椭球颗粒随机紧密堆积实验研究
发布时间：2018-12-06 22:10
【摘要】：针对随机堆积问题在数理领域和实际生产中意义重大且目前尚无一般性的理论模型的问题,采用一种基于高分辨率工业X射线断层扫描(CT)无损检测的实验方法较精确地测定了椭球颗粒随机紧密堆积体系的3个重要参数,即堆积分数、取向序和配位数分布,结果表明,椭球纵横比为0.5左右时,堆积分数达到的最大值为74%,与现有的模拟结果一致,而在一定纵横比范围内,配位数的分布呈偏态分布,取向角与取向轴呈现出高对称性,但离散性较强,该结果与球体随机紧密堆积的差异较大。在不考虑摩擦刚体所需平均配位数为刚体自由度的2倍、有限堆积物的配位数分布满足古典的几何分布的2个假设下,提出了一种椭球的堆积理论,其能解释堆积参数的变化趋势。结论和实验手段对探讨非球体填充理论和计算堆积体孔隙率有一定的参考价值。
[Abstract]:In view of the problem that random stacking problem is of great significance in mathematical field and practical production and there is no general theoretical model at present, An experimental method based on high resolution industrial X-ray tomography (CT) nondestructive testing was used to determine three important parameters of ellipsoid random compact packing system, namely, packing fraction, orientation order and coordination number distribution. The results show that when the aspect ratio of ellipsoid is about 0.5, the maximum value of stack integral number is 74, which is consistent with the existing simulation results, but in a certain aspect ratio range, the distribution of coordination number is skewed. There is a high symmetry between the orientation angle and the orientation axis, but the dispersion is strong, and the result is quite different from the random compact packing of the sphere. Under the assumption that the average coordination number of friction rigid body is 2 times of the degree of freedom of rigid body and the distribution of coordination number of finite accumulations satisfies the classical geometric distribution, an ellipsoidal packing theory is proposed. It can explain the variation trend of accumulation parameters. Conclusion and experimental means have certain reference value for discussing the theory of non-sphere filling and calculating the porosity of accumulative body.
【作者单位】： 西安交通大学理学院;
【基金】：国家自然科学基金资助项目(11374237) 中央高校基本科研业务费专项资金资助项目(xjj2016060)
【分类号】：O347.7
，
本文编号：2366734
[Abstract]:In view of the problem that random stacking problem is of great significance in mathematical field and practical production and there is no general theoretical model at present, An experimental method based on high resolution industrial X-ray tomography (CT) nondestructive testing was used to determine three important parameters of ellipsoid random compact packing system, namely, packing fraction, orientation order and coordination number distribution. The results show that when the aspect ratio of ellipsoid is about 0.5, the maximum value of stack integral number is 74, which is consistent with the existing simulation results, but in a certain aspect ratio range, the distribution of coordination number is skewed. There is a high symmetry between the orientation angle and the orientation axis, but the dispersion is strong, and the result is quite different from the random compact packing of the sphere. Under the assumption that the average coordination number of friction rigid body is 2 times of the degree of freedom of rigid body and the distribution of coordination number of finite accumulations satisfies the classical geometric distribution, an ellipsoidal packing theory is proposed. It can explain the variation trend of accumulation parameters. Conclusion and experimental means have certain reference value for discussing the theory of non-sphere filling and calculating the porosity of accumulative body.
【作者单位】： 西安交通大学理学院;
【基金】：国家自然科学基金资助项目(11374237) 中央高校基本科研业务费专项资金资助项目(xjj2016060)
【分类号】：O347.7
，
本文编号：2366734
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