蚕豆物性参数测定与离散元仿真参数标定

Determination of Physical Parameters of Broad Bean and Calibration of Discrete Element Simulation Parameters

采用离散元法对蚕豆与收获机具间的相互作用进行数值仿真研究,实现对蚕豆收获机具关键部件相关参数的设计与优化,以提高研究效率、减少研究成本。为此,通过物理试验对蚕豆基本物性参数、接触力学参数和休止角进行测定,参考物理试验测定结果选取仿真试验参数取值范围。以仿真试验休止角为响应值,由Plackette-Burman(PB)试验得到显著影响休止角的试验参数(蚕豆-蚕豆静摩擦因数、蚕豆-钢板静摩擦因数、蚕豆-钢板滚动摩擦因数),并利用最陡爬坡试验在PB试验基础上得到显著参数的取值范围。采用Box-Behnken(BB)试验在休止角与显著参数之间建立二阶回归模型,以休止角物理试验测定值为目标值,对显著参数进行寻优,获得最优参数组合,即蚕豆-蚕豆静摩擦因数0.25、蚕豆-钢板静摩擦因数0.47、蚕豆-钢板滚动摩擦因数0.35。最后,通过T检验得到P>0.05,表明采用最优参数组合得到的休止角仿真值与实测值相差无几,验证了最优参数组合的可靠性。

Numerical simulation research on the interaction between broad bean and harvesting machine is carried out by discrete element method(DEM),to realize the design and optimization of relevant parameters of key components of broad bean harvesting machine,improve research efficiency and reduce research cost.Before this,it is necessary to determine broad bean discrete element simulation parameters.In this paper,the basic physical parameters,contact mechanical parameters and angle of repose of broad bean are measured through physical tests,and the value range of simulation test parameters is selected with reference to the measurement results of physical tests,and the simulation test angle of repose is used as the response value.The test parameters with significant influence of angle(broad bean-broad bean static friction factor,broad bean-steel plate static friction factor,broad bean-steel plate rolling friction factor);on the basis of the Plackette-Burman test,the value range of the significant parameters was determined by the steepest climbing test;the Box-Behnken test establishes the second-order regression model between the angle of repose and the significant parameters.Taking the angle of repose as the target value measured by the physical test,the significant parameters are optimized to obtain the optimal parameter combination:broad bean-broad bean static friction factor 0.25,broad bean-steel plate The static friction factor is 0.47,and the rolling friction factor of broad bean-steel plate is 0.35.Finally,P>0.05 was obtained by T test,which indicated that there was no significant difference between the simulated angle of repose of the optimal parameter combination and the actual angle of repose,which verified the reliability of the optimal parameter combination.The research results show that the discrete element simulation parameters of broad bean calibrated by the above experiments can provide a reference for the optimal design and discrete element simulation research of broad bean harvesting machines.