Calibration of the discrete element method and the effect of particle shape
Calibration of the discrete element method and the effect of particle shape
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DOI：
10.1016/j.powtec.2016.04.003
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发表时间：
2016-09-01
影响因子：
5.2
通讯作者：
Coetzee, C. J.
中科院分区：
文献类型：
--
作者：
Coetzee, C. J.
离散单元法（DEM）被广泛应用于各种场合。然而，只有仔细选择输入参数，才能做出准确的预测。本文提出了一种校准过程，用于校准尺寸达40 mm的破碎岩石颗粒的参数值。为此设计并建造了一个直径为590 mm的大型剪切箱。采用侧限压缩试验确定颗粒刚度，采用直剪试验确定颗粒间摩擦系数。使用两种方法来产生团块颗粒：手动过程和优化过程以产生包括2个、4个或8个球体的团块。单独校准团块类型，以获得每种类型的唯一一组参数值。休止角通常用于颗粒-颗粒摩擦系数的校准，并被包括在校准过程中，以与直接剪切试验结果进行比较。校准过程进行了验证，通过建模锚拔出试验和料斗排放使用不同的团块类型。结果表明，用休止角标定颗粒-颗粒摩擦系数时应慎重。尽管可以准确地预测休止角，但它可能导致摩擦值太低而不能用于其他应用。(C)2016爱思唯尔B. V.保留所有权利。
The discrete element method (DEM) is used across a wide range of applications. However, accurate predictions can only be made if the input parameters are carefully selected. In this paper a calibration process is proposed to calibrate the parameter values for crushed rock particles up to 40 mm in size. A large shear box with a diameter of 590 mm was designed and built for this purpose. Confined compression tests were used to determine the particle stiffness and direct shear tests to determine the particle-particle friction coefficient. Two methods were used to create the clump particles: a manual process and an optimised process to-create clumps comprising of 2, 4 or 8 spheres. The clump types were individually calibrated to obtain a unique set of parameter values for each. The angle of repose is often used for the calibration of the particle-particle friction coefficient and was included in the calibration process for comparison with the direct shear test results. The calibration process was validated by modelling anchor pull-out tests and hopper discharge using the different clump types. The results showed that care should be taken when the angle of repose is used to calibrate the particle-particle friction coefficient. It can result in a friction value which is too low for use in other applications, although the angle of repose is accurately predicted. (C) 2016 Elsevier B.V. All rights reserved.