首先,采用物理试验测定蔗段的基本物性参数,并基于多球聚合模型和XML的方法构建蔗段仿真模型;然后,应用Plackett-Burman试验对蔗段离散元仿真中的8个初始参数进行显著性筛选,并对显著性参数进行最陡爬坡试验,确定最优参数区间;最后,基于Box-Behnken试验建立显著性参数与堆积角的二阶回归方程,以物理试验堆积角42.70°为目标值,对回归方程进行优化求解。【结果】显著性筛选试验得出蔗段泊松比、蔗段−蔗段静摩擦系数、蔗段−蔗段滚动摩擦系数对仿真堆积角影响显著;最优参数组合为:蔗段泊松比0.35、蔗段−蔗段静摩擦系数0.53、蔗段−蔗段滚动摩擦系数0.04。最优参数组合的仿真试验结果表明,仿真堆积角与物理试验堆积角无显著性差异,两者相对误差为0.99%,进一步验证了蔗段离散元标定参数的可靠性。【结论】蔗段离散元模型与最优仿真参数可用于蔗段离散元仿真试验,并可为大长径比秆状农业物料的离散元参数标定提供参考。
【Objective】The construction method of discrete element model and the setting of simulation parameters of sugarcane segment as stalk material with large length and diameter ratio are not clear,the accuracy of the model has a great influence on the dynamic response characteristics between particles,and the accuracies of the simulation parameters need to be improved by parameter calibration.【Method】Taking the physical repose angle of sugarcane segment as the response value,the discrete element parameters were optimized and calibrated by simulation test method.Firstly,the basic physical parameters of sugarcane segment were measured by physical test,and the sugarcane segment simulation model was constructed based on the multi-sphere polymerization model and XML method.Then,the Plackett-Burman test was used to screen the significance of eight initial parameters in the discrete element simulation of sugarcane segment,and the optimal value ranges of significant parameters were determined by the steepest ascent search test.Further,the second-order regression equation between the significant parameters and repose angle was established based on the Box-Behnken test,and taking the physical repose angle of 42.70°as the target value,the regression equation was optimized.【Result】The significance screening test showed that the Poisson’s ratio of sugarcane segment,the static and dynamic friction coefficients between two sugarcane segments had significant influence on the simulated repose angle.The optimal parameter combination was as follows:The Poisson’s ratio of sugarcane segment was 0.35,the static and dynamic friction coefficients between sugarcane segments were 0.53 and 0.04 respectively.The simulation test results of the optimal parameter combination showed that there was no significant difference between the simulated repose angle and the physical repose angle,and the relative error between them was 0.99%,which further verifies the reliability of sugarcane segment parameters calibrated by discrete element method.【Conclusion】The sugarcane segment discrete element model and the optimal simulation parameters can be used in the sugarcane segment discrete element simulation test,and can provide a reference for calibration of the discrete element parameter of stalk agricultural materials with large length and diameter ratio.
作者
任甲辉
武涛
刘庆庭
莫王玉洁
李珂
REN Jiahui;WU Tao;LIU Qingting;MO Wangyujie;LI Ke(College of Engineering,South China Agricultural University,Guangzhou 510642,China)
出处
《华南农业大学学报》
CAS
CSCD
北大核心
2022年第3期124-132,共9页
Journal of South China Agricultural University
基金
国家自然科学基金(52175227)
广东省甘蔗剑麻产业技术体系创新团队(2022KJ104-11)
国家糖料产业技术体系(CARS-170402)。
关键词
离散元
标定
优化
仿真参数
堆积角
蔗段
Discrete element
Calibration
Optimization
Simulation parameter
Repose angle
Sugarcane segment
