【摘要】 从细观尺度研究颗粒材料的应变局部化有助于深刻理解其物理力学机制，而剪切带的出现和演化是应变局部化的典型特征。目前在离散元法（DEM）模拟中对砂土应变局部化特征（如剪切带宽度、倾角、分布类型等性质）的观测方法还主要依赖手动、目测和估计等方式。针对这一问题，采用PFC^2D开展了大量密砂双轴压缩模拟试验，提出了一种基于“α-shape”和“Delaunay三角化”算法的剪切带及其宽度的自动识别方法。进而，基于多组砂土试样开展双轴压缩试验，验证了所提出的剪切带及其宽度自动识别方法的有效性。更多还原

【Abstract】 Studying the strain localization of granular materials from the meso-scale is helpful for deeply understanding the physical and mechanical natures of strain localization, and the occurrence and evolution of shear bands are the typical characteristics of strain localization. In the numerical simulations of discrete element method（DEM）, observing and measuring the evolution of strain localization of sand（such as the width, inclination angle and distribution type of shear bands, etc.）greatly rely on the manual, visual and estimation ways. Towards this problem, many numerical experiments on the dense sands in biaxial compression are carried out by using PFC^2D. Based on the numerical experiments, an identification method based on “α-shape” and “Delaunay triangulation” algorithms is developed to automatically identify the shear bands and their widths.Furthermore, based on some groups of biaxial compression tests on the dense sands, the effectiveness of the proposed automatic identification method is validated.更多还原