中文摘要：

根据颗粒离散元Kelvin接触力计算模型,分析了圆形颗粒体模拟材料力学特性应具备的条件,在此基础上提出了一种新颗粒模型构建方法。该方法首先在复杂模型域内随机生成种子,然后利用相切条件逐步扩展填充整个区域。填充过程中借助局部Delaunay三角化网格控制新颗粒的生成,采用复杂几何体距离控制颗粒与模型边界的相对位置,对靠近模型边界的颗粒进行容忍性优化填充,从而增加模型颗粒与边界的耦合性。同时对模型孔隙进行再填充,保证每个填充颗粒至少与3个颗粒相切,提高了模型内颗粒间的耦合性和模型的密度。最后采用任意多边形控制材料边界,将模型材料的设置简化为判断点是否在多边形内,简化了复杂模型材料属性的设置过程。结果表明：与膨胀颗粒生成法相比,该方法生成模型重叠量小、颗粒间及颗粒-边界相互耦合、填充率高。因此,颗粒黏结力破坏后不会造成飞溢现象,可适用于任意连通域模型的生成,能更好地实现复杂岩土细观介质变形破坏机制的模拟与研究。

英文摘要：

Based on Kelvin＇s contact force calculation model, the conditions required for simulating the mechanical behavior of the porous materials consisting of spherical particles are analyzed, from which a new granular model construction method is proposed. In this model a seed position is stochastically generated in the complex solution domain; and then it is gradually expanded to fill the entire region. In the filling process a local Delaunay triangulation mesh control is used to generate new particles; and particle distance control in a complex geometry boundary is used to decide the relative position of a new generated particle. For particles near the model boundary, an optimized tolerance position and radius are calculated and filled, which enhances the coupling characteristic between boundary and the particles. Meanwhile, the pore position can be refilled to ensure that each particle is tangent with at least three particles in order to improve the coupling characteristic between model particles. Finally, arbitrary polygons are used to divide several materials. The model region will be simplified for judging whether the polygon point is in the polygon or not, which can simplify the setup process of complex model materials. The results show that the proposed method has small overlap between particles, high filling rate between particles, particle and boundary. The proposed method can decrease flying overflow phenomenon when the adhesive force between particles disappears, and can be used to model construction of random connected domain.