橢球顆粒隨機(jī)緊密堆積實驗研究
發(fā)布時間：2018-12-06 22:10
【摘要】：針對隨機(jī)堆積問題在數(shù)理領(lǐng)域和實際生產(chǎn)中意義重大且目前尚無一般性的理論模型的問題,采用一種基于高分辨率工業(yè)X射線斷層掃描(CT)無損檢測的實驗方法較精確地測定了橢球顆粒隨機(jī)緊密堆積體系的3個重要參數(shù),即堆積分?jǐn)?shù)、取向序和配位數(shù)分布,結(jié)果表明,橢球縱橫比為0.5左右時,堆積分?jǐn)?shù)達(dá)到的最大值為74%,與現(xiàn)有的模擬結(jié)果一致,而在一定縱橫比范圍內(nèi),配位數(shù)的分布呈偏態(tài)分布,取向角與取向軸呈現(xiàn)出高對稱性,但離散性較強(qiáng),該結(jié)果與球體隨機(jī)緊密堆積的差異較大。在不考慮摩擦剛體所需平均配位數(shù)為剛體自由度的2倍、有限堆積物的配位數(shù)分布滿足古典的幾何分布的2個假設(shè)下,提出了一種橢球的堆積理論,其能解釋堆積參數(shù)的變化趨勢。結(jié)論和實驗手段對探討非球體填充理論和計算堆積體孔隙率有一定的參考價值。
[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.
【作者單位】： 西安交通大學(xué)理學(xué)院;
【基金】：國家自然科學(xué)基金資助項目(11374237) 中央高�；究蒲袠I(yè)務(wù)費專項資金資助項目(xjj2016060)
【分類號】：O347.7
，
本文編號：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.
【作者單位】： 西安交通大學(xué)理學(xué)院;
【基金】：國家自然科學(xué)基金資助項目(11374237) 中央高�；究蒲袠I(yè)務(wù)費專項資金資助項目(xjj2016060)
【分類號】：O347.7
，
本文編號：2366734
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