基于离散元法的长短轴之比对散粒材料抗剪强度影响分析

发布时间：2018-04-29 05:29

本文选题：杆状颗粒 + 长短轴之比　；参考：《大连理工大学学报》2016年02期

【摘要】：杆状颗粒由于其形状与砾石、药品和谷物等真实颗粒的形状接近而受到研究者们的关注,其形状特征常用长短轴之比进行表征.以往许多学者曾通过离散元法研究过在相同孔隙率下杆状颗粒长短轴之比对其抗剪强度的影响,但在相同相对密度下的研究并不多见.通过控制颗粒摩擦因数形成具有相同相对密度的试样,研究了0%、35%、65%及100%相对密度下颗粒的长短轴之比对试样抗剪强度的影响规律.另外,还进行了相同孔隙率下的试验以进行结果对比.研究结果表明,相同相对密度下,峰值状态和临界状态时试样剪应力随长短轴之比增大而增大,与相同孔隙率下的结果一致,但峰值剪应力增大幅值要比相同孔隙率下的小.另外,对不同长短轴之比下试样内摩擦角进行分析,发现临界状态时内摩擦角随长短轴之比增大而增大,而峰值状态时内摩擦角受长短轴之比的影响相对较小.最后从试样剪胀性方面进行了分析,阐述了以上现象发生的机理.
[Abstract]:Because the shape of rod particles is close to that of gravel, medicine and grain, researchers pay attention to the shape characteristics of rod particles. The ratio of long axis to long axis is used to characterize the shape characteristics of rod particles. In the past, many scholars have studied the effect of the ratio of long and short axis of rod particles on the shear strength under the same porosity by discrete element method, but few studies have been done at the same relative density. By controlling the friction coefficient of particles to form samples with the same relative density, the influence of the ratio of the long and short axes of the particles on the shear strength of the samples with the relative density of 65% and 100% was studied. In addition, experiments with the same porosity were carried out to compare the results. The results show that at the same relative density, the shear stress increases with the increase of the ratio of long and short axes, but the amplitude of the increase of peak shear stress is smaller than that of the same porosity. In addition, it is found that the internal friction angle increases with the increase of the ratio of the long axis to the long axis at the critical state, but the ratio of the long axis to the short axis affects the angle of the internal friction at the peak state relatively little by the ratio of the long axis and the short axis. In the end, the mechanism of the above phenomena is explained by analyzing the shear dilatancy of the sample.
【作者单位】：大连理工大学水利工程学院;
【基金】：国家自然科学基金资助项目(51479027,51539008)
【分类号】：O347.7

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