Study on influence of gradation characteristics on fluidity of granular column collapse via DEM
In order to study the influence of different gradation characteristics on the collapse fluidity of a granular column,standard deviation is used to describe the gradation curve,and samples with different gradation characteristics are constructed for discrete element numerical experiments on granular column collapse.The mobility and normalized stacking height of granular columns with different gradation characteristics are analyzed.The reason for the high fluidity of granular column is explained emphatically from the perspective of average coordination number and energy.The results show that the collapse of the granular column is mainly sliding when the aspect ratio is less than the critical aspect ratio;and mainly dumping otherwise.When the standard deviation is less than 0.2,the mobility and normalized stacking height of granular column gradually decrease.Under short column conditions,the normalized dissipative energy increases with increasing standard deviation,while the average coordination number decreases for aspect ratios is below 1.0.As the standard deviation increases,the dissipated energy decreases and the average coordination number increases.This illustrates the meso-mechanism of increasing fluidity.
granular column collapse experimentgradation characteristicsdiscrete element methodfluidity
万方数据
维普
