基于离散元法的玉米籽粒建模

Modeling method of maize kernels based on discrete element method

对十余个品种玉米籽粒的几何形状、尺寸参数及各尺寸间的相关性进行了测试分析。在这些分析的基础上,提出了一种基于球充填的单个玉米籽粒和玉米籽粒群体的建模方法。以2个品种玉米籽粒为例,通过玉米籽粒堆积试验和"自流筛分"试验的试验结果与其离散元法仿真结果的对比分析可知,当单个玉米籽粒模型的充填球数为16时,所建立的玉米籽粒群体与实际玉米籽粒群体较相近,由此初步证明了本文提出的玉米籽粒建模方法的可行性和有效性。最后,通过一个实例,介绍了如何使用玉米籽粒模型和离散元法对粮仓卸料过程进行分析。

The geometric shapes,size parameters and correlations between dimensions of more than ten maize varieties are measured and analyzed.On the basis of the analyses,a modeling method of a single maize kernel and a maize assembly is proposed based on the sphere filling method.Two maize varieties are selected as examples.By comparison of the experimental results and the Discrete Element Method（DEM）simulation results of the maize kernel packing tests and ＂elf-flow screening＂tests,respectively,it is concluded that when the number of the filling spheres is 16 for a single maize kernel,agood agreement between them is reached.The effectiveness of the maize kernel modeling method proposed in this work is verified.A case is used to show how to employ the maize kernel model and DEM to analyze the discharge process of a silo.