级配碎石形状量化及其对堆积特性的影响

针对现有离散元模拟多采用规则形状颗粒进行，与颗粒实际形态不符的缺陷。以级配碎石为例，对颗粒形状进行量化分析。采用数字图像处理技术，得到颗粒轮廓，根据轮廓形态特征从多个层次对颗粒形态进行描述，并得到互相独立的扁平度、棱角度形状指标，对指标进行统计分析，发现颗粒形态与粒径无关。最后通过离散元数值模拟探究颗粒真实形态与颗粒堆积孔隙率关系。试验结果表明：在松散情况下，堆积孔隙率随扁平度的增大而增大，而当颗粒近似圆形时，孔隙率随棱角度增大而减小。

Quantifying the shape features of graded broken stone and its impacts on#br# the packing behaviors

Given that most of existing DEM simulations are based on regular polygonal particles, which is greatly differ from realistic particle shapes, this study quantifies the shape features of broken graded stones. By using the Digital image processing technique, the particle contours are acquired. From the acquired contours, the particle shape features are analyzed by using several shape indexes that belong to different scales. The statistical analysis demonstrates that these indexes, namely aspect ratio and angularity are independent from the particle size. The DEM simulation is afterwards employed to investigate the relationship between particle shape features and void ratio of porous granular materials. The result demonstrates that the void ratio increases when the aspect ration increase, while the void ratio decreases when particles are rounded.