一种三维颗粒圆度评价方法

颗粒圆度是影响颗粒材料力学性质的重要形态参数之一。相较于三维方法，传统二维圆度评价方法中颗粒与其二维模型的对应关系不唯一，评价结果受主观选择的投影角度影响。以Wadell提出的“颗粒棱角区域”和“颗粒圆度”的定义为逻辑起点，对三维颗粒的圆度评价进行研究，引入“环邻域”和“区域相对连通面积”概念，消除了颗粒棱角识别中粗糙度与棱角度的相互干扰，在传统圆度定义及二维圆度指标的基础上，提出三维颗粒圆度指标，将该指标与重叠离散元颗粒簇ODEC（overlapping discrete element cluster）相结合，提出三维颗粒圆度评价方法。将该方法与现有二维方法在圆度评价精度和算法可靠性方面进行对比，结果显示该方法对各种分辨率的颗粒模型兼容性较好，能对颗粒进行圆度进行相对精确和客观的评价。

An approach to 3D particle roundness quantification

Particle roundness is one of the key factors that influence the mechanical behavior of granular material, however, most existing roundness evaluation approaches are based on visual comparison, those methods always rely on the operator’s experience. In this study, based on 3D ballast model and definition about ‘particle corner’ and ‘particle roundness’ proposed by wadell H, a three-dimensional roundness index was proposed, combine this index with ODEC method, a robust 3D particle roundness evaluation method was included. The method is then used to evaluate the roundness of ballast particles, the result is consistent with former studies, it also shows that the method is well suits for 3D particle models with high resolution and more accurate and objective than other existing approaches when evaluating a single particle model.