离散元模拟中沙土参数标定方法研究

发布时间：2018-03-17 07:49

本文选题：沙土　切入点：参数标定　出处：《农业机械学报》2017年03期 　论文类型：期刊论文

【摘要】：农业机械与土壤相互作用仿真时,选用颗粒相互作用参数的准确度将直接影响仿真结果。本文提出一种通过试验与模拟相结合系统地标定沙土颗粒相互作用参数的方法。通过堆积角测试装置、三轴剪切试验仪、图像颗粒分析系统等设备测量计算沙土的堆积角、剪切模量、粒径分布和外观形貌等参数,为颗粒或工厂建模提供参考。使用标准球和非标准球对沙土颗粒的碰撞恢复因数、静摩擦因数、滚动摩擦因数进行标定。研究不同质量和不同标定方法(抽板法和漏斗法)是否对堆积角产生影响。模拟结果表明,选用标准球标定时,碰撞恢复因数是0.15,静摩擦因数是0.8,滚动摩擦因数是0.2,抽板法得到的堆积角是33.99°,相对误差是4.74%;漏斗法得到的堆积角是33.59°,相对误差是3.51%。同时,选用非标准球进行标定时,碰撞恢复因数是0.15,静摩擦因数是0.2,滚动摩擦因数是0.3,抽板法得到的堆积角是32.06°,相对误差是1.20%。由此看出,颗粒外观形貌对颗粒间静摩擦因数影响相对较大。
[Abstract]:Agricultural machinery and soil interaction simulation, the particle interaction parameters will directly affect the accuracy of the simulation results. This paper presents a method to calibrate the interaction parameters of sand particles by the combination of experiment and simulation system. Through the stacking angle measuring device, the three axle shear test instrument, particle image analysis systems and other equipment measurement sand pile angle, shear modulus, particle size distribution and appearance parameters, provide the reference for the particle or plant modeling. Using the standard and non standard ball collision ball on the sand particles recovery factor, static friction coefficient and rolling friction coefficient calibration. Study of different quality and different calibration methods (pumping plate method and funnel method) the influence of stacking angle. The simulation results show that the selection of standard ball calibration, the collision recovery factor is 0.15, the static friction coefficient is 0.8, the rolling friction coefficient is 0.2, pumping plate Get the stacking angle is 33.99 degrees, the relative error is 4.74%; the funnel method to get the stacking angle is 33.59 degrees, the relative error is 3.51%. at the same time, calibration using non standard ball collision recovery factor is 0.15, the static friction coefficient is 0.2, the rolling friction factor is 0.3, the accumulation of pumping plate method is the angle 32.06 degrees, the relative error is 1.20%., which shows that the appearance of particle particle between the static friction coefficient influence is relatively large.

【作者单位】：吉林大学工程仿生教育部重点实验室;
【基金】：国家自然科学基金项目(51675221、51275199) 吉林省科技发展计划项目(20140101074JC)
【分类号】：S152

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