摘要
干式轻质异形介质是滚磨光整加工中常用的一类加工介质,其形状各异,导致离散元仿真中所使用的接触参数难以测试与标定,影响仿真模拟的准确性。以核桃壳介质为研究对象,首先通过物理试验测得核桃壳介质的几何形态、密度以及弹性/剪切模量等本征参数,其次采用自制的接触参数测量装置获得核桃壳介质与亚克力板间的静摩擦系数、滚动摩擦系数、碰撞恢复系数及核桃壳介质间的碰撞恢复系数,最后基于不同形状的特征参数,采用多维法构建出24种干式异形介质单颗粒仿真模型,并以实际堆积角为目标进行寻优,开展2因素5水平旋转正交组合仿真模拟试验,获得核桃壳介质间的静摩擦系数和滚动摩擦系数的最佳参数组合:静摩擦系数为0.829、滚动摩擦系数为0.191。采用测试及标定的本征参数和接触参数进行不同挡板抬升速度下的堆积角仿真,并与试验结果对比,最大相对误差<4%。
Objectives:Dry light-shaped medium is a type of machining medium commonly used in the rolling finishing process.Its shape varies,making it difficult to test and calibrate the contact parameters used in discrete element simulation,which affects the accuracy of the simulation.In this study,walnut shell medium is taken as the research object,and the intrinsic parameters and contact parameters of walnut shell medium are tested based on the basic parameter measurement methods of granular material,both domestically and internationally.The friction coefficient between the medium is calibrated with the accumulation angle obtained by the experiment as the response value,in order to provide parameter support for the discrete element simulation of dry light-shaped medium roller grinding.Methods:The density of walnut shell medium is obtained using oil discharge method and the measuring cylinder method.The elastic/shear modulus is measured by the texture analyzer.The shape characteristic parameters are measured by the PartAn 3D particle dynamic image analyzer,and the shapes are classified by the multi-dimensional method.Based on the strong correlation between two-dimensional and three-dimensional shape characteristic parameters,a single particle simulation model of 24 types of dry-shaped media is constructed,and the dry-shaped media are bonded into particle plates.The collision recovery coefficient between the dry-shaped media is measured by the inclined plate collision experiment.The static friction coefficient,rolling friction coefficient,and collision recovery coefficient between the dry-shaped medium and acrylic are obtained using a self-made contact parameter measuring device.Taking the actual packing angle as the test object and the friction coefficient between the walnut shell media as the factor,a two-factor five-level rotation orthogonal test is carried out to establish the second-order regression equation of the friction coefficient and packing angle.The actual packing angle,as the target value,is optimized.The discrete element simulation and experiment are combined to determine the best parameter combination of the static friction coefficient and the dynamic friction coefficient between the dry-shaped media.Results:(1)The physical experiment results show that the real density of walnut shell medium is 1024 kg/m^(3),the packing density is 642 kg/m^(3),and the shear modulus is 9.219×10^(7) Pa.(2)The collision recovery coefficient between the walnut shell medium and the acrylic plate is 0.246,the static friction coefficient is 0.422,the rolling friction coefficient is 0.175 and the collision recovery coefficient between the walnut shell medium is 0.340.(3)The actual stacking angle is the target value for optimization,and the optimal parameter combination of friction coefficient between dry-shaped media is determined by combining discrete element simulation and experiment:the static friction coefficient between walnut shell media is 0.829,and the rolling friction coefficient is 0.191.(4)The stacking test is carried out on the stacking angle under different baffle lifting speeds,and the relative error between the simulated and actual stacking angle is less than 4%,which proves that the parameter combination can be effectively used for EDEM simulation process analysis.Conclusions:In this paper,the relevant parameters of walnut shell medium are measured and calibrated by combining experiment and simulation.Based on the multidimensional shape classification and the strong correlation between two-dimensional and three-dimensional morphological features,a single particle simulation model of dry-shaped medium can be effectively constructed.In this way,the calibrated walnut shell medium particle model can more truly simulate the interaction between walnut shell medium,parts,and processing equipment,and analyze and predict from a microscopic point of view.In the future,this method can be used for parameter testing and calibration of shaped media such as corncob and olive shell,thereby expanding the application range of the dryshaped media calibration method.
作者
梁志强
李秀红
王兴富
李文辉
杨胜强
梁振华
LIANG Zhiqiang;LI Xiuhong;WANG Xingfu;LI Wenhui;YANG Shengqiang;LIANG Zhenhua(College of Mechanical and Vehicle Engineering,Taiyuan University of Technology,Taiyuan 030024,China;Shanxi Key Laboratory of Precision Machining,Taiyuan University of Technology,Taiyuan 030024,China;College of Aeronautics and Astronautics,Taiyuan University of Technology,Jinzhong 030600,Shanxi,China)
出处
《金刚石与磨料磨具工程》
北大核心
2025年第1期122-133,共12页
Diamond & Abrasives Engineering
基金
国家自然科学基金(51975399,51875389)
中央引导地方科技发展资金(YDZJSX2022A020,YDZJSX2022B004)。
关键词
离散元
核桃壳介质
参数标定
摩擦系数
堆积角
discrete element
walnut shell medium
parameter calibration
coefficient of friction
stacking angle
