Parameter calibration of a discrete element simulation model for dry lightweight heterogeneous media
-
摘要: 为实现干式轻质异形介质在滚磨光整加工过程中的离散元模拟仿真,本文以核桃壳介质为研究对象,采用多维法对不同形状的核桃壳介质进行划分,并构建不同类型的介质模型,通过物理试验与仿真模拟相结合的方法对其离散元仿真参数进行标定。首先,采用物理试验测得核桃壳介质的本征参数(外形尺寸、密度、弹性/剪切模量),通过搭建自制接触参数测量装置测得核桃壳介质与亚克力间的静摩擦系数、滚动摩擦系数、碰撞恢复系数分别为0.422、0.175、0.246及核桃壳介质间的碰撞恢复系数为0.340。其次,基于EDEM内嵌GEMM数据库确定颗粒介质之间静摩擦和滚动摩擦系数的取值范围,并开展二因素五水平旋转正交组合仿真模拟试验,以实际堆积角44.64°为目标值,建立堆积角与摩擦系数的二阶回归方程,并寻优求解,得到最佳组合:核桃壳介质间的静摩擦系数为0.829、滚动摩擦系数为0.191。最后,通过设置不同挡板抬升速度进行堆积角验证性实验,结果表明,其综合相对误差不超过4%,该参数组合可作为使用核桃壳介质进行滚磨光整加工过程中的离散元仿真模型参数。Abstract: In order to realize the discrete element simulation of dry light shaped particle medium in the process of rolling grinding, in this paper, walnut shell particle medium was taken as the research object, the multi-dimensional method is used to divide the light medium with different shapes , and different types of shaped particle media were constructed , the discrete element simulation parameters are calibrated by the combination of physical experiment and simulation. First of all, the intrinsic parameters (density, elastic modulus and shear modulus) of walnut shell particle medium were measured by physical tests. The static friction coefficient、rolling friction coefficient and collision recovery coefficient between walnut shell particle medium and acrylic are 0.422、0.175 and 0.246, respectively, and the collision recovery coefficient between walnut shell particle medium is 0.340. Secondly, the range of static friction and rolling friction coefficients between granular media is determined based on EDEM embedded GEMM database, and the two-factor five-level rotational orthogonal combination simulation test was carried out, The second-order regression equation of accumulation Angle and friction coefficient was established, aiming at physical accumulation Angle 44.64°, the regression equation was optimized and solved, and the best combination was obtained: The coefficient of static friction between granular media is 0.829、the rolling friction coefficient is 0.191. Finally, by setting the different lifting speed of the baffle, the verification experiment of stacking Angle is carried out. The results show that the comprehensive relative error is less than 4%.It is shown that the parameter combination can be used as a discrete element simulation model parameter in the process of rolling grinding with walnut shell particle medium.
点击查看大图
计量
- 文章访问数: 76
- HTML全文浏览量: 21
- 被引次数: 0